]> git.dujemihanovic.xyz Git - u-boot.git/commitdiff
cli: Add Busybox upstream hush.c file
authorFrancis Laniel <francis.laniel@amarulasolutions.com>
Fri, 22 Dec 2023 21:02:27 +0000 (22:02 +0100)
committerTom Rini <trini@konsulko.com>
Thu, 28 Dec 2023 17:02:56 +0000 (12:02 -0500)
This commit adds new file cli_hush_upstream.c, it is a copy of Busybox hush
file it was of time to Busybox commit 37460f5da.

Signed-off-by: Francis Laniel <francis.laniel@amarulasolutions.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
common/cli_hush_upstream.c [new file with mode: 0644]

diff --git a/common/cli_hush_upstream.c b/common/cli_hush_upstream.c
new file mode 100644 (file)
index 0000000..c970d90
--- /dev/null
@@ -0,0 +1,12162 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * A prototype Bourne shell grammar parser.
+ * Intended to follow the original Thompson and Ritchie
+ * "small and simple is beautiful" philosophy, which
+ * incidentally is a good match to today's BusyBox.
+ *
+ * Copyright (C) 2000,2001  Larry Doolittle <larry@doolittle.boa.org>
+ * Copyright (C) 2008,2009  Denys Vlasenko <vda.linux@googlemail.com>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ *
+ * Credits:
+ *      The parser routines proper are all original material, first
+ *      written Dec 2000 and Jan 2001 by Larry Doolittle.  The
+ *      execution engine, the builtins, and much of the underlying
+ *      support has been adapted from busybox-0.49pre's lash, which is
+ *      Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
+ *      written by Erik Andersen <andersen@codepoet.org>.  That, in turn,
+ *      is based in part on ladsh.c, by Michael K. Johnson and Erik W.
+ *      Troan, which they placed in the public domain.  I don't know
+ *      how much of the Johnson/Troan code has survived the repeated
+ *      rewrites.
+ *
+ * Other credits:
+ *      o_addchr derived from similar w_addchar function in glibc-2.2.
+ *      parse_redirect, redirect_opt_num, and big chunks of main
+ *      and many builtins derived from contributions by Erik Andersen.
+ *      Miscellaneous bugfixes from Matt Kraai.
+ *
+ * There are two big (and related) architecture differences between
+ * this parser and the lash parser.  One is that this version is
+ * actually designed from the ground up to understand nearly all
+ * of the Bourne grammar.  The second, consequential change is that
+ * the parser and input reader have been turned inside out.  Now,
+ * the parser is in control, and asks for input as needed.  The old
+ * way had the input reader in control, and it asked for parsing to
+ * take place as needed.  The new way makes it much easier to properly
+ * handle the recursion implicit in the various substitutions, especially
+ * across continuation lines.
+ *
+ * TODOs:
+ *      grep for "TODO" and fix (some of them are easy)
+ *      make complex ${var%...} constructs support optional
+ *      make here documents optional
+ *      special variables (done: PWD, PPID, RANDOM)
+ *      follow IFS rules more precisely, including update semantics
+ *      tilde expansion
+ *      aliases
+ *      "command" missing features:
+ *          command -p CMD: run CMD using default $PATH
+ *              (can use this to override standalone shell as well?)
+ *          command BLTIN: disables special-ness (e.g. errors do not abort)
+ *          command -V CMD1 CMD2 CMD3 (multiple args) (not in standard)
+ *      builtins mandated by standards we don't support:
+ *          [un]alias, fc:
+ *          fc -l[nr] [BEG] [END]: list range of commands in history
+ *          fc [-e EDITOR] [BEG] [END]: edit/rerun range of commands
+ *          fc -s [PAT=REP] [CMD]: rerun CMD, replacing PAT with REP
+ *
+ * Bash compat TODO:
+ *      redirection of stdout+stderr: &> and >&
+ *      reserved words: function select
+ *      advanced test: [[ ]]
+ *      process substitution: <(list) and >(list)
+ *      let EXPR [EXPR...]
+ *          Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
+ *          If the last arg evaluates to 0, let returns 1; 0 otherwise.
+ *          NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
+ *      ((EXPR))
+ *          The EXPR is evaluated according to ARITHMETIC EVALUATION.
+ *          This is exactly equivalent to let "EXPR".
+ *      $[EXPR]: synonym for $((EXPR))
+ *      indirect expansion: ${!VAR}
+ *      substring op on @: ${@:n:m}
+ *
+ * Won't do:
+ *      Some builtins mandated by standards:
+ *          newgrp [GRP]: not a builtin in bash but a suid binary
+ *              which spawns a new shell with new group ID
+ *
+ * Status of [[ support:
+ * [[ args ]] are CMD_SINGLEWORD_NOGLOB:
+ *   v='a b'; [[ $v = 'a b' ]]; echo 0:$?
+ *   [[ /bin/n* ]]; echo 0:$?
+ *   = is glob match operator, not equality operator: STR = GLOB
+ *   == same as =
+ *   =~ is regex match operator: STR =~ REGEX
+ * TODO:
+ * quoting needs to be considered (-f is an operator, "-f" and ""-f are not; etc)
+ * in word = GLOB, quoting should be significant on char-by-char basis: a*cd"*"
+ */
+//config:config HUSH
+//config:      bool "hush (68 kb)"
+//config:      default y
+//config:      select SHELL_HUSH
+//config:      help
+//config:      hush is a small shell. It handles the normal flow control
+//config:      constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
+//config:      case/esac. Redirections, here documents, $((arithmetic))
+//config:      and functions are supported.
+//config:
+//config:      It will compile and work on no-mmu systems.
+//config:
+//config:      It does not handle select, aliases, tilde expansion,
+//config:      &>file and >&file redirection of stdout+stderr.
+//config:
+// This option is visible (has a description) to make it possible to select
+// a "scripted" applet (such as NOLOGIN) but avoid selecting any shells:
+//config:config SHELL_HUSH
+//config:      bool "Internal shell for embedded script support"
+//config:      default n
+//config:
+//config:# hush options
+//config:# It's only needed to get "nice" menuconfig indenting.
+//config:if SHELL_HUSH || HUSH || SH_IS_HUSH || BASH_IS_HUSH
+//config:
+//config:config HUSH_BASH_COMPAT
+//config:      bool "bash-compatible extensions"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_BRACE_EXPANSION
+//config:      bool "Brace expansion"
+//config:      default y
+//config:      depends on HUSH_BASH_COMPAT
+//config:      help
+//config:      Enable {abc,def} extension.
+//config:
+//config:config HUSH_BASH_SOURCE_CURDIR
+//config:      bool "'source' and '.' builtins search current directory after $PATH"
+//config:      default n   # do not encourage non-standard behavior
+//config:      depends on HUSH_BASH_COMPAT
+//config:      help
+//config:      This is not compliant with standards. Avoid if possible.
+//config:
+//config:config HUSH_LINENO_VAR
+//config:      bool "$LINENO variable (bashism)"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_INTERACTIVE
+//config:      bool "Interactive mode"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:      help
+//config:      Enable interactive mode (prompt and command editing).
+//config:      Without this, hush simply reads and executes commands
+//config:      from stdin just like a shell script from a file.
+//config:      No prompt, no PS1/PS2 magic shell variables.
+//config:
+//config:config HUSH_SAVEHISTORY
+//config:      bool "Save command history to .hush_history"
+//config:      default y
+//config:      depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
+//config:
+//config:config HUSH_JOB
+//config:      bool "Job control"
+//config:      default y
+//config:      depends on HUSH_INTERACTIVE
+//config:      help
+//config:      Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
+//config:      command (not entire shell), fg/bg builtins work. Without this option,
+//config:      "cmd &" still works by simply spawning a process and immediately
+//config:      prompting for next command (or executing next command in a script),
+//config:      but no separate process group is formed.
+//config:
+//config:config HUSH_TICK
+//config:      bool "Support command substitution"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:      help
+//config:      Enable `command` and $(command).
+//config:
+//config:config HUSH_IF
+//config:      bool "Support if/then/elif/else/fi"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_LOOPS
+//config:      bool "Support for, while and until loops"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_CASE
+//config:      bool "Support case ... esac statement"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:      help
+//config:      Enable case ... esac statement. +400 bytes.
+//config:
+//config:config HUSH_FUNCTIONS
+//config:      bool "Support funcname() { commands; } syntax"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:      help
+//config:      Enable support for shell functions. +800 bytes.
+//config:
+//config:config HUSH_LOCAL
+//config:      bool "local builtin"
+//config:      default y
+//config:      depends on HUSH_FUNCTIONS
+//config:      help
+//config:      Enable support for local variables in functions.
+//config:
+//config:config HUSH_RANDOM_SUPPORT
+//config:      bool "Pseudorandom generator and $RANDOM variable"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:      help
+//config:      Enable pseudorandom generator and dynamic variable "$RANDOM".
+//config:      Each read of "$RANDOM" will generate a new pseudorandom value.
+//config:
+//config:config HUSH_MODE_X
+//config:      bool "Support 'hush -x' option and 'set -x' command"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:      help
+//config:      This instructs hush to print commands before execution.
+//config:      Adds ~300 bytes.
+//config:
+//config:config HUSH_ECHO
+//config:      bool "echo builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_PRINTF
+//config:      bool "printf builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_TEST
+//config:      bool "test builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_HELP
+//config:      bool "help builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_EXPORT
+//config:      bool "export builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_EXPORT_N
+//config:      bool "Support 'export -n' option"
+//config:      default y
+//config:      depends on HUSH_EXPORT
+//config:      help
+//config:      export -n unexports variables. It is a bash extension.
+//config:
+//config:config HUSH_READONLY
+//config:      bool "readonly builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:      help
+//config:      Enable support for read-only variables.
+//config:
+//config:config HUSH_KILL
+//config:      bool "kill builtin (supports kill %jobspec)"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_WAIT
+//config:      bool "wait builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_COMMAND
+//config:      bool "command builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_TRAP
+//config:      bool "trap builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_TYPE
+//config:      bool "type builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_TIMES
+//config:      bool "times builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_READ
+//config:      bool "read builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_SET
+//config:      bool "set builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_UNSET
+//config:      bool "unset builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_ULIMIT
+//config:      bool "ulimit builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_UMASK
+//config:      bool "umask builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_GETOPTS
+//config:      bool "getopts builtin"
+//config:      default y
+//config:      depends on SHELL_HUSH
+//config:
+//config:config HUSH_MEMLEAK
+//config:      bool "memleak builtin (debugging)"
+//config:      default n
+//config:      depends on SHELL_HUSH
+//config:
+//config:endif # hush options
+
+//applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
+//                       APPLET_ODDNAME:name  main  location    suid_type     help
+//applet:IF_SH_IS_HUSH(  APPLET_ODDNAME(sh,   hush, BB_DIR_BIN, BB_SUID_DROP, hush))
+//applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
+
+//kbuild:lib-$(CONFIG_SHELL_HUSH) += hush.o match.o shell_common.o
+//kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
+
+/* -i (interactive) is also accepted,
+ * but does nothing, therefore not shown in help.
+ * NOMMU-specific options are not meant to be used by users,
+ * therefore we don't show them either.
+ */
+//usage:#define hush_trivial_usage
+//usage:       "[-enxl] [-c 'SCRIPT' [ARG0 ARGS] | FILE [ARGS] | -s [ARGS]]"
+//usage:#define hush_full_usage "\n\n"
+//usage:       "Unix shell interpreter"
+
+#if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
+       || defined(__APPLE__) \
+    )
+# include <malloc.h>   /* for malloc_trim */
+#endif
+#include <glob.h>
+/* #include <dmalloc.h> */
+#if ENABLE_HUSH_CASE
+# include <fnmatch.h>
+#endif
+#include <sys/times.h>
+#include <sys/utsname.h> /* for setting $HOSTNAME */
+
+#include "busybox.h"  /* for APPLET_IS_NOFORK/NOEXEC */
+#include "unicode.h"
+#include "shell_common.h"
+#include "math.h"
+#include "match.h"
+#if ENABLE_HUSH_RANDOM_SUPPORT
+# include "random.h"
+#else
+# define CLEAR_RANDOM_T(rnd) ((void)0)
+#endif
+#ifndef O_CLOEXEC
+# define O_CLOEXEC 0
+#endif
+#ifndef F_DUPFD_CLOEXEC
+# define F_DUPFD_CLOEXEC F_DUPFD
+#endif
+
+#if ENABLE_FEATURE_SH_EMBEDDED_SCRIPTS && !(ENABLE_ASH || ENABLE_SH_IS_ASH || ENABLE_BASH_IS_ASH)
+# include "embedded_scripts.h"
+#else
+# define NUM_SCRIPTS 0
+#endif
+
+/* So far, all bash compat is controlled by one config option */
+/* Separate defines document which part of code implements what */
+#define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT
+#define BASH_SUBSTR        ENABLE_HUSH_BASH_COMPAT
+#define BASH_SOURCE        ENABLE_HUSH_BASH_COMPAT
+#define BASH_DOLLAR_SQUOTE ENABLE_HUSH_BASH_COMPAT
+#define BASH_HOSTNAME_VAR  ENABLE_HUSH_BASH_COMPAT
+#define BASH_EPOCH_VARS    ENABLE_HUSH_BASH_COMPAT
+#define BASH_TEST2         (ENABLE_HUSH_BASH_COMPAT && ENABLE_HUSH_TEST)
+#define BASH_READ_D        ENABLE_HUSH_BASH_COMPAT
+
+
+/* Build knobs */
+#define LEAK_HUNTING 0
+#define BUILD_AS_NOMMU 0
+/* Enable/disable sanity checks. Ok to enable in production,
+ * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
+ * Keeping 1 for now even in released versions.
+ */
+#define HUSH_DEBUG 1
+/* Slightly bigger (+200 bytes), but faster hush.
+ * So far it only enables a trick with counting SIGCHLDs and forks,
+ * which allows us to do fewer waitpid's.
+ * (we can detect a case where neither forks were done nor SIGCHLDs happened
+ * and therefore waitpid will return the same result as last time)
+ */
+#define ENABLE_HUSH_FAST 0
+/* TODO: implement simplified code for users which do not need ${var%...} ops
+ * So far ${var%...} ops are always enabled:
+ */
+#define ENABLE_HUSH_DOLLAR_OPS 1
+
+
+#if BUILD_AS_NOMMU
+# undef BB_MMU
+# undef USE_FOR_NOMMU
+# undef USE_FOR_MMU
+# define BB_MMU 0
+# define USE_FOR_NOMMU(...) __VA_ARGS__
+# define USE_FOR_MMU(...)
+#endif
+
+#include "NUM_APPLETS.h"
+#if NUM_APPLETS == 1
+/* STANDALONE does not make sense, and won't compile */
+# undef CONFIG_FEATURE_SH_STANDALONE
+# undef ENABLE_FEATURE_SH_STANDALONE
+# undef IF_FEATURE_SH_STANDALONE
+# undef IF_NOT_FEATURE_SH_STANDALONE
+# define ENABLE_FEATURE_SH_STANDALONE 0
+# define IF_FEATURE_SH_STANDALONE(...)
+# define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
+#endif
+
+#if !ENABLE_HUSH_INTERACTIVE
+# undef ENABLE_FEATURE_EDITING
+# define ENABLE_FEATURE_EDITING 0
+# undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
+# define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
+# undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
+# define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
+#endif
+
+/* Do we support ANY keywords? */
+#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
+# define HAS_KEYWORDS 1
+# define IF_HAS_KEYWORDS(...) __VA_ARGS__
+# define IF_HAS_NO_KEYWORDS(...)
+#else
+# define HAS_KEYWORDS 0
+# define IF_HAS_KEYWORDS(...)
+# define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
+#endif
+
+/* If you comment out one of these below, it will be #defined later
+ * to perform debug printfs to stderr: */
+#define debug_printf(...)         do {} while (0)
+/* Finer-grained debug switches */
+#define debug_printf_parse(...)   do {} while (0)
+#define debug_printf_heredoc(...) do {} while (0)
+#define debug_print_tree(a, b)    do {} while (0)
+#define debug_printf_exec(...)    do {} while (0)
+#define debug_printf_env(...)     do {} while (0)
+#define debug_printf_jobs(...)    do {} while (0)
+#define debug_printf_expand(...)  do {} while (0)
+#define debug_printf_varexp(...)  do {} while (0)
+#define debug_printf_glob(...)    do {} while (0)
+#define debug_printf_redir(...)   do {} while (0)
+#define debug_printf_list(...)    do {} while (0)
+#define debug_printf_subst(...)   do {} while (0)
+#define debug_printf_prompt(...)  do {} while (0)
+#define debug_printf_clean(...)   do {} while (0)
+
+#define ERR_PTR ((void*)(long)1)
+
+#define JOB_STATUS_FORMAT    "[%u] %-22s %.40s\n"
+
+#define _SPECIAL_VARS_STR     "_*@$!?#-"
+#define SPECIAL_VARS_STR     ("_*@$!?#-" + 1)
+#define NUMERIC_SPECVARS_STR ("_*@$!?#-" + 3)
+#if BASH_PATTERN_SUBST
+/* Support / and // replace ops */
+/* Note that // is stored as \ in "encoded" string representation */
+# define VAR_ENCODED_SUBST_OPS      "\\/%#:-=+?"
+# define VAR_SUBST_OPS             ("\\/%#:-=+?" + 1)
+# define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
+#else
+# define VAR_ENCODED_SUBST_OPS      "%#:-=+?"
+# define VAR_SUBST_OPS              "%#:-=+?"
+# define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
+#endif
+
+#define SPECIAL_VAR_SYMBOL_STR "\3"
+#define SPECIAL_VAR_SYMBOL       3
+/* The "variable" with name "\1" emits string "\3". Testcase: "echo ^C" */
+#define SPECIAL_VAR_QUOTED_SVS   1
+
+struct variable;
+
+static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
+
+/* This supports saving pointers malloced in vfork child,
+ * to be freed in the parent.
+ */
+#if !BB_MMU
+typedef struct nommu_save_t {
+       struct variable *old_vars;
+       char **argv;
+       char **argv_from_re_execing;
+} nommu_save_t;
+#endif
+
+enum {
+       RES_NONE  = 0,
+#if ENABLE_HUSH_IF
+       RES_IF    ,
+       RES_THEN  ,
+       RES_ELIF  ,
+       RES_ELSE  ,
+       RES_FI    ,
+#endif
+#if ENABLE_HUSH_LOOPS
+       RES_FOR   ,
+       RES_WHILE ,
+       RES_UNTIL ,
+       RES_DO    ,
+       RES_DONE  ,
+#endif
+#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
+       RES_IN    ,
+#endif
+#if ENABLE_HUSH_CASE
+       RES_CASE  ,
+       /* three pseudo-keywords support contrived "case" syntax: */
+       RES_CASE_IN,   /* "case ... IN", turns into RES_MATCH when IN is observed */
+       RES_MATCH ,    /* "word)" */
+       RES_CASE_BODY, /* "this command is inside CASE" */
+       RES_ESAC  ,
+#endif
+       RES_XXXX  ,
+       RES_SNTX
+};
+
+typedef struct o_string {
+       char *data;
+       int length; /* position where data is appended */
+       int maxlen;
+       int o_expflags;
+       /* At least some part of the string was inside '' or "",
+        * possibly empty one: word"", wo''rd etc. */
+       smallint has_quoted_part;
+       smallint has_empty_slot;
+       smallint ended_in_ifs;
+} o_string;
+enum {
+       EXP_FLAG_SINGLEWORD     = 0x80, /* must be 0x80 */
+       EXP_FLAG_GLOB           = 0x2,
+       /* Protect newly added chars against globbing
+        * by prepending \ to *, ?, [, \ */
+       EXP_FLAG_ESC_GLOB_CHARS = 0x1,
+};
+/* Used for initialization: o_string foo = NULL_O_STRING; */
+#define NULL_O_STRING { NULL }
+
+#ifndef debug_printf_parse
+static const char *const assignment_flag[] = {
+       "MAYBE_ASSIGNMENT",
+       "DEFINITELY_ASSIGNMENT",
+       "NOT_ASSIGNMENT",
+       "WORD_IS_KEYWORD",
+};
+#endif
+
+/* We almost can use standard FILE api, but we need an ability to move
+ * its fd when redirects coincide with it. No api exists for that
+ * (RFE for it at https://sourceware.org/bugzilla/show_bug.cgi?id=21902).
+ * HFILE is our internal alternative. Only supports reading.
+ * Since we now can, we incorporate linked list of all opened HFILEs
+ * into the struct (used to be a separate mini-list).
+ */
+typedef struct HFILE {
+       char *cur;
+       char *end;
+       struct HFILE *next_hfile;
+       int fd;
+       char buf[1024];
+} HFILE;
+
+typedef struct in_str {
+       const char *p;
+       int peek_buf[2];
+       int last_char;
+       HFILE *file;
+} in_str;
+
+/* The descrip member of this structure is only used to make
+ * debugging output pretty */
+static const struct {
+       int32_t mode;
+       signed char default_fd;
+       char descrip[3];
+} redir_table[] ALIGN4 = {
+       { O_RDONLY,                  0, "<"  },
+       { O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
+       { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
+       { O_CREAT|O_RDWR,            1, "<>" },
+       { O_RDONLY,                  0, "<<" },
+/* Should not be needed. Bogus default_fd helps in debugging */
+/*     { O_RDONLY,                 77, "<<" }, */
+};
+
+struct redir_struct {
+       struct redir_struct *next;
+       char *rd_filename;          /* filename */
+       int rd_fd;                  /* fd to redirect */
+       /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
+       int rd_dup;
+       smallint rd_type;           /* (enum redir_type) */
+       /* note: for heredocs, rd_filename contains heredoc delimiter,
+        * and subsequently heredoc itself; and rd_dup is a bitmask:
+        * bit 0: do we need to trim leading tabs?
+        * bit 1: is heredoc quoted (<<'delim' syntax) ?
+        */
+};
+typedef enum redir_type {
+       REDIRECT_INPUT     = 0,
+       REDIRECT_OVERWRITE = 1,
+       REDIRECT_APPEND    = 2,
+       REDIRECT_IO        = 3,
+       REDIRECT_HEREDOC   = 4,
+       REDIRECT_HEREDOC2  = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
+
+       REDIRFD_CLOSE      = -3,
+       REDIRFD_SYNTAX_ERR = -2,
+       REDIRFD_TO_FILE    = -1,
+       /* otherwise, rd_fd is redirected to rd_dup */
+
+       HEREDOC_SKIPTABS = 1,
+       HEREDOC_QUOTED   = 2,
+} redir_type;
+
+
+struct command {
+       pid_t pid;                  /* 0 if exited */
+       unsigned assignment_cnt;    /* how many argv[i] are assignments? */
+#if ENABLE_HUSH_LINENO_VAR
+       unsigned lineno;
+#endif
+       smallint cmd_type;          /* CMD_xxx */
+#define CMD_NORMAL   0
+#define CMD_SUBSHELL 1
+#if BASH_TEST2
+/* used for "[[ EXPR ]]" */
+# define CMD_TEST2_SINGLEWORD_NOGLOB 2
+#endif
+#if BASH_TEST2 || ENABLE_HUSH_LOCAL || ENABLE_HUSH_EXPORT || ENABLE_HUSH_READONLY
+/* used to prevent word splitting and globbing in "export v=t*" */
+# define CMD_SINGLEWORD_NOGLOB 3
+#endif
+#if ENABLE_HUSH_FUNCTIONS
+# define CMD_FUNCDEF 4
+#endif
+
+       smalluint cmd_exitcode;
+       /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
+       struct pipe *group;
+#if !BB_MMU
+       char *group_as_string;
+#endif
+#if ENABLE_HUSH_FUNCTIONS
+       struct function *child_func;
+/* This field is used to prevent a bug here:
+ * while...do f1() {a;}; f1; f1() {b;}; f1; done
+ * When we execute "f1() {a;}" cmd, we create new function and clear
+ * cmd->group, cmd->group_as_string, cmd->argv[0].
+ * When we execute "f1() {b;}", we notice that f1 exists,
+ * and that its "parent cmd" struct is still "alive",
+ * we put those fields back into cmd->xxx
+ * (struct function has ->parent_cmd ptr to facilitate that).
+ * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
+ * Without this trick, loop would execute a;b;b;b;...
+ * instead of correct sequence a;b;a;b;...
+ * When command is freed, it severs the link
+ * (sets ->child_func->parent_cmd to NULL).
+ */
+#endif
+       char **argv;                /* command name and arguments */
+/* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
+ * and on execution these are substituted with their values.
+ * Substitution can make _several_ words out of one argv[n]!
+ * Example: argv[0]=='.^C*^C.' here: echo .$*.
+ * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
+ */
+       struct redir_struct *redirects; /* I/O redirections */
+};
+/* Is there anything in this command at all? */
+#define IS_NULL_CMD(cmd) \
+       (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
+
+struct pipe {
+       struct pipe *next;
+       int num_cmds;               /* total number of commands in pipe */
+       int alive_cmds;             /* number of commands running (not exited) */
+       int stopped_cmds;           /* number of commands alive, but stopped */
+#if ENABLE_HUSH_JOB
+       unsigned jobid;             /* job number */
+       pid_t pgrp;                 /* process group ID for the job */
+       char *cmdtext;              /* name of job */
+#endif
+       struct command *cmds;       /* array of commands in pipe */
+       smallint followup;          /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
+       IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
+       IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
+};
+typedef enum pipe_style {
+       PIPE_SEQ = 0,
+       PIPE_AND = 1,
+       PIPE_OR  = 2,
+       PIPE_BG  = 3,
+} pipe_style;
+/* Is there anything in this pipe at all? */
+#define IS_NULL_PIPE(pi) \
+       ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
+
+/* This holds pointers to the various results of parsing */
+struct parse_context {
+       /* linked list of pipes */
+       struct pipe *list_head;
+       /* last pipe (being constructed right now) */
+       struct pipe *pipe;
+       /* last command in pipe (being constructed right now) */
+       struct command *command;
+       /* last redirect in command->redirects list */
+       struct redir_struct *pending_redirect;
+       o_string word;
+#if !BB_MMU
+       o_string as_string;
+#endif
+       smallint is_assignment; /* 0:maybe, 1:yes, 2:no, 3:keyword */
+#if HAS_KEYWORDS
+       smallint ctx_res_w;
+       smallint ctx_inverted; /* "! cmd | cmd" */
+#if ENABLE_HUSH_CASE
+       smallint ctx_dsemicolon; /* ";;" seen */
+#endif
+       /* bitmask of FLAG_xxx, for figuring out valid reserved words */
+       int old_flag;
+       /* group we are enclosed in:
+        * example: "if pipe1; pipe2; then pipe3; fi"
+        * when we see "if" or "then", we malloc and copy current context,
+        * and make ->stack point to it. then we parse pipeN.
+        * when closing "then" / fi" / whatever is found,
+        * we move list_head into ->stack->command->group,
+        * copy ->stack into current context, and delete ->stack.
+        * (parsing of { list } and ( list ) doesn't use this method)
+        */
+       struct parse_context *stack;
+#endif
+};
+enum {
+       MAYBE_ASSIGNMENT      = 0,
+       DEFINITELY_ASSIGNMENT = 1,
+       NOT_ASSIGNMENT        = 2,
+       /* Not an assignment, but next word may be: "if v=xyz cmd;" */
+       WORD_IS_KEYWORD       = 3,
+};
+
+/* On program start, environ points to initial environment.
+ * putenv adds new pointers into it, unsetenv removes them.
+ * Neither of these (de)allocates the strings.
+ * setenv allocates new strings in malloc space and does putenv,
+ * and thus setenv is unusable (leaky) for shell's purposes */
+#define setenv(...) setenv_is_leaky_dont_use()
+struct variable {
+       struct variable *next;
+       char *varstr;        /* points to "name=" portion */
+       int max_len;         /* if > 0, name is part of initial env; else name is malloced */
+       uint16_t var_nest_level;
+       smallint flg_export; /* putenv should be done on this var */
+       smallint flg_read_only;
+};
+
+enum {
+       BC_BREAK = 1,
+       BC_CONTINUE = 2,
+};
+
+#if ENABLE_HUSH_FUNCTIONS
+struct function {
+       struct function *next;
+       char *name;
+       struct command *parent_cmd;
+       struct pipe *body;
+# if !BB_MMU
+       char *body_as_string;
+# endif
+};
+#endif
+
+
+/* set -/+o OPT support. (TODO: make it optional)
+ * bash supports the following opts:
+ * allexport       off
+ * braceexpand     on
+ * emacs           on
+ * errexit         off
+ * errtrace        off
+ * functrace       off
+ * hashall         on
+ * histexpand      off
+ * history         on
+ * ignoreeof       off
+ * interactive-comments    on
+ * keyword         off
+ * monitor         on
+ * noclobber       off
+ * noexec          off
+ * noglob          off
+ * nolog           off
+ * notify          off
+ * nounset         off
+ * onecmd          off
+ * physical        off
+ * pipefail        off
+ * posix           off
+ * privileged      off
+ * verbose         off
+ * vi              off
+ * xtrace          off
+ */
+static const char o_opt_strings[] ALIGN1 =
+       "pipefail\0"
+       "noexec\0"
+       "errexit\0"
+#if ENABLE_HUSH_MODE_X
+       "xtrace\0"
+#endif
+       ;
+enum {
+       OPT_O_PIPEFAIL,
+       OPT_O_NOEXEC,
+       OPT_O_ERREXIT,
+#if ENABLE_HUSH_MODE_X
+       OPT_O_XTRACE,
+#endif
+       NUM_OPT_O
+};
+
+/* "Globals" within this file */
+/* Sorted roughly by size (smaller offsets == smaller code) */
+struct globals {
+       /* interactive_fd != 0 means we are an interactive shell.
+        * If we are, then saved_tty_pgrp can also be != 0, meaning
+        * that controlling tty is available. With saved_tty_pgrp == 0,
+        * job control still works, but terminal signals
+        * (^C, ^Z, ^Y, ^\) won't work at all, and background
+        * process groups can only be created with "cmd &".
+        * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
+        * to give tty to the foreground process group,
+        * and will take it back when the group is stopped (^Z)
+        * or killed (^C).
+        */
+#if ENABLE_HUSH_INTERACTIVE
+       /* 'interactive_fd' is a fd# open to ctty, if we have one
+        * _AND_ if we decided to act interactively */
+       int interactive_fd;
+       IF_NOT_FEATURE_EDITING_FANCY_PROMPT(char *PS1;)
+# define G_interactive_fd (G.interactive_fd)
+#else
+# define G_interactive_fd 0
+#endif
+#if ENABLE_FEATURE_EDITING
+       line_input_t *line_input_state;
+#endif
+       pid_t root_pid;
+       pid_t root_ppid;
+       pid_t last_bg_pid;
+#if ENABLE_HUSH_RANDOM_SUPPORT
+       random_t random_gen;
+#endif
+#if ENABLE_HUSH_JOB
+       int run_list_level;
+       unsigned last_jobid;
+       pid_t saved_tty_pgrp;
+       struct pipe *job_list;
+# define G_saved_tty_pgrp (G.saved_tty_pgrp)
+#else
+# define G_saved_tty_pgrp 0
+#endif
+       /* How deeply are we in context where "set -e" is ignored */
+       int errexit_depth;
+       /* "set -e" rules (do we follow them correctly?):
+        * Exit if pipe, list, or compound command exits with a non-zero status.
+        * Shell does not exit if failed command is part of condition in
+        * if/while, part of && or || list except the last command, any command
+        * in a pipe but the last, or if the command's return value is being
+        * inverted with !. If a compound command other than a subshell returns a
+        * non-zero status because a command failed while -e was being ignored, the
+        * shell does not exit. A trap on ERR, if set, is executed before the shell
+        * exits [ERR is a bashism].
+        *
+        * If a compound command or function executes in a context where -e is
+        * ignored, none of the commands executed within are affected by the -e
+        * setting. If a compound command or function sets -e while executing in a
+        * context where -e is ignored, that setting does not have any effect until
+        * the compound command or the command containing the function call completes.
+        */
+
+       char o_opt[NUM_OPT_O];
+#if ENABLE_HUSH_MODE_X
+# define G_x_mode (G.o_opt[OPT_O_XTRACE])
+#else
+# define G_x_mode 0
+#endif
+       char opt_s;
+       char opt_c;
+#if ENABLE_HUSH_INTERACTIVE
+       smallint promptmode; /* 0: PS1, 1: PS2 */
+#endif
+       smallint flag_SIGINT;
+#if ENABLE_HUSH_LOOPS
+       smallint flag_break_continue;
+#endif
+#if ENABLE_HUSH_FUNCTIONS
+       /* 0: outside of a function (or sourced file)
+        * -1: inside of a function, ok to use return builtin
+        * 1: return is invoked, skip all till end of func
+        */
+       smallint flag_return_in_progress;
+# define G_flag_return_in_progress (G.flag_return_in_progress)
+#else
+# define G_flag_return_in_progress 0
+#endif
+       smallint exiting; /* used to prevent EXIT trap recursion */
+       /* These support $? */
+       smalluint last_exitcode;
+       smalluint expand_exitcode;
+       smalluint last_bg_pid_exitcode;
+#if ENABLE_HUSH_SET
+       /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
+       smalluint global_args_malloced;
+# define G_global_args_malloced (G.global_args_malloced)
+#else
+# define G_global_args_malloced 0
+#endif
+#if ENABLE_HUSH_BASH_COMPAT
+       int dead_job_exitcode; /* for "wait -n" */
+#endif
+       /* how many non-NULL argv's we have. NB: $# + 1 */
+       int global_argc;
+       char **global_argv;
+#if !BB_MMU
+       char *argv0_for_re_execing;
+#endif
+#if ENABLE_HUSH_LOOPS
+       unsigned depth_break_continue;
+       unsigned depth_of_loop;
+#endif
+#if ENABLE_HUSH_GETOPTS
+       unsigned getopt_count;
+#endif
+       const char *ifs;
+       char *ifs_whitespace; /* = G.ifs or malloced */
+       const char *cwd;
+       struct variable *top_var;
+       char **expanded_assignments;
+       struct variable **shadowed_vars_pp;
+       unsigned var_nest_level;
+#if ENABLE_HUSH_FUNCTIONS
+# if ENABLE_HUSH_LOCAL
+       unsigned func_nest_level; /* solely to prevent "local v" in non-functions */
+# endif
+       struct function *top_func;
+#endif
+       /* Signal and trap handling */
+#if ENABLE_HUSH_FAST
+       unsigned count_SIGCHLD;
+       unsigned handled_SIGCHLD;
+       smallint we_have_children;
+#endif
+#if ENABLE_HUSH_LINENO_VAR
+       unsigned parse_lineno;
+       unsigned execute_lineno;
+#endif
+       HFILE *HFILE_list;
+       HFILE *HFILE_stdin;
+       /* Which signals have non-DFL handler (even with no traps set)?
+        * Set at the start to:
+        * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
+        * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
+        * The rest is cleared right before execv syscalls.
+        * Other than these two times, never modified.
+        */
+       unsigned special_sig_mask;
+#if ENABLE_HUSH_JOB
+       unsigned fatal_sig_mask;
+# define G_fatal_sig_mask (G.fatal_sig_mask)
+#else
+# define G_fatal_sig_mask 0
+#endif
+#if ENABLE_HUSH_TRAP
+       int pre_trap_exitcode;
+# if ENABLE_HUSH_FUNCTIONS
+       int return_exitcode;
+# endif
+       char **traps; /* char *traps[NSIG] */
+# define G_traps G.traps
+#else
+# define G_traps ((char**)NULL)
+#endif
+       sigset_t pending_set;
+#if ENABLE_HUSH_MEMLEAK
+       unsigned long memleak_value;
+#endif
+#if ENABLE_HUSH_MODE_X
+       unsigned x_mode_depth;
+       /* "set -x" output should not be redirectable with subsequent 2>FILE.
+        * We dup fd#2 to x_mode_fd when "set -x" is executed, and use it
+        * for all subsequent output.
+        */
+       int x_mode_fd;
+       o_string x_mode_buf;
+#endif
+#if HUSH_DEBUG >= 2
+       int debug_indent;
+#endif
+       struct sigaction sa;
+       char optstring_buf[sizeof("eixcs")];
+#if BASH_EPOCH_VARS
+       char epoch_buf[sizeof("%llu.nnnnnn") + sizeof(long long)*3];
+#endif
+#if ENABLE_FEATURE_EDITING
+       char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
+#endif
+};
+#define G (*ptr_to_globals)
+/* Not #defining name to G.name - this quickly gets unwieldy
+ * (too many defines). Also, I actually prefer to see when a variable
+ * is global, thus "G." prefix is a useful hint */
+#define INIT_G() do { \
+       SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
+       /* memset(&G.sa, 0, sizeof(G.sa)); */  \
+       sigfillset(&G.sa.sa_mask); \
+       G.sa.sa_flags = SA_RESTART; \
+} while (0)
+
+
+/* Function prototypes for builtins */
+static int builtin_cd(char **argv) FAST_FUNC;
+#if ENABLE_HUSH_ECHO
+static int builtin_echo(char **argv) FAST_FUNC;
+#endif
+static int builtin_eval(char **argv) FAST_FUNC;
+static int builtin_exec(char **argv) FAST_FUNC;
+static int builtin_exit(char **argv) FAST_FUNC;
+#if ENABLE_HUSH_EXPORT
+static int builtin_export(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_READONLY
+static int builtin_readonly(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_JOB
+static int builtin_fg_bg(char **argv) FAST_FUNC;
+static int builtin_jobs(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_GETOPTS
+static int builtin_getopts(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_HELP
+static int builtin_help(char **argv) FAST_FUNC;
+#endif
+#if MAX_HISTORY && ENABLE_FEATURE_EDITING
+static int builtin_history(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_LOCAL
+static int builtin_local(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_MEMLEAK
+static int builtin_memleak(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_PRINTF
+static int builtin_printf(char **argv) FAST_FUNC;
+#endif
+static int builtin_pwd(char **argv) FAST_FUNC;
+#if ENABLE_HUSH_READ
+static int builtin_read(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_SET
+static int builtin_set(char **argv) FAST_FUNC;
+#endif
+static int builtin_shift(char **argv) FAST_FUNC;
+static int builtin_source(char **argv) FAST_FUNC;
+#if ENABLE_HUSH_TEST || BASH_TEST2
+static int builtin_test(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_TRAP
+static int builtin_trap(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_TYPE
+static int builtin_type(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_TIMES
+static int builtin_times(char **argv) FAST_FUNC;
+#endif
+static int builtin_true(char **argv) FAST_FUNC;
+#if ENABLE_HUSH_UMASK
+static int builtin_umask(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_UNSET
+static int builtin_unset(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_KILL
+static int builtin_kill(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_WAIT
+static int builtin_wait(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_LOOPS
+static int builtin_break(char **argv) FAST_FUNC;
+static int builtin_continue(char **argv) FAST_FUNC;
+#endif
+#if ENABLE_HUSH_FUNCTIONS
+static int builtin_return(char **argv) FAST_FUNC;
+#endif
+
+/* Table of built-in functions.  They can be forked or not, depending on
+ * context: within pipes, they fork.  As simple commands, they do not.
+ * When used in non-forking context, they can change global variables
+ * in the parent shell process.  If forked, of course they cannot.
+ * For example, 'unset foo | whatever' will parse and run, but foo will
+ * still be set at the end. */
+struct built_in_command {
+       const char *b_cmd;
+       int (*b_function)(char **argv) FAST_FUNC;
+#if ENABLE_HUSH_HELP
+       const char *b_descr;
+# define BLTIN(cmd, func, help) { cmd, func, help }
+#else
+# define BLTIN(cmd, func, help) { cmd, func }
+#endif
+};
+
+static const struct built_in_command bltins1[] ALIGN_PTR = {
+       BLTIN("."        , builtin_source  , "Run commands in file"),
+       BLTIN(":"        , builtin_true    , NULL),
+#if ENABLE_HUSH_JOB
+       BLTIN("bg"       , builtin_fg_bg   , "Resume job in background"),
+#endif
+#if ENABLE_HUSH_LOOPS
+       BLTIN("break"    , builtin_break   , "Exit loop"),
+#endif
+       BLTIN("cd"       , builtin_cd      , "Change directory"),
+#if ENABLE_HUSH_LOOPS
+       BLTIN("continue" , builtin_continue, "Start new loop iteration"),
+#endif
+       BLTIN("eval"     , builtin_eval    , "Construct and run shell command"),
+       BLTIN("exec"     , builtin_exec    , "Execute command, don't return to shell"),
+       BLTIN("exit"     , builtin_exit    , NULL),
+#if ENABLE_HUSH_EXPORT
+       BLTIN("export"   , builtin_export  , "Set environment variables"),
+#endif
+#if ENABLE_HUSH_JOB
+       BLTIN("fg"       , builtin_fg_bg   , "Bring job to foreground"),
+#endif
+#if ENABLE_HUSH_GETOPTS
+       BLTIN("getopts"  , builtin_getopts , NULL),
+#endif
+#if ENABLE_HUSH_HELP
+       BLTIN("help"     , builtin_help    , NULL),
+#endif
+#if MAX_HISTORY && ENABLE_FEATURE_EDITING
+       BLTIN("history"  , builtin_history , "Show history"),
+#endif
+#if ENABLE_HUSH_JOB
+       BLTIN("jobs"     , builtin_jobs    , "List jobs"),
+#endif
+#if ENABLE_HUSH_KILL
+       BLTIN("kill"     , builtin_kill    , "Send signals to processes"),
+#endif
+#if ENABLE_HUSH_LOCAL
+       BLTIN("local"    , builtin_local   , "Set local variables"),
+#endif
+#if ENABLE_HUSH_MEMLEAK
+       BLTIN("memleak"  , builtin_memleak , NULL),
+#endif
+#if ENABLE_HUSH_READ
+       BLTIN("read"     , builtin_read    , "Input into variable"),
+#endif
+#if ENABLE_HUSH_READONLY
+       BLTIN("readonly" , builtin_readonly, "Make variables read-only"),
+#endif
+#if ENABLE_HUSH_FUNCTIONS
+       BLTIN("return"   , builtin_return  , "Return from function"),
+#endif
+#if ENABLE_HUSH_SET
+       BLTIN("set"      , builtin_set     , "Set positional parameters"),
+#endif
+       BLTIN("shift"    , builtin_shift   , "Shift positional parameters"),
+#if BASH_SOURCE
+       BLTIN("source"   , builtin_source  , NULL),
+#endif
+#if ENABLE_HUSH_TIMES
+       BLTIN("times"    , builtin_times   , NULL),
+#endif
+#if ENABLE_HUSH_TRAP
+       BLTIN("trap"     , builtin_trap    , "Trap signals"),
+#endif
+       BLTIN("true"     , builtin_true    , NULL),
+#if ENABLE_HUSH_TYPE
+       BLTIN("type"     , builtin_type    , "Show command type"),
+#endif
+#if ENABLE_HUSH_ULIMIT
+       BLTIN("ulimit"   , shell_builtin_ulimit, "Control resource limits"),
+#endif
+#if ENABLE_HUSH_UMASK
+       BLTIN("umask"    , builtin_umask   , "Set file creation mask"),
+#endif
+#if ENABLE_HUSH_UNSET
+       BLTIN("unset"    , builtin_unset   , "Unset variables"),
+#endif
+#if ENABLE_HUSH_WAIT
+       BLTIN("wait"     , builtin_wait    , "Wait for process to finish"),
+#endif
+};
+/* These builtins won't be used if we are on NOMMU and need to re-exec
+ * (it's cheaper to run an external program in this case):
+ */
+static const struct built_in_command bltins2[] ALIGN_PTR = {
+#if ENABLE_HUSH_TEST
+       BLTIN("["        , builtin_test    , NULL),
+#endif
+#if BASH_TEST2
+       BLTIN("[["       , builtin_test    , NULL),
+#endif
+#if ENABLE_HUSH_ECHO
+       BLTIN("echo"     , builtin_echo    , NULL),
+#endif
+#if ENABLE_HUSH_PRINTF
+       BLTIN("printf"   , builtin_printf  , NULL),
+#endif
+       BLTIN("pwd"      , builtin_pwd     , NULL),
+#if ENABLE_HUSH_TEST
+       BLTIN("test"     , builtin_test    , NULL),
+#endif
+};
+
+
+/* Debug printouts.
+ */
+#if HUSH_DEBUG >= 2
+/* prevent disasters with G.debug_indent < 0 */
+# define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
+# define debug_enter() (G.debug_indent++)
+# define debug_leave() (G.debug_indent--)
+#else
+# define indent()      ((void)0)
+# define debug_enter() ((void)0)
+# define debug_leave() ((void)0)
+#endif
+
+#ifndef debug_printf
+# define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
+#endif
+
+#ifndef debug_printf_parse
+# define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
+#endif
+
+#ifndef debug_printf_heredoc
+# define debug_printf_heredoc(...) (indent(), fdprintf(2, __VA_ARGS__))
+#endif
+
+#ifndef debug_printf_exec
+#define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
+#endif
+
+#ifndef debug_printf_env
+# define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
+#endif
+
+#ifndef debug_printf_jobs
+# define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
+# define DEBUG_JOBS 1
+#else
+# define DEBUG_JOBS 0
+#endif
+
+#ifndef debug_printf_expand
+# define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
+# define DEBUG_EXPAND 1
+#else
+# define DEBUG_EXPAND 0
+#endif
+
+#ifndef debug_printf_varexp
+# define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
+#endif
+
+#ifndef debug_printf_glob
+# define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
+# define DEBUG_GLOB 1
+#else
+# define DEBUG_GLOB 0
+#endif
+
+#ifndef debug_printf_redir
+# define debug_printf_redir(...) (indent(), fdprintf(2, __VA_ARGS__))
+#endif
+
+#ifndef debug_printf_list
+# define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
+#endif
+
+#ifndef debug_printf_subst
+# define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
+#endif
+
+#ifndef debug_printf_prompt
+# define debug_printf_prompt(...) (indent(), fdprintf(2, __VA_ARGS__))
+#endif
+
+#ifndef debug_printf_clean
+# define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
+# define DEBUG_CLEAN 1
+#else
+# define DEBUG_CLEAN 0
+#endif
+
+#if DEBUG_EXPAND
+static void debug_print_strings(const char *prefix, char **vv)
+{
+       indent();
+       fdprintf(2, "%s:\n", prefix);
+       while (*vv)
+               fdprintf(2, " '%s'\n", *vv++);
+}
+#else
+# define debug_print_strings(prefix, vv) ((void)0)
+#endif
+
+
+/* Leak hunting. Use hush_leaktool.sh for post-processing.
+ */
+#if LEAK_HUNTING
+static void *xxmalloc(int lineno, size_t size)
+{
+       void *ptr = xmalloc((size + 0xff) & ~0xff);
+       fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
+       return ptr;
+}
+static void *xxrealloc(int lineno, void *ptr, size_t size)
+{
+       ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
+       fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
+       return ptr;
+}
+static char *xxstrdup(int lineno, const char *str)
+{
+       char *ptr = xstrdup(str);
+       fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
+       return ptr;
+}
+static void xxfree(void *ptr)
+{
+       fdprintf(2, "free %p\n", ptr);
+       free(ptr);
+}
+# define xmalloc(s)     xxmalloc(__LINE__, s)
+# define xrealloc(p, s) xxrealloc(__LINE__, p, s)
+# define xstrdup(s)     xxstrdup(__LINE__, s)
+# define free(p)        xxfree(p)
+#endif
+
+
+/* Syntax and runtime errors. They always abort scripts.
+ * In interactive use they usually discard unparsed and/or unexecuted commands
+ * and return to the prompt.
+ * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
+ */
+#if HUSH_DEBUG < 2
+# define msg_and_die_if_script(lineno, ...)     msg_and_die_if_script(__VA_ARGS__)
+# define syntax_error(lineno, msg)              syntax_error(msg)
+# define syntax_error_at(lineno, msg)           syntax_error_at(msg)
+# define syntax_error_unterm_ch(lineno, ch)     syntax_error_unterm_ch(ch)
+# define syntax_error_unterm_str(lineno, s)     syntax_error_unterm_str(s)
+# define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
+#endif
+
+static void die_if_script(void)
+{
+       if (!G_interactive_fd) {
+               if (G.last_exitcode) /* sometines it's 2, not 1 (bash compat) */
+                       xfunc_error_retval = G.last_exitcode;
+               xfunc_die();
+       }
+}
+
+static void msg_and_die_if_script(unsigned lineno, const char *fmt, ...)
+{
+       va_list p;
+
+#if HUSH_DEBUG >= 2
+       bb_error_msg("hush.c:%u", lineno);
+#endif
+       va_start(p, fmt);
+       bb_verror_msg(fmt, p, NULL);
+       va_end(p);
+       die_if_script();
+}
+
+static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
+{
+       if (msg)
+               bb_error_msg("syntax error: %s", msg);
+       else
+               bb_simple_error_msg("syntax error");
+       die_if_script();
+}
+
+static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
+{
+       bb_error_msg("syntax error at '%s'", msg);
+       die_if_script();
+}
+
+static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
+{
+       bb_error_msg("syntax error: unterminated %s", s);
+//? source4.tests fails: in bash, echo ${^} in script does not terminate the script
+//     die_if_script();
+}
+
+static void syntax_error_unterm_ch(unsigned lineno, char ch)
+{
+       char msg[2] = { ch, '\0' };
+       syntax_error_unterm_str(lineno, msg);
+}
+
+static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
+{
+       char msg[2];
+       msg[0] = ch;
+       msg[1] = '\0';
+#if HUSH_DEBUG >= 2
+       bb_error_msg("hush.c:%u", lineno);
+#endif
+       bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
+       die_if_script();
+}
+
+#if HUSH_DEBUG < 2
+# undef msg_and_die_if_script
+# undef syntax_error
+# undef syntax_error_at
+# undef syntax_error_unterm_ch
+# undef syntax_error_unterm_str
+# undef syntax_error_unexpected_ch
+#else
+# define msg_and_die_if_script(...)     msg_and_die_if_script(__LINE__, __VA_ARGS__)
+# define syntax_error(msg)              syntax_error(__LINE__, msg)
+# define syntax_error_at(msg)           syntax_error_at(__LINE__, msg)
+# define syntax_error_unterm_ch(ch)     syntax_error_unterm_ch(__LINE__, ch)
+# define syntax_error_unterm_str(s)     syntax_error_unterm_str(__LINE__, s)
+# define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
+#endif
+
+
+/* Utility functions
+ */
+/* Replace each \x with x in place, return ptr past NUL. */
+static char *unbackslash(char *src)
+{
+       char *dst = src = strchrnul(src, '\\');
+       while (1) {
+               if (*src == '\\') {
+                       src++;
+                       if (*src != '\0') {
+                               /* \x -> x */
+                               *dst++ = *src++;
+                               continue;
+                       }
+                       /* else: "\<nul>". Do not delete this backslash.
+                        * Testcase: eval 'echo ok\'
+                        */
+                       *dst++ = '\\';
+                       /* fallthrough */
+               }
+               if ((*dst++ = *src++) == '\0')
+                       break;
+       }
+       return dst;
+}
+
+static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
+{
+       int i;
+       unsigned count1;
+       unsigned count2;
+       char **v;
+
+       v = strings;
+       count1 = 0;
+       if (v) {
+               while (*v) {
+                       count1++;
+                       v++;
+               }
+       }
+       count2 = 0;
+       v = add;
+       while (*v) {
+               count2++;
+               v++;
+       }
+       v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
+       v[count1 + count2] = NULL;
+       i = count2;
+       while (--i >= 0)
+               v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
+       return v;
+}
+#if LEAK_HUNTING
+static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
+{
+       char **ptr = add_strings_to_strings(strings, add, need_to_dup);
+       fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
+       return ptr;
+}
+#define add_strings_to_strings(strings, add, need_to_dup) \
+       xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
+#endif
+
+/* Note: takes ownership of "add" ptr (it is not strdup'ed) */
+static char **add_string_to_strings(char **strings, char *add)
+{
+       char *v[2];
+       v[0] = add;
+       v[1] = NULL;
+       return add_strings_to_strings(strings, v, /*dup:*/ 0);
+}
+#if LEAK_HUNTING
+static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
+{
+       char **ptr = add_string_to_strings(strings, add);
+       fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
+       return ptr;
+}
+#define add_string_to_strings(strings, add) \
+       xx_add_string_to_strings(__LINE__, strings, add)
+#endif
+
+static void free_strings(char **strings)
+{
+       char **v;
+
+       if (!strings)
+               return;
+       v = strings;
+       while (*v) {
+               free(*v);
+               v++;
+       }
+       free(strings);
+}
+
+static int dup_CLOEXEC(int fd, int avoid_fd)
+{
+       int newfd;
+ repeat:
+       newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1);
+       if (newfd >= 0) {
+               if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */
+                       fcntl(newfd, F_SETFD, FD_CLOEXEC);
+       } else { /* newfd < 0 */
+               if (errno == EBUSY)
+                       goto repeat;
+               if (errno == EINTR)
+                       goto repeat;
+       }
+       return newfd;
+}
+
+static int xdup_CLOEXEC_and_close(int fd, int avoid_fd)
+{
+       int newfd;
+ repeat:
+       newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1);
+       if (newfd < 0) {
+               if (errno == EBUSY)
+                       goto repeat;
+               if (errno == EINTR)
+                       goto repeat;
+               /* fd was not open? */
+               if (errno == EBADF)
+                       return fd;
+               xfunc_die();
+       }
+       if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */
+               fcntl(newfd, F_SETFD, FD_CLOEXEC);
+       close(fd);
+       return newfd;
+}
+
+
+/* Manipulating HFILEs */
+static HFILE *hfopen(const char *name)
+{
+       HFILE *fp;
+       int fd;
+
+       fd = STDIN_FILENO;
+       if (name) {
+               fd = open(name, O_RDONLY | O_CLOEXEC);
+               if (fd < 0)
+                       return NULL;
+               if (O_CLOEXEC == 0) /* ancient libc */
+                       close_on_exec_on(fd);
+       }
+
+       fp = xmalloc(sizeof(*fp));
+       if (name == NULL)
+               G.HFILE_stdin = fp;
+       fp->fd = fd;
+       fp->cur = fp->end = fp->buf;
+       fp->next_hfile = G.HFILE_list;
+       G.HFILE_list = fp;
+       return fp;
+}
+static void hfclose(HFILE *fp)
+{
+       HFILE **pp = &G.HFILE_list;
+       while (*pp) {
+               HFILE *cur = *pp;
+               if (cur == fp) {
+                       *pp = cur->next_hfile;
+                       break;
+               }
+               pp = &cur->next_hfile;
+       }
+       if (fp->fd >= 0)
+               close(fp->fd);
+       free(fp);
+}
+static int refill_HFILE_and_getc(HFILE *fp)
+{
+       int n;
+
+       if (fp->fd < 0) {
+               /* Already saw EOF */
+               return EOF;
+       }
+#if ENABLE_HUSH_INTERACTIVE && !ENABLE_FEATURE_EDITING
+       /* If user presses ^C, read() restarts after SIGINT (we use SA_RESTART).
+        * IOW: ^C will not immediately stop line input.
+        * But poll() is different: it does NOT restart after signals.
+        */
+       if (fp == G.HFILE_stdin) {
+               struct pollfd pfd[1];
+               pfd[0].fd = fp->fd;
+               pfd[0].events = POLLIN;
+               n = poll(pfd, 1, -1);
+               if (n < 0
+                /*&& errno == EINTR - assumed true */
+                && sigismember(&G.pending_set, SIGINT)
+               ) {
+                       return '\0';
+               }
+       }
+#else
+/* if FEATURE_EDITING=y, we do not use this routine for interactive input */
+#endif
+       /* Try to buffer more input */
+       n = safe_read(fp->fd, fp->buf, sizeof(fp->buf));
+       if (n < 0) {
+               bb_simple_perror_msg("read error");
+               n = 0;
+       }
+       fp->cur = fp->buf;
+       fp->end = fp->buf + n;
+       if (n == 0) {
+               /* EOF/error */
+               close(fp->fd);
+               fp->fd = -1;
+               return EOF;
+       }
+       return (unsigned char)(*fp->cur++);
+}
+/* Inlined for common case of non-empty buffer.
+ */
+static ALWAYS_INLINE int hfgetc(HFILE *fp)
+{
+       if (fp->cur < fp->end)
+               return (unsigned char)(*fp->cur++);
+       /* Buffer empty */
+       return refill_HFILE_and_getc(fp);
+}
+static int move_HFILEs_on_redirect(int fd, int avoid_fd)
+{
+       HFILE *fl = G.HFILE_list;
+       while (fl) {
+               if (fd == fl->fd) {
+                       /* We use it only on script files, they are all CLOEXEC */
+                       fl->fd = xdup_CLOEXEC_and_close(fd, avoid_fd);
+                       debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd);
+                       return 1; /* "found and moved" */
+               }
+               fl = fl->next_hfile;
+       }
+#if ENABLE_HUSH_MODE_X
+       if (G.x_mode_fd > 0 && fd == G.x_mode_fd) {
+               G.x_mode_fd = xdup_CLOEXEC_and_close(fd, avoid_fd);
+               return 1; /* "found and moved" */
+       }
+#endif
+       return 0; /* "not in the list" */
+}
+#if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
+static void close_all_HFILE_list(void)
+{
+       HFILE *fl = G.HFILE_list;
+       while (fl) {
+               /* hfclose would also free HFILE object.
+                * It is disastrous if we share memory with a vforked parent.
+                * I'm not sure we never come here after vfork.
+                * Therefore just close fd, nothing more.
+                *
+                * ">" instead of ">=": we don't close fd#0,
+                * interactive shell uses hfopen(NULL) as stdin input
+                * which has fl->fd == 0, but fd#0 gets redirected in pipes.
+                * If we'd close it here, then e.g. interactive "set | sort"
+                * with NOFORKed sort, would have sort's input fd closed.
+                */
+               if (fl->fd > 0)
+                       /*hfclose(fl); - unsafe */
+                       close(fl->fd);
+               fl = fl->next_hfile;
+       }
+}
+#endif
+static int fd_in_HFILEs(int fd)
+{
+       HFILE *fl = G.HFILE_list;
+       while (fl) {
+               if (fl->fd == fd)
+                       return 1;
+               fl = fl->next_hfile;
+       }
+       return 0;
+}
+
+
+/* Helpers for setting new $n and restoring them back
+ */
+typedef struct save_arg_t {
+       char *sv_argv0;
+       char **sv_g_argv;
+       int sv_g_argc;
+       IF_HUSH_SET(smallint sv_g_malloced;)
+} save_arg_t;
+
+static void save_and_replace_G_args(save_arg_t *sv, char **argv)
+{
+       sv->sv_argv0 = argv[0];
+       sv->sv_g_argv = G.global_argv;
+       sv->sv_g_argc = G.global_argc;
+       IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
+
+       argv[0] = G.global_argv[0]; /* retain $0 */
+       G.global_argv = argv;
+       IF_HUSH_SET(G.global_args_malloced = 0;)
+
+       G.global_argc = 1 + string_array_len(argv + 1);
+}
+
+static void restore_G_args(save_arg_t *sv, char **argv)
+{
+#if ENABLE_HUSH_SET
+       if (G.global_args_malloced) {
+               /* someone ran "set -- arg1 arg2 ...", undo */
+               char **pp = G.global_argv;
+               while (*++pp) /* note: does not free $0 */
+                       free(*pp);
+               free(G.global_argv);
+       }
+#endif
+       argv[0] = sv->sv_argv0;
+       G.global_argv = sv->sv_g_argv;
+       G.global_argc = sv->sv_g_argc;
+       IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
+}
+
+
+/* Basic theory of signal handling in shell
+ * ========================================
+ * This does not describe what hush does, rather, it is current understanding
+ * what it _should_ do. If it doesn't, it's a bug.
+ * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
+ *
+ * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
+ * is finished or backgrounded. It is the same in interactive and
+ * non-interactive shells, and is the same regardless of whether
+ * a user trap handler is installed or a shell special one is in effect.
+ * ^C or ^Z from keyboard seems to execute "at once" because it usually
+ * backgrounds (i.e. stops) or kills all members of currently running
+ * pipe.
+ *
+ * Wait builtin is interruptible by signals for which user trap is set
+ * or by SIGINT in interactive shell.
+ *
+ * Trap handlers will execute even within trap handlers. (right?)
+ *
+ * User trap handlers are forgotten when subshell ("(cmd)") is entered,
+ * except for handlers set to '' (empty string).
+ *
+ * If job control is off, backgrounded commands ("cmd &")
+ * have SIGINT, SIGQUIT set to SIG_IGN.
+ *
+ * Commands which are run in command substitution ("`cmd`")
+ * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
+ *
+ * Ordinary commands have signals set to SIG_IGN/DFL as inherited
+ * by the shell from its parent.
+ *
+ * Signals which differ from SIG_DFL action
+ * (note: child (i.e., [v]forked) shell is not an interactive shell):
+ *
+ * SIGQUIT: ignore
+ * SIGTERM (interactive): ignore
+ * SIGHUP (interactive):
+ *    send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
+ * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
+ *    Note that ^Z is handled not by trapping SIGTSTP, but by seeing
+ *    that all pipe members are stopped. Try this in bash:
+ *    while :; do :; done - ^Z does not background it
+ *    (while :; do :; done) - ^Z backgrounds it
+ * SIGINT (interactive): wait for last pipe, ignore the rest
+ *    of the command line, show prompt. NB: ^C does not send SIGINT
+ *    to interactive shell while shell is waiting for a pipe,
+ *    since shell is bg'ed (is not in foreground process group).
+ *    Example 1: this waits 5 sec, but does not execute ls:
+ *    "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
+ *    Example 2: this does not wait and does not execute ls:
+ *    "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
+ *    Example 3: this does not wait 5 sec, but executes ls:
+ *    "sleep 5; ls -l" + press ^C
+ *    Example 4: this does not wait and does not execute ls:
+ *    "sleep 5 & wait; ls -l" + press ^C
+ *
+ * (What happens to signals which are IGN on shell start?)
+ * (What happens with signal mask on shell start?)
+ *
+ * Old implementation
+ * ==================
+ * We use in-kernel pending signal mask to determine which signals were sent.
+ * We block all signals which we don't want to take action immediately,
+ * i.e. we block all signals which need to have special handling as described
+ * above, and all signals which have traps set.
+ * After each pipe execution, we extract any pending signals via sigtimedwait()
+ * and act on them.
+ *
+ * unsigned special_sig_mask: a mask of such "special" signals
+ * sigset_t blocked_set:  current blocked signal set
+ *
+ * "trap - SIGxxx":
+ *    clear bit in blocked_set unless it is also in special_sig_mask
+ * "trap 'cmd' SIGxxx":
+ *    set bit in blocked_set (even if 'cmd' is '')
+ * after [v]fork, if we plan to be a shell:
+ *    unblock signals with special interactive handling
+ *    (child shell is not interactive),
+ *    unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
+ * after [v]fork, if we plan to exec:
+ *    POSIX says fork clears pending signal mask in child - no need to clear it.
+ *    Restore blocked signal set to one inherited by shell just prior to exec.
+ *
+ * Note: as a result, we do not use signal handlers much. The only uses
+ * are to count SIGCHLDs
+ * and to restore tty pgrp on signal-induced exit.
+ *
+ * Note 2 (compat):
+ * Standard says "When a subshell is entered, traps that are not being ignored
+ * are set to the default actions". bash interprets it so that traps which
+ * are set to '' (ignore) are NOT reset to defaults. We do the same.
+ *
+ * Problem: the above approach makes it unwieldy to catch signals while
+ * we are in read builtin, or while we read commands from stdin:
+ * masked signals are not visible!
+ *
+ * New implementation
+ * ==================
+ * We record each signal we are interested in by installing signal handler
+ * for them - a bit like emulating kernel pending signal mask in userspace.
+ * We are interested in: signals which need to have special handling
+ * as described above, and all signals which have traps set.
+ * Signals are recorded in pending_set.
+ * After each pipe execution, we extract any pending signals
+ * and act on them.
+ *
+ * unsigned special_sig_mask: a mask of shell-special signals.
+ * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
+ * char *traps[sig] if trap for sig is set (even if it's '').
+ * sigset_t pending_set: set of sigs we received.
+ *
+ * "trap - SIGxxx":
+ *    if sig is in special_sig_mask, set handler back to:
+ *        record_pending_signo, or to IGN if it's a tty stop signal
+ *    if sig is in fatal_sig_mask, set handler back to sigexit.
+ *    else: set handler back to SIG_DFL
+ * "trap 'cmd' SIGxxx":
+ *    set handler to record_pending_signo.
+ * "trap '' SIGxxx":
+ *    set handler to SIG_IGN.
+ * after [v]fork, if we plan to be a shell:
+ *    set signals with special interactive handling to SIG_DFL
+ *    (because child shell is not interactive),
+ *    unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
+ * after [v]fork, if we plan to exec:
+ *    POSIX says fork clears pending signal mask in child - no need to clear it.
+ *
+ * To make wait builtin interruptible, we handle SIGCHLD as special signal,
+ * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
+ *
+ * Note (compat):
+ * Standard says "When a subshell is entered, traps that are not being ignored
+ * are set to the default actions". bash interprets it so that traps which
+ * are set to '' (ignore) are NOT reset to defaults. We do the same.
+ */
+enum {
+       SPECIAL_INTERACTIVE_SIGS = 0
+               | (1 << SIGTERM)
+               | (1 << SIGINT)
+               | (1 << SIGHUP)
+               ,
+       SPECIAL_JOBSTOP_SIGS = 0
+#if ENABLE_HUSH_JOB
+               | (1 << SIGTTIN)
+               | (1 << SIGTTOU)
+               | (1 << SIGTSTP)
+#endif
+               ,
+};
+
+static void record_pending_signo(int sig)
+{
+       sigaddset(&G.pending_set, sig);
+#if ENABLE_HUSH_FAST
+       if (sig == SIGCHLD) {
+               G.count_SIGCHLD++;
+//bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
+       }
+#endif
+}
+
+static sighandler_t install_sighandler(int sig, sighandler_t handler)
+{
+       struct sigaction old_sa;
+
+       /* We could use signal() to install handlers... almost:
+        * except that we need to mask ALL signals while handlers run.
+        * I saw signal nesting in strace, race window isn't small.
+        * SA_RESTART is also needed, but in Linux, signal()
+        * sets SA_RESTART too.
+        */
+       /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
+       /* sigfillset(&G.sa.sa_mask);      - already done */
+       /* G.sa.sa_flags = SA_RESTART;     - already done */
+       G.sa.sa_handler = handler;
+       sigaction(sig, &G.sa, &old_sa);
+       return old_sa.sa_handler;
+}
+
+static void hush_exit(int exitcode) NORETURN;
+
+static void restore_ttypgrp_and__exit(void) NORETURN;
+static void restore_ttypgrp_and__exit(void)
+{
+       /* xfunc has failed! die die die */
+       /* no EXIT traps, this is an escape hatch! */
+       G.exiting = 1;
+       hush_exit(xfunc_error_retval);
+}
+
+#if ENABLE_HUSH_JOB
+
+/* Needed only on some libc:
+ * It was observed that on exit(), fgetc'ed buffered data
+ * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
+ * With the net effect that even after fork(), not vfork(),
+ * exit() in NOEXECed applet in "sh SCRIPT":
+ *     noexec_applet_here
+ *     echo END_OF_SCRIPT
+ * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
+ * This makes "echo END_OF_SCRIPT" executed twice.
+ * Similar problems can be seen with msg_and_die_if_script() -> xfunc_die()
+ * and in `cmd` handling.
+ * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
+ */
+static void fflush_and__exit(void) NORETURN;
+static void fflush_and__exit(void)
+{
+       fflush_all();
+       _exit(xfunc_error_retval);
+}
+
+/* After [v]fork, in child: do not restore tty pgrp on xfunc death */
+# define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
+/* After [v]fork, in parent: restore tty pgrp on xfunc death */
+# define enable_restore_tty_pgrp_on_exit()  (die_func = restore_ttypgrp_and__exit)
+
+/* Restores tty foreground process group, and exits.
+ * May be called as signal handler for fatal signal
+ * (will resend signal to itself, producing correct exit state)
+ * or called directly with -EXITCODE.
+ * We also call it if xfunc is exiting.
+ */
+static void sigexit(int sig) NORETURN;
+static void sigexit(int sig)
+{
+       /* Careful: we can end up here after [v]fork. Do not restore
+        * tty pgrp then, only top-level shell process does that */
+       if (G_saved_tty_pgrp && getpid() == G.root_pid) {
+               /* Disable all signals: job control, SIGPIPE, etc.
+                * Mostly paranoid measure, to prevent infinite SIGTTOU.
+                */
+               sigprocmask_allsigs(SIG_BLOCK);
+               tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
+       }
+
+       /* Not a signal, just exit */
+       if (sig <= 0)
+               _exit(- sig);
+
+       kill_myself_with_sig(sig); /* does not return */
+}
+#else
+
+# define disable_restore_tty_pgrp_on_exit() ((void)0)
+# define enable_restore_tty_pgrp_on_exit()  ((void)0)
+
+#endif
+
+static sighandler_t pick_sighandler(unsigned sig)
+{
+       sighandler_t handler = SIG_DFL;
+       if (sig < sizeof(unsigned)*8) {
+               unsigned sigmask = (1 << sig);
+
+#if ENABLE_HUSH_JOB
+               /* is sig fatal? */
+               if (G_fatal_sig_mask & sigmask)
+                       handler = sigexit;
+               else
+#endif
+               /* sig has special handling? */
+               if (G.special_sig_mask & sigmask) {
+                       handler = record_pending_signo;
+                       /* TTIN/TTOU/TSTP can't be set to record_pending_signo
+                        * in order to ignore them: they will be raised
+                        * in an endless loop when we try to do some
+                        * terminal ioctls! We do have to _ignore_ these.
+                        */
+                       if (SPECIAL_JOBSTOP_SIGS & sigmask)
+                               handler = SIG_IGN;
+               }
+       }
+       return handler;
+}
+
+/* Restores tty foreground process group, and exits. */
+static void hush_exit(int exitcode)
+{
+#if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
+       save_history(G.line_input_state); /* may be NULL */
+#endif
+
+       fflush_all();
+       if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
+               char *argv[3];
+               /* argv[0] is unused */
+               argv[1] = xstrdup(G_traps[0]); /* copy, since EXIT trap handler may modify G_traps[0] */
+               argv[2] = NULL;
+               G.exiting = 1; /* prevent EXIT trap recursion */
+               /* Note: G_traps[0] is not cleared!
+                * "trap" will still show it, if executed
+                * in the handler */
+               builtin_eval(argv);
+       }
+
+#if ENABLE_FEATURE_CLEAN_UP
+       {
+               struct variable *cur_var;
+               if (G.cwd != bb_msg_unknown)
+                       free((char*)G.cwd);
+               cur_var = G.top_var;
+               while (cur_var) {
+                       struct variable *tmp = cur_var;
+                       if (!cur_var->max_len)
+                               free(cur_var->varstr);
+                       cur_var = cur_var->next;
+                       free(tmp);
+               }
+       }
+#endif
+
+       fflush_all();
+#if ENABLE_HUSH_JOB
+       sigexit(- (exitcode & 0xff));
+#else
+       _exit(exitcode);
+#endif
+}
+
+//TODO: return a mask of ALL handled sigs?
+static int check_and_run_traps(void)
+{
+       int last_sig = 0;
+
+       while (1) {
+               int sig;
+
+               if (sigisemptyset(&G.pending_set))
+                       break;
+               sig = 0;
+               do {
+                       sig++;
+                       if (sigismember(&G.pending_set, sig)) {
+                               sigdelset(&G.pending_set, sig);
+                               goto got_sig;
+                       }
+               } while (sig < NSIG);
+               break;
+ got_sig:
+#if ENABLE_HUSH_TRAP
+               if (G_traps && G_traps[sig]) {
+                       debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
+                       if (G_traps[sig][0]) {
+                               /* We have user-defined handler */
+                               smalluint save_rcode;
+                               int save_pre;
+                               char *argv[3];
+                               /* argv[0] is unused */
+                               argv[1] = xstrdup(G_traps[sig]);
+                               /* why strdup? trap can modify itself: trap 'trap "echo oops" INT' INT */
+                               argv[2] = NULL;
+                               save_pre = G.pre_trap_exitcode;
+                               G.pre_trap_exitcode = save_rcode = G.last_exitcode;
+                               builtin_eval(argv);
+                               free(argv[1]);
+                               G.pre_trap_exitcode = save_pre;
+                               G.last_exitcode = save_rcode;
+# if ENABLE_HUSH_FUNCTIONS
+                               if (G.return_exitcode >= 0) {
+                                       debug_printf_exec("trap exitcode:%d\n", G.return_exitcode);
+                                       G.last_exitcode = G.return_exitcode;
+                               }
+# endif
+                               last_sig = sig;
+                       } /* else: "" trap, ignoring signal */
+                       continue;
+               }
+#endif
+               /* not a trap: special action */
+               switch (sig) {
+               case SIGINT:
+                       debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
+                       G.flag_SIGINT = 1;
+                       last_sig = sig;
+                       break;
+#if ENABLE_HUSH_JOB
+               case SIGHUP: {
+//TODO: why are we doing this? ash and dash don't do this,
+//they have no handler for SIGHUP at all,
+//they rely on kernel to send SIGHUP+SIGCONT to orphaned process groups
+                       struct pipe *job;
+                       debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
+                       /* bash is observed to signal whole process groups,
+                        * not individual processes */
+                       for (job = G.job_list; job; job = job->next) {
+                               if (job->pgrp <= 0)
+                                       continue;
+                               debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
+                               if (kill(- job->pgrp, SIGHUP) == 0)
+                                       kill(- job->pgrp, SIGCONT);
+                       }
+                       sigexit(SIGHUP);
+               }
+#endif
+#if ENABLE_HUSH_FAST
+               case SIGCHLD:
+                       debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
+                       G.count_SIGCHLD++;
+//bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
+                       /* Note:
+                        * We don't do 'last_sig = sig' here -> NOT returning this sig.
+                        * This simplifies wait builtin a bit.
+                        */
+                       break;
+#endif
+               default: /* ignored: */
+                       debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
+                       /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
+                       /* Note:
+                        * We don't do 'last_sig = sig' here -> NOT returning this sig.
+                        * Example: wait is not interrupted by TERM
+                        * in interactive shell, because TERM is ignored.
+                        */
+                       break;
+               }
+       }
+       return last_sig;
+}
+
+
+static const char *get_cwd(int force)
+{
+       if (force || G.cwd == NULL) {
+               /* xrealloc_getcwd_or_warn(arg) calls free(arg),
+                * we must not try to free(bb_msg_unknown) */
+               if (G.cwd == bb_msg_unknown)
+                       G.cwd = NULL;
+               G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
+               if (!G.cwd)
+                       G.cwd = bb_msg_unknown;
+       }
+       return G.cwd;
+}
+
+
+/*
+ * Shell and environment variable support
+ */
+static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
+{
+       struct variable **pp;
+       struct variable *cur;
+
+       pp = &G.top_var;
+       while ((cur = *pp) != NULL) {
+               if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
+                       return pp;
+               pp = &cur->next;
+       }
+       return NULL;
+}
+
+static const char* FAST_FUNC get_local_var_value(const char *name)
+{
+       struct variable **vpp;
+       unsigned len = strlen(name);
+
+       if (G.expanded_assignments) {
+               char **cpp = G.expanded_assignments;
+               while (*cpp) {
+                       char *cp = *cpp;
+                       if (strncmp(cp, name, len) == 0 && cp[len] == '=')
+                               return cp + len + 1;
+                       cpp++;
+               }
+       }
+
+       vpp = get_ptr_to_local_var(name, len);
+       if (vpp)
+               return (*vpp)->varstr + len + 1;
+
+       if (strcmp(name, "PPID") == 0)
+               return utoa(G.root_ppid);
+       // bash compat: UID? EUID?
+#if ENABLE_HUSH_RANDOM_SUPPORT
+       if (strcmp(name, "RANDOM") == 0)
+               return utoa(next_random(&G.random_gen));
+#endif
+#if ENABLE_HUSH_LINENO_VAR
+       if (strcmp(name, "LINENO") == 0)
+               return utoa(G.execute_lineno);
+#endif
+#if BASH_EPOCH_VARS
+       {
+               const char *fmt = NULL;
+               if (strcmp(name, "EPOCHSECONDS") == 0)
+                       fmt = "%llu";
+               else if (strcmp(name, "EPOCHREALTIME") == 0)
+                       fmt = "%llu.%06u";
+               if (fmt) {
+                       struct timeval tv;
+                       xgettimeofday(&tv);
+                       sprintf(G.epoch_buf, fmt, (unsigned long long)tv.tv_sec,
+                                       (unsigned)tv.tv_usec);
+                       return G.epoch_buf;
+               }
+       }
+#endif
+       return NULL;
+}
+
+#if ENABLE_HUSH_GETOPTS
+static void handle_changed_special_names(const char *name, unsigned name_len)
+{
+       if (name_len == 6) {
+               if (strncmp(name, "OPTIND", 6) == 0) {
+                       G.getopt_count = 0;
+                       return;
+               }
+       }
+}
+#else
+/* Do not even bother evaluating arguments */
+# define handle_changed_special_names(...) ((void)0)
+#endif
+
+/* str holds "NAME=VAL" and is expected to be malloced.
+ * We take ownership of it.
+ */
+#define SETFLAG_EXPORT   (1 << 0)
+#define SETFLAG_UNEXPORT (1 << 1)
+#define SETFLAG_MAKE_RO  (1 << 2)
+#define SETFLAG_VARLVL_SHIFT   3
+static int set_local_var(char *str, unsigned flags)
+{
+       struct variable **cur_pp;
+       struct variable *cur;
+       char *free_me = NULL;
+       char *eq_sign;
+       int name_len;
+       int retval;
+       unsigned local_lvl = (flags >> SETFLAG_VARLVL_SHIFT);
+
+       eq_sign = strchr(str, '=');
+       if (HUSH_DEBUG && !eq_sign)
+               bb_simple_error_msg_and_die("BUG in setvar");
+
+       name_len = eq_sign - str + 1; /* including '=' */
+       cur_pp = &G.top_var;
+       while ((cur = *cur_pp) != NULL) {
+               if (strncmp(cur->varstr, str, name_len) != 0) {
+                       cur_pp = &cur->next;
+                       continue;
+               }
+
+               /* We found an existing var with this name */
+               if (cur->flg_read_only) {
+                       bb_error_msg("%s: readonly variable", str);
+                       free(str);
+//NOTE: in bash, assignment in "export READONLY_VAR=Z" fails, and sets $?=1,
+//but export per se succeeds (does put the var in env). We don't mimic that.
+                       return -1;
+               }
+               if (flags & SETFLAG_UNEXPORT) { // && cur->flg_export ?
+                       debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
+                       *eq_sign = '\0';
+                       unsetenv(str);
+                       *eq_sign = '=';
+               }
+               if (cur->var_nest_level < local_lvl) {
+                       /* bash 3.2.33(1) and exported vars:
+                        * # export z=z
+                        * # f() { local z=a; env | grep ^z; }
+                        * # f
+                        * z=a
+                        * # env | grep ^z
+                        * z=z
+                        */
+                       if (cur->flg_export)
+                               flags |= SETFLAG_EXPORT;
+                       /* New variable is local ("local VAR=VAL" or
+                        * "VAR=VAL cmd")
+                        * and existing one is global, or local
+                        * on a lower level that new one.
+                        * Remove it from global variable list:
+                        */
+                       *cur_pp = cur->next;
+                       if (G.shadowed_vars_pp) {
+                               /* Save in "shadowed" list */
+                               debug_printf_env("shadowing %s'%s'/%u by '%s'/%u\n",
+                                       cur->flg_export ? "exported " : "",
+                                       cur->varstr, cur->var_nest_level, str, local_lvl
+                               );
+                               cur->next = *G.shadowed_vars_pp;
+                               *G.shadowed_vars_pp = cur;
+                       } else {
+                               /* Came from pseudo_exec_argv(), no need to save: delete it */
+                               debug_printf_env("shadow-deleting %s'%s'/%u by '%s'/%u\n",
+                                       cur->flg_export ? "exported " : "",
+                                       cur->varstr, cur->var_nest_level, str, local_lvl
+                               );
+                               if (cur->max_len == 0) /* allocated "VAR=VAL"? */
+                                       free_me = cur->varstr; /* then free it later */
+                               free(cur);
+                       }
+                       break;
+               }
+
+               if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
+                       debug_printf_env("assignement '%s' does not change anything\n", str);
+ free_and_exp:
+                       free(str);
+                       goto exp;
+               }
+
+               /* Replace the value in the found "struct variable" */
+               if (cur->max_len != 0) {
+                       if (cur->max_len >= strnlen(str, cur->max_len + 1)) {
+                               /* This one is from startup env, reuse space */
+                               debug_printf_env("reusing startup env for '%s'\n", str);
+                               strcpy(cur->varstr, str);
+                               goto free_and_exp;
+                       }
+                       /* Can't reuse */
+                       cur->max_len = 0;
+                       goto set_str_and_exp;
+               }
+               /* max_len == 0 signifies "malloced" var, which we can
+                * (and have to) free. But we can't free(cur->varstr) here:
+                * if cur->flg_export is 1, it is in the environment.
+                * We should either unsetenv+free, or wait until putenv,
+                * then putenv(new)+free(old).
+                */
+               free_me = cur->varstr;
+               goto set_str_and_exp;
+       }
+
+       /* Not found or shadowed - create new variable struct */
+       debug_printf_env("%s: alloc new var '%s'/%u\n", __func__, str, local_lvl);
+       cur = xzalloc(sizeof(*cur));
+       cur->var_nest_level = local_lvl;
+       cur->next = *cur_pp;
+       *cur_pp = cur;
+
+ set_str_and_exp:
+       cur->varstr = str;
+ exp:
+#if !BB_MMU || ENABLE_HUSH_READONLY
+       if (flags & SETFLAG_MAKE_RO) {
+               cur->flg_read_only = 1;
+       }
+#endif
+       if (flags & SETFLAG_EXPORT)
+               cur->flg_export = 1;
+       retval = 0;
+       if (cur->flg_export) {
+               if (flags & SETFLAG_UNEXPORT) {
+                       cur->flg_export = 0;
+                       /* unsetenv was already done */
+               } else {
+                       debug_printf_env("%s: putenv '%s'/%u\n", __func__, cur->varstr, cur->var_nest_level);
+                       retval = putenv(cur->varstr);
+                       /* fall through to "free(free_me)" -
+                        * only now we can free old exported malloced string
+                        */
+               }
+       }
+       free(free_me);
+
+       handle_changed_special_names(cur->varstr, name_len - 1);
+
+       return retval;
+}
+
+static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
+{
+       char *var = xasprintf("%s=%s", name, val);
+       set_local_var(var, /*flag:*/ 0);
+}
+
+/* Used at startup and after each cd */
+static void set_pwd_var(unsigned flag)
+{
+       set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)), flag);
+}
+
+#if ENABLE_HUSH_UNSET || ENABLE_HUSH_GETOPTS
+static int unset_local_var_len(const char *name, int name_len)
+{
+       struct variable *cur;
+       struct variable **cur_pp;
+
+       cur_pp = &G.top_var;
+       while ((cur = *cur_pp) != NULL) {
+               if (strncmp(cur->varstr, name, name_len) == 0
+                && cur->varstr[name_len] == '='
+               ) {
+                       if (cur->flg_read_only) {
+                               bb_error_msg("%s: readonly variable", name);
+                               return EXIT_FAILURE;
+                       }
+
+                       *cur_pp = cur->next;
+                       debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
+                       bb_unsetenv(cur->varstr);
+                       if (!cur->max_len)
+                               free(cur->varstr);
+                       free(cur);
+
+                       break;
+               }
+               cur_pp = &cur->next;
+       }
+
+       /* Handle "unset LINENO" et al even if did not find the variable to unset */
+       handle_changed_special_names(name, name_len);
+
+       return EXIT_SUCCESS;
+}
+
+static int unset_local_var(const char *name)
+{
+       return unset_local_var_len(name, strlen(name));
+}
+#endif
+
+
+/*
+ * Helpers for "var1=val1 var2=val2 cmd" feature
+ */
+static void add_vars(struct variable *var)
+{
+       struct variable *next;
+
+       while (var) {
+               next = var->next;
+               var->next = G.top_var;
+               G.top_var = var;
+               if (var->flg_export) {
+                       debug_printf_env("%s: restoring exported '%s'/%u\n", __func__, var->varstr, var->var_nest_level);
+                       putenv(var->varstr);
+               } else {
+                       debug_printf_env("%s: restoring variable '%s'/%u\n", __func__, var->varstr, var->var_nest_level);
+               }
+               var = next;
+       }
+}
+
+/* We put strings[i] into variable table and possibly putenv them.
+ * If variable is read only, we can free the strings[i]
+ * which attempts to overwrite it.
+ * The strings[] vector itself is freed.
+ */
+static void set_vars_and_save_old(char **strings)
+{
+       char **s;
+
+       if (!strings)
+               return;
+
+       s = strings;
+       while (*s) {
+               struct variable *var_p;
+               struct variable **var_pp;
+               char *eq;
+
+               eq = strchr(*s, '=');
+               if (HUSH_DEBUG && !eq)
+                       bb_simple_error_msg_and_die("BUG in varexp4");
+               var_pp = get_ptr_to_local_var(*s, eq - *s);
+               if (var_pp) {
+                       var_p = *var_pp;
+                       if (var_p->flg_read_only) {
+                               char **p;
+                               bb_error_msg("%s: readonly variable", *s);
+                               /*
+                                * "VAR=V BLTIN" unsets VARs after BLTIN completes.
+                                * If VAR is readonly, leaving it in the list
+                                * after asssignment error (msg above)
+                                * causes doubled error message later, on unset.
+                                */
+                               debug_printf_env("removing/freeing '%s' element\n", *s);
+                               free(*s);
+                               p = s;
+                               do { *p = p[1]; p++; } while (*p);
+                               goto next;
+                       }
+                       /* below, set_local_var() with nest level will
+                        * "shadow" (remove) this variable from
+                        * global linked list.
+                        */
+               }
+               debug_printf_env("%s: env override '%s'/%u\n", __func__, *s, G.var_nest_level);
+               set_local_var(*s, (G.var_nest_level << SETFLAG_VARLVL_SHIFT) | SETFLAG_EXPORT);
+               s++;
+ next: ;
+       }
+       free(strings);
+}
+
+
+/*
+ * Unicode helper
+ */
+static void reinit_unicode_for_hush(void)
+{
+       /* Unicode support should be activated even if LANG is set
+        * _during_ shell execution, not only if it was set when
+        * shell was started. Therefore, re-check LANG every time:
+        */
+       if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
+        || ENABLE_UNICODE_USING_LOCALE
+       ) {
+               const char *s = get_local_var_value("LC_ALL");
+               if (!s) s = get_local_var_value("LC_CTYPE");
+               if (!s) s = get_local_var_value("LANG");
+               reinit_unicode(s);
+       }
+}
+
+/*
+ * in_str support (strings, and "strings" read from files).
+ */
+
+#if ENABLE_HUSH_INTERACTIVE
+/* To test correct lineedit/interactive behavior, type from command line:
+ *     echo $P\
+ *     \
+ *     AT\
+ *     H\
+ *     \
+ * It exercises a lot of corner cases.
+ */
+static const char *setup_prompt_string(void)
+{
+       const char *prompt_str;
+
+       debug_printf_prompt("%s promptmode:%d\n", __func__, G.promptmode);
+
+# if ENABLE_FEATURE_EDITING_FANCY_PROMPT
+       prompt_str = get_local_var_value(G.promptmode == 0 ? "PS1" : "PS2");
+       if (!prompt_str)
+               prompt_str = "";
+# else
+       prompt_str = "> "; /* if PS2, else... */
+       if (G.promptmode == 0) { /* PS1 */
+               /* No fancy prompts supported, (re)generate "CURDIR $ " by hand */
+               free(G.PS1);
+               /* bash uses $PWD value, even if it is set by user.
+                * It uses current dir only if PWD is unset.
+                * We always use current dir. */
+               prompt_str = G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
+       }
+# endif
+       debug_printf("prompt_str '%s'\n", prompt_str);
+       return prompt_str;
+}
+static int get_user_input(struct in_str *i)
+{
+# if ENABLE_FEATURE_EDITING
+       /* In EDITING case, this function reads next input line,
+        * saves it in i->p, then returns 1st char of it.
+        */
+       int r;
+       const char *prompt_str;
+
+       prompt_str = setup_prompt_string();
+       for (;;) {
+               reinit_unicode_for_hush();
+               G.flag_SIGINT = 0;
+               /* buglet: SIGINT will not make new prompt to appear _at once_,
+                * only after <Enter>. (^C works immediately) */
+               r = read_line_input(G.line_input_state, prompt_str,
+                               G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1
+               );
+               /* read_line_input intercepts ^C, "convert" it to SIGINT */
+               if (r == 0) {
+                       raise(SIGINT);
+               }
+               check_and_run_traps();
+               if (r != 0 && !G.flag_SIGINT)
+                       break;
+               /* ^C or SIGINT: repeat */
+               /* bash prints ^C even on real SIGINT (non-kbd generated) */
+               write(STDOUT_FILENO, "^C\n", 3);
+               G.last_exitcode = 128 | SIGINT;
+       }
+       if (r < 0) {
+               /* EOF/error detected */
+               /* ^D on interactive input goes to next line before exiting: */
+               write(STDOUT_FILENO, "\n", 1);
+               i->p = NULL;
+               i->peek_buf[0] = r = EOF;
+               return r;
+       }
+       i->p = G.user_input_buf;
+       return (unsigned char)*i->p++;
+# else
+       /* In !EDITING case, this function gets called for every char.
+        * Buffering happens deeper in the call chain, in hfgetc(i->file).
+        */
+       int r;
+
+       for (;;) {
+               G.flag_SIGINT = 0;
+               if (i->last_char == '\0' || i->last_char == '\n') {
+                       const char *prompt_str = setup_prompt_string();
+                       /* Why check_and_run_traps here? Try this interactively:
+                        * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
+                        * $ <[enter], repeatedly...>
+                        * Without check_and_run_traps, handler never runs.
+                        */
+                       check_and_run_traps();
+                       fputs_stdout(prompt_str);
+                       fflush_all();
+               }
+               r = hfgetc(i->file);
+               /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
+                * no ^C masking happens during fgetc, no special code for ^C:
+                * it generates SIGINT as usual.
+                */
+               check_and_run_traps();
+               if (r != '\0' && !G.flag_SIGINT)
+                       break;
+               if (G.flag_SIGINT) {
+                       /* ^C or SIGINT: repeat */
+                       /* bash prints ^C even on real SIGINT (non-kbd generated) */
+                       /* kernel prints "^C" itself, just print newline: */
+                       write(STDOUT_FILENO, "\n", 1);
+                       G.last_exitcode = 128 | SIGINT;
+               }
+       }
+       return r;
+# endif
+}
+/* This is the magic location that prints prompts
+ * and gets data back from the user */
+static int fgetc_interactive(struct in_str *i)
+{
+       int ch;
+       /* If it's interactive stdin, get new line. */
+       if (G_interactive_fd && i->file == G.HFILE_stdin) {
+               /* Returns first char (or EOF), the rest is in i->p[] */
+               ch = get_user_input(i);
+               G.promptmode = 1; /* PS2 */
+               debug_printf_prompt("%s promptmode=%d\n", __func__, G.promptmode);
+       } else {
+               /* Not stdin: script file, sourced file, etc */
+               do ch = hfgetc(i->file); while (ch == '\0');
+       }
+       return ch;
+}
+#else  /* !INTERACTIVE */
+static ALWAYS_INLINE int fgetc_interactive(struct in_str *i)
+{
+       int ch;
+       do ch = hfgetc(i->file); while (ch == '\0');
+       return ch;
+}
+#endif  /* !INTERACTIVE */
+
+static int i_getch(struct in_str *i)
+{
+       int ch;
+
+       if (!i->file) {
+               /* string-based in_str */
+               ch = (unsigned char)*i->p;
+               if (ch != '\0') {
+                       i->p++;
+                       i->last_char = ch;
+                       return ch;
+               }
+               return EOF;
+       }
+
+       /* FILE-based in_str */
+
+#if ENABLE_FEATURE_EDITING
+       /* This can be stdin, check line editing char[] buffer */
+       if (i->p && *i->p != '\0') {
+               ch = (unsigned char)*i->p++;
+               goto out;
+       }
+#endif
+       /* peek_buf[] is an int array, not char. Can contain EOF. */
+       ch = i->peek_buf[0];
+       if (ch != 0) {
+               int ch2 = i->peek_buf[1];
+               i->peek_buf[0] = ch2;
+               if (ch2 == 0) /* very likely, avoid redundant write */
+                       goto out;
+               i->peek_buf[1] = 0;
+               goto out;
+       }
+
+       ch = fgetc_interactive(i);
+ out:
+       debug_printf("file_get: got '%c' %d\n", ch, ch);
+       i->last_char = ch;
+#if ENABLE_HUSH_LINENO_VAR
+       if (ch == '\n') {
+               G.parse_lineno++;
+               debug_printf_parse("G.parse_lineno++ = %u\n", G.parse_lineno);
+       }
+#endif
+       return ch;
+}
+
+static int i_peek(struct in_str *i)
+{
+       int ch;
+
+       if (!i->file) {
+               /* string-based in_str */
+               /* Doesn't report EOF on NUL. None of the callers care. */
+               return (unsigned char)*i->p;
+       }
+
+       /* FILE-based in_str */
+
+#if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
+       /* This can be stdin, check line editing char[] buffer */
+       if (i->p && *i->p != '\0')
+               return (unsigned char)*i->p;
+#endif
+       /* peek_buf[] is an int array, not char. Can contain EOF. */
+       ch = i->peek_buf[0];
+       if (ch != 0)
+               return ch;
+
+       /* Need to get a new char */
+       ch = fgetc_interactive(i);
+       debug_printf("file_peek: got '%c' %d\n", ch, ch);
+
+       /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
+#if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
+       if (i->p) {
+               i->p -= 1;
+               return ch;
+       }
+#endif
+       i->peek_buf[0] = ch;
+       /*i->peek_buf[1] = 0; - already is */
+       return ch;
+}
+
+/* Only ever called if i_peek() was called, and did not return EOF.
+ * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
+ * not end-of-line. Therefore we never need to read a new editing line here.
+ */
+static int i_peek2(struct in_str *i)
+{
+       int ch;
+
+       /* There are two cases when i->p[] buffer exists.
+        * (1) it's a string in_str.
+        * (2) It's a file, and we have a saved line editing buffer.
+        * In both cases, we know that i->p[0] exists and not NUL, and
+        * the peek2 result is in i->p[1].
+        */
+       if (i->p)
+               return (unsigned char)i->p[1];
+
+       /* Now we know it is a file-based in_str. */
+
+       /* peek_buf[] is an int array, not char. Can contain EOF. */
+       /* Is there 2nd char? */
+       ch = i->peek_buf[1];
+       if (ch == 0) {
+               /* We did not read it yet, get it now */
+               do ch = hfgetc(i->file); while (ch == '\0');
+               i->peek_buf[1] = ch;
+       }
+
+       debug_printf("file_peek2: got '%c' %d\n", ch, ch);
+       return ch;
+}
+
+static int i_getch_and_eat_bkslash_nl(struct in_str *input)
+{
+       for (;;) {
+               int ch, ch2;
+
+               ch = i_getch(input);
+               if (ch != '\\')
+                       return ch;
+               ch2 = i_peek(input);
+               if (ch2 != '\n')
+                       return ch;
+               /* backslash+newline, skip it */
+               i_getch(input);
+       }
+}
+
+/* Note: this function _eats_ \<newline> pairs, safe to use plain
+ * i_getch() after it instead of i_getch_and_eat_bkslash_nl().
+ */
+static int i_peek_and_eat_bkslash_nl(struct in_str *input)
+{
+       for (;;) {
+               int ch, ch2;
+
+               ch = i_peek(input);
+               if (ch != '\\')
+                       return ch;
+               ch2 = i_peek2(input);
+               if (ch2 != '\n')
+                       return ch;
+               /* backslash+newline, skip it */
+               i_getch(input);
+               i_getch(input);
+       }
+}
+
+static void setup_file_in_str(struct in_str *i, HFILE *fp)
+{
+       memset(i, 0, sizeof(*i));
+       i->file = fp;
+       /* i->p = NULL; */
+}
+
+static void setup_string_in_str(struct in_str *i, const char *s)
+{
+       memset(i, 0, sizeof(*i));
+       /*i->file = NULL */;
+       i->p = s;
+}
+
+
+/*
+ * o_string support
+ */
+#define B_CHUNK  (32 * sizeof(char*))
+
+static void o_reset_to_empty_unquoted(o_string *o)
+{
+       o->length = 0;
+       o->has_quoted_part = 0;
+       if (o->data)
+               o->data[0] = '\0';
+}
+
+static void o_free_and_set_NULL(o_string *o)
+{
+       free(o->data);
+       memset(o, 0, sizeof(*o));
+}
+
+static ALWAYS_INLINE void o_free(o_string *o)
+{
+       free(o->data);
+}
+
+static void o_grow_by(o_string *o, int len)
+{
+       if (o->length + len > o->maxlen) {
+               o->maxlen += (2 * len) | (B_CHUNK-1);
+               o->data = xrealloc(o->data, 1 + o->maxlen);
+       }
+}
+
+static void o_addchr(o_string *o, int ch)
+{
+       debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
+       if (o->length < o->maxlen) {
+               /* likely. avoid o_grow_by() call */
+ add:
+               o->data[o->length] = ch;
+               o->length++;
+               o->data[o->length] = '\0';
+               return;
+       }
+       o_grow_by(o, 1);
+       goto add;
+}
+
+#if 0
+/* Valid only if we know o_string is not empty */
+static void o_delchr(o_string *o)
+{
+       o->length--;
+       o->data[o->length] = '\0';
+}
+#endif
+
+static void o_addblock(o_string *o, const char *str, int len)
+{
+       o_grow_by(o, len);
+       ((char*)mempcpy(&o->data[o->length], str, len))[0] = '\0';
+       o->length += len;
+}
+
+static void o_addstr(o_string *o, const char *str)
+{
+       o_addblock(o, str, strlen(str));
+}
+
+static void o_addstr_with_NUL(o_string *o, const char *str)
+{
+       o_addblock(o, str, strlen(str) + 1);
+}
+
+#if !BB_MMU
+static void nommu_addchr(o_string *o, int ch)
+{
+       if (o)
+               o_addchr(o, ch);
+}
+#else
+# define nommu_addchr(o, str) ((void)0)
+#endif
+
+#if ENABLE_HUSH_MODE_X
+static void x_mode_addchr(int ch)
+{
+       o_addchr(&G.x_mode_buf, ch);
+}
+static void x_mode_addstr(const char *str)
+{
+       o_addstr(&G.x_mode_buf, str);
+}
+static void x_mode_addblock(const char *str, int len)
+{
+       o_addblock(&G.x_mode_buf, str, len);
+}
+static void x_mode_prefix(void)
+{
+       int n = G.x_mode_depth;
+       do x_mode_addchr('+'); while (--n >= 0);
+}
+static void x_mode_flush(void)
+{
+       int len = G.x_mode_buf.length;
+       if (len <= 0)
+               return;
+       if (G.x_mode_fd > 0) {
+               G.x_mode_buf.data[len] = '\n';
+               full_write(G.x_mode_fd, G.x_mode_buf.data, len + 1);
+       }
+       G.x_mode_buf.length = 0;
+}
+#endif
+
+/*
+ * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
+ * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
+ * Apparently, on unquoted $v bash still does globbing
+ * ("v='*.txt'; echo $v" prints all .txt files),
+ * but NOT brace expansion! Thus, there should be TWO independent
+ * quoting mechanisms on $v expansion side: one protects
+ * $v from brace expansion, and other additionally protects "$v" against globbing.
+ * We have only second one.
+ */
+
+#if ENABLE_HUSH_BRACE_EXPANSION
+# define MAYBE_BRACES "{}"
+#else
+# define MAYBE_BRACES ""
+#endif
+
+/* My analysis of quoting semantics tells me that state information
+ * is associated with a destination, not a source.
+ */
+static void o_addqchr(o_string *o, int ch)
+{
+       int sz = 1;
+       /* '-' is included because of this case:
+        * >filename0 >filename1 >filename9; v='-'; echo filename[0"$v"9]
+        */
+       char *found = strchr("*?[-\\" MAYBE_BRACES, ch);
+       if (found)
+               sz++;
+       o_grow_by(o, sz);
+       if (found) {
+               o->data[o->length] = '\\';
+               o->length++;
+       }
+       o->data[o->length] = ch;
+       o->length++;
+       o->data[o->length] = '\0';
+}
+
+static void o_addQchr(o_string *o, int ch)
+{
+       int sz = 1;
+       if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
+        && strchr("*?[-\\" MAYBE_BRACES, ch)
+       ) {
+               sz++;
+               o->data[o->length] = '\\';
+               o->length++;
+       }
+       o_grow_by(o, sz);
+       o->data[o->length] = ch;
+       o->length++;
+       o->data[o->length] = '\0';
+}
+
+static void o_addqblock(o_string *o, const char *str, int len)
+{
+       while (len) {
+               char ch;
+               int sz;
+               int ordinary_cnt = strcspn(str, "*?[-\\" MAYBE_BRACES);
+               if (ordinary_cnt > len) /* paranoia */
+                       ordinary_cnt = len;
+               o_addblock(o, str, ordinary_cnt);
+               if (ordinary_cnt == len)
+                       return; /* NUL is already added by o_addblock */
+               str += ordinary_cnt;
+               len -= ordinary_cnt + 1; /* we are processing + 1 char below */
+
+               ch = *str++;
+               sz = 1;
+               if (ch) { /* it is necessarily one of "*?[-\\" MAYBE_BRACES */
+                       sz++;
+                       o->data[o->length] = '\\';
+                       o->length++;
+               }
+               o_grow_by(o, sz);
+               o->data[o->length] = ch;
+               o->length++;
+       }
+       o->data[o->length] = '\0';
+}
+
+static void o_addQblock(o_string *o, const char *str, int len)
+{
+       if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
+               o_addblock(o, str, len);
+               return;
+       }
+       o_addqblock(o, str, len);
+}
+
+static void o_addQstr(o_string *o, const char *str)
+{
+       o_addQblock(o, str, strlen(str));
+}
+
+/* A special kind of o_string for $VAR and `cmd` expansion.
+ * It contains char* list[] at the beginning, which is grown in 16 element
+ * increments. Actual string data starts at the next multiple of 16 * (char*).
+ * list[i] contains an INDEX (int!) into this string data.
+ * It means that if list[] needs to grow, data needs to be moved higher up
+ * but list[i]'s need not be modified.
+ * NB: remembering how many list[i]'s you have there is crucial.
+ * o_finalize_list() operation post-processes this structure - calculates
+ * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
+ */
+#if DEBUG_EXPAND || DEBUG_GLOB
+static void debug_print_list(const char *prefix, o_string *o, int n)
+{
+       char **list = (char**)o->data;
+       int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
+       int i = 0;
+
+       indent();
+       fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
+                       prefix, list, n, string_start, o->length, o->maxlen,
+                       !!(o->o_expflags & EXP_FLAG_GLOB),
+                       o->has_quoted_part,
+                       !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
+       while (i < n) {
+               indent();
+               fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
+                               o->data + (int)(uintptr_t)list[i] + string_start,
+                               o->data + (int)(uintptr_t)list[i] + string_start);
+               i++;
+       }
+       if (n) {
+               const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
+               indent();
+               fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
+       }
+}
+#else
+# define debug_print_list(prefix, o, n) ((void)0)
+#endif
+
+/* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
+ * in list[n] so that it points past last stored byte so far.
+ * It returns n+1. */
+static int o_save_ptr_helper(o_string *o, int n)
+{
+       char **list = (char**)o->data;
+       int string_start;
+       int string_len;
+
+       if (!o->has_empty_slot) {
+               string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
+               string_len = o->length - string_start;
+               if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
+                       debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
+                       /* list[n] points to string_start, make space for 16 more pointers */
+                       o->maxlen += 0x10 * sizeof(list[0]);
+                       o->data = xrealloc(o->data, o->maxlen + 1);
+                       list = (char**)o->data;
+                       memmove(list + n + 0x10, list + n, string_len);
+                       /*
+                        * expand_on_ifs() has a "previous argv[] ends in IFS?"
+                        * check. (grep for -prev-ifs-check-).
+                        * Ensure that argv[-1][last] is not garbage
+                        * but zero bytes, to save index check there.
+                        */
+                       list[n + 0x10 - 1] = 0;
+                       o->length += 0x10 * sizeof(list[0]);
+               } else {
+                       debug_printf_list("list[%d]=%d string_start=%d\n",
+                                       n, string_len, string_start);
+               }
+       } else {
+               /* We have empty slot at list[n], reuse without growth */
+               string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
+               string_len = o->length - string_start;
+               debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
+                               n, string_len, string_start);
+               o->has_empty_slot = 0;
+       }
+       o->has_quoted_part = 0;
+       list[n] = (char*)(uintptr_t)string_len;
+       return n + 1;
+}
+
+/* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
+static int o_get_last_ptr(o_string *o, int n)
+{
+       char **list = (char**)o->data;
+       int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
+
+       return ((int)(uintptr_t)list[n-1]) + string_start;
+}
+
+/*
+ * Globbing routines.
+ *
+ * Most words in commands need to be globbed, even ones which are
+ * (single or double) quoted. This stems from the possiblity of
+ * constructs like "abc"* and 'abc'* - these should be globbed.
+ * Having a different code path for fully-quoted strings ("abc",
+ * 'abc') would only help performance-wise, but we still need
+ * code for partially-quoted strings.
+ *
+ * Unfortunately, if we want to match bash and ash behavior in all cases,
+ * the logic can't be "shell-syntax argument is first transformed
+ * to a string, then globbed, and if globbing does not match anything,
+ * it is used verbatim". Here are two examples where it fails:
+ *
+ *     echo 'b\*'?
+ *
+ * The globbing can't be avoided (because of '?' at the end).
+ * The glob pattern is: b\\\*? - IOW, both \ and * are literals
+ * and are glob-escaped. If this does not match, bash/ash print b\*?
+ * - IOW: they "unbackslash" the glob pattern.
+ * Now, look at this:
+ *
+ *     v='\\\*'; echo b$v?
+ *
+ * The glob pattern is the same here: b\\\*? - the unquoted $v expansion
+ * should be used as glob pattern with no changes. However, if glob
+ * does not match, bash/ash print b\\\*? - NOT THE SAME as first example!
+ *
+ * ash implements this by having an encoded representation of the word
+ * to glob, which IS NOT THE SAME as the glob pattern - it has more data.
+ * Glob pattern is derived from it. If glob fails, the decision what result
+ * should be is made using that encoded representation. Not glob pattern.
+ */
+
+#if ENABLE_HUSH_BRACE_EXPANSION
+/* There in a GNU extension, GLOB_BRACE, but it is not usable:
+ * first, it processes even {a} (no commas), second,
+ * I didn't manage to make it return strings when they don't match
+ * existing files. Need to re-implement it.
+ */
+
+/* Helper */
+static int glob_needed(const char *s)
+{
+       while (*s) {
+               if (*s == '\\') {
+                       if (!s[1])
+                               return 0;
+                       s += 2;
+                       continue;
+               }
+               if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
+                       return 1;
+               s++;
+       }
+       return 0;
+}
+/* Return pointer to next closing brace or to comma */
+static const char *next_brace_sub(const char *cp)
+{
+       unsigned depth = 0;
+       cp++;
+       while (*cp != '\0') {
+               if (*cp == '\\') {
+                       if (*++cp == '\0')
+                               break;
+                       cp++;
+                       continue;
+               }
+               if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
+                       break;
+               if (*cp++ == '{')
+                       depth++;
+       }
+
+       return *cp != '\0' ? cp : NULL;
+}
+/* Recursive brace globber. Note: may garble pattern[]. */
+static int glob_brace(char *pattern, o_string *o, int n)
+{
+       char *new_pattern_buf;
+       const char *begin;
+       const char *next;
+       const char *rest;
+       const char *p;
+       size_t rest_len;
+
+       debug_printf_glob("glob_brace('%s')\n", pattern);
+
+       begin = pattern;
+       while (1) {
+               if (*begin == '\0')
+                       goto simple_glob;
+               if (*begin == '{') {
+                       /* Find the first sub-pattern and at the same time
+                        * find the rest after the closing brace */
+                       next = next_brace_sub(begin);
+                       if (next == NULL) {
+                               /* An illegal expression */
+                               goto simple_glob;
+                       }
+                       if (*next == '}') {
+                               /* "{abc}" with no commas - illegal
+                                * brace expr, disregard and skip it */
+                               begin = next + 1;
+                               continue;
+                       }
+                       break;
+               }
+               if (*begin == '\\' && begin[1] != '\0')
+                       begin++;
+               begin++;
+       }
+       debug_printf_glob("begin:%s\n", begin);
+       debug_printf_glob("next:%s\n", next);
+
+       /* Now find the end of the whole brace expression */
+       rest = next;
+       while (*rest != '}') {
+               rest = next_brace_sub(rest);
+               if (rest == NULL) {
+                       /* An illegal expression */
+                       goto simple_glob;
+               }
+               debug_printf_glob("rest:%s\n", rest);
+       }
+       rest_len = strlen(++rest) + 1;
+
+       /* We are sure the brace expression is well-formed */
+
+       /* Allocate working buffer large enough for our work */
+       new_pattern_buf = xmalloc(strlen(pattern));
+
+       /* We have a brace expression.  BEGIN points to the opening {,
+        * NEXT points past the terminator of the first element, and REST
+        * points past the final }.  We will accumulate result names from
+        * recursive runs for each brace alternative in the buffer using
+        * GLOB_APPEND.  */
+
+       p = begin + 1;
+       while (1) {
+               /* Construct the new glob expression */
+               memcpy(
+                       mempcpy(
+                               mempcpy(new_pattern_buf,
+                                       /* We know the prefix for all sub-patterns */
+                                       pattern, begin - pattern),
+                               p, next - p),
+                       rest, rest_len);
+
+               /* Note: glob_brace() may garble new_pattern_buf[].
+                * That's why we re-copy prefix every time (1st memcpy above).
+                */
+               n = glob_brace(new_pattern_buf, o, n);
+               if (*next == '}') {
+                       /* We saw the last entry */
+                       break;
+               }
+               p = next + 1;
+               next = next_brace_sub(next);
+       }
+       free(new_pattern_buf);
+       return n;
+
+ simple_glob:
+       {
+               int gr;
+               glob_t globdata;
+
+               memset(&globdata, 0, sizeof(globdata));
+               gr = glob(pattern, 0, NULL, &globdata);
+               debug_printf_glob("glob('%s'):%d\n", pattern, gr);
+               if (gr != 0) {
+                       if (gr == GLOB_NOMATCH) {
+                               globfree(&globdata);
+                               /* NB: garbles parameter */
+                               unbackslash(pattern);
+                               o_addstr_with_NUL(o, pattern);
+                               debug_printf_glob("glob pattern '%s' is literal\n", pattern);
+                               return o_save_ptr_helper(o, n);
+                       }
+                       if (gr == GLOB_NOSPACE)
+                               bb_die_memory_exhausted();
+                       /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
+                        * but we didn't specify it. Paranoia again. */
+                       bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
+               }
+               if (globdata.gl_pathv && globdata.gl_pathv[0]) {
+                       char **argv = globdata.gl_pathv;
+                       while (1) {
+                               o_addstr_with_NUL(o, *argv);
+                               n = o_save_ptr_helper(o, n);
+                               argv++;
+                               if (!*argv)
+                                       break;
+                       }
+               }
+               globfree(&globdata);
+       }
+       return n;
+}
+/* Performs globbing on last list[],
+ * saving each result as a new list[].
+ */
+static int perform_glob(o_string *o, int n)
+{
+       char *pattern, *copy;
+
+       debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
+       if (!o->data)
+               return o_save_ptr_helper(o, n);
+       pattern = o->data + o_get_last_ptr(o, n);
+       debug_printf_glob("glob pattern '%s'\n", pattern);
+       if (!glob_needed(pattern)) {
+               /* unbackslash last string in o in place, fix length */
+               o->length = unbackslash(pattern) - o->data;
+               debug_printf_glob("glob pattern '%s' is literal\n", pattern);
+               return o_save_ptr_helper(o, n);
+       }
+
+       copy = xstrdup(pattern);
+       /* "forget" pattern in o */
+       o->length = pattern - o->data;
+       n = glob_brace(copy, o, n);
+       free(copy);
+       if (DEBUG_GLOB)
+               debug_print_list("perform_glob returning", o, n);
+       return n;
+}
+
+#else /* !HUSH_BRACE_EXPANSION */
+
+/* Helper */
+static int glob_needed(const char *s)
+{
+       while (*s) {
+               if (*s == '\\') {
+                       if (!s[1])
+                               return 0;
+                       s += 2;
+                       continue;
+               }
+               if (*s == '*' || *s == '[' || *s == '?')
+                       return 1;
+               s++;
+       }
+       return 0;
+}
+/* Performs globbing on last list[],
+ * saving each result as a new list[].
+ */
+static int perform_glob(o_string *o, int n)
+{
+       glob_t globdata;
+       int gr;
+       char *pattern;
+
+       debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
+       if (!o->data)
+               return o_save_ptr_helper(o, n);
+       pattern = o->data + o_get_last_ptr(o, n);
+       debug_printf_glob("glob pattern '%s'\n", pattern);
+       if (!glob_needed(pattern)) {
+ literal:
+               /* unbackslash last string in o in place, fix length */
+               o->length = unbackslash(pattern) - o->data;
+               debug_printf_glob("glob pattern '%s' is literal\n", pattern);
+               return o_save_ptr_helper(o, n);
+       }
+
+       memset(&globdata, 0, sizeof(globdata));
+       /* Can't use GLOB_NOCHECK: it does not unescape the string.
+        * If we glob "*.\*" and don't find anything, we need
+        * to fall back to using literal "*.*", but GLOB_NOCHECK
+        * will return "*.\*"!
+        */
+       gr = glob(pattern, 0, NULL, &globdata);
+       debug_printf_glob("glob('%s'):%d\n", pattern, gr);
+       if (gr != 0) {
+               if (gr == GLOB_NOMATCH) {
+                       globfree(&globdata);
+                       goto literal;
+               }
+               if (gr == GLOB_NOSPACE)
+                       bb_die_memory_exhausted();
+               /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
+                * but we didn't specify it. Paranoia again. */
+               bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
+       }
+       if (globdata.gl_pathv && globdata.gl_pathv[0]) {
+               char **argv = globdata.gl_pathv;
+               /* "forget" pattern in o */
+               o->length = pattern - o->data;
+               while (1) {
+                       o_addstr_with_NUL(o, *argv);
+                       n = o_save_ptr_helper(o, n);
+                       argv++;
+                       if (!*argv)
+                               break;
+               }
+       }
+       globfree(&globdata);
+       if (DEBUG_GLOB)
+               debug_print_list("perform_glob returning", o, n);
+       return n;
+}
+
+#endif /* !HUSH_BRACE_EXPANSION */
+
+/* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
+ * Otherwise, just finish current list[] and start new */
+static int o_save_ptr(o_string *o, int n)
+{
+       if (o->o_expflags & EXP_FLAG_GLOB) {
+               /* If o->has_empty_slot, list[n] was already globbed
+                * (if it was requested back then when it was filled)
+                * so don't do that again! */
+               if (!o->has_empty_slot)
+                       return perform_glob(o, n); /* o_save_ptr_helper is inside */
+       }
+       return o_save_ptr_helper(o, n);
+}
+
+/* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
+static char **o_finalize_list(o_string *o, int n)
+{
+       char **list;
+       int string_start;
+
+       if (DEBUG_EXPAND)
+               debug_print_list("finalized", o, n);
+       debug_printf_expand("finalized n:%d\n", n);
+       list = (char**)o->data;
+       string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
+       list[--n] = NULL;
+       while (n) {
+               n--;
+               list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
+       }
+       return list;
+}
+
+static void free_pipe_list(struct pipe *pi);
+
+/* Returns pi->next - next pipe in the list */
+static struct pipe *free_pipe(struct pipe *pi)
+{
+       struct pipe *next;
+       int i;
+
+       debug_printf_clean("free_pipe (pid %d)\n", getpid());
+       for (i = 0; i < pi->num_cmds; i++) {
+               struct command *command;
+               struct redir_struct *r, *rnext;
+
+               command = &pi->cmds[i];
+               debug_printf_clean("  command %d:\n", i);
+               if (command->argv) {
+                       if (DEBUG_CLEAN) {
+                               int a;
+                               char **p;
+                               for (a = 0, p = command->argv; *p; a++, p++) {
+                                       debug_printf_clean("   argv[%d] = %s\n", a, *p);
+                               }
+                       }
+                       free_strings(command->argv);
+                       //command->argv = NULL;
+               }
+               /* not "else if": on syntax error, we may have both! */
+               if (command->group) {
+                       debug_printf_clean("   begin group (cmd_type:%d)\n",
+                                       command->cmd_type);
+                       free_pipe_list(command->group);
+                       debug_printf_clean("   end group\n");
+                       //command->group = NULL;
+               }
+               /* else is crucial here.
+                * If group != NULL, child_func is meaningless */
+#if ENABLE_HUSH_FUNCTIONS
+               else if (command->child_func) {
+                       debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
+                       command->child_func->parent_cmd = NULL;
+               }
+#endif
+#if !BB_MMU
+               free(command->group_as_string);
+               //command->group_as_string = NULL;
+#endif
+               for (r = command->redirects; r; r = rnext) {
+                       debug_printf_clean("   redirect %d%s",
+                                       r->rd_fd, redir_table[r->rd_type].descrip);
+                       /* guard against the case >$FOO, where foo is unset or blank */
+                       if (r->rd_filename) {
+                               debug_printf_clean(" fname:'%s'\n", r->rd_filename);
+                               free(r->rd_filename);
+                               //r->rd_filename = NULL;
+                       }
+                       debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
+                       rnext = r->next;
+                       free(r);
+               }
+               //command->redirects = NULL;
+       }
+       free(pi->cmds);   /* children are an array, they get freed all at once */
+       //pi->cmds = NULL;
+#if ENABLE_HUSH_JOB
+       free(pi->cmdtext);
+       //pi->cmdtext = NULL;
+#endif
+
+       next = pi->next;
+       free(pi);
+       return next;
+}
+
+static void free_pipe_list(struct pipe *pi)
+{
+       while (pi) {
+#if HAS_KEYWORDS
+               debug_printf_clean("pipe reserved word %d\n", pi->res_word);
+#endif
+               debug_printf_clean("pipe followup code %d\n", pi->followup);
+               pi = free_pipe(pi);
+       }
+}
+
+
+/*** Parsing routines ***/
+
+#ifndef debug_print_tree
+static void debug_print_tree(struct pipe *pi, int lvl)
+{
+       static const char *const PIPE[] = {
+               [PIPE_SEQ] = "SEQ",
+               [PIPE_AND] = "AND",
+               [PIPE_OR ] = "OR" ,
+               [PIPE_BG ] = "BG" ,
+       };
+       static const char *RES[] = {
+               [RES_NONE ] = "NONE" ,
+# if ENABLE_HUSH_IF
+               [RES_IF   ] = "IF"   ,
+               [RES_THEN ] = "THEN" ,
+               [RES_ELIF ] = "ELIF" ,
+               [RES_ELSE ] = "ELSE" ,
+               [RES_FI   ] = "FI"   ,
+# endif
+# if ENABLE_HUSH_LOOPS
+               [RES_FOR  ] = "FOR"  ,
+               [RES_WHILE] = "WHILE",
+               [RES_UNTIL] = "UNTIL",
+               [RES_DO   ] = "DO"   ,
+               [RES_DONE ] = "DONE" ,
+# endif
+# if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
+               [RES_IN   ] = "IN"   ,
+# endif
+# if ENABLE_HUSH_CASE
+               [RES_CASE ] = "CASE" ,
+               [RES_CASE_IN ] = "CASE_IN" ,
+               [RES_MATCH] = "MATCH",
+               [RES_CASE_BODY] = "CASE_BODY",
+               [RES_ESAC ] = "ESAC" ,
+# endif
+               [RES_XXXX ] = "XXXX" ,
+               [RES_SNTX ] = "SNTX" ,
+       };
+       static const char *const CMDTYPE[] = {
+               "{}",
+               "()",
+               "[noglob]",
+# if ENABLE_HUSH_FUNCTIONS
+               "func()",
+# endif
+       };
+
+       int pin, prn;
+
+       pin = 0;
+       while (pi) {
+               fdprintf(2, "%*spipe %d #cmds:%d %sres_word=%s followup=%d %s\n",
+                               lvl*2, "",
+                               pin,
+                               pi->num_cmds,
+                               (IF_HAS_KEYWORDS(pi->pi_inverted ? "! " :) ""),
+                               RES[pi->res_word],
+                               pi->followup, PIPE[pi->followup]
+               );
+               prn = 0;
+               while (prn < pi->num_cmds) {
+                       struct command *command = &pi->cmds[prn];
+                       char **argv = command->argv;
+
+                       fdprintf(2, "%*s cmd %d assignment_cnt:%d",
+                                       lvl*2, "", prn,
+                                       command->assignment_cnt);
+# if ENABLE_HUSH_LINENO_VAR
+                       fdprintf(2, " LINENO:%u", command->lineno);
+# endif
+                       if (command->group) {
+                               fdprintf(2, " group %s: (argv=%p)%s%s\n",
+                                               CMDTYPE[command->cmd_type],
+                                               argv
+# if !BB_MMU
+                                               , " group_as_string:", command->group_as_string
+# else
+                                               , "", ""
+# endif
+                               );
+                               debug_print_tree(command->group, lvl+1);
+                               prn++;
+                               continue;
+                       }
+                       if (argv) while (*argv) {
+                               fdprintf(2, " '%s'", *argv);
+                               argv++;
+                       }
+                       if (command->redirects)
+                               fdprintf(2, " {redir}");
+                       fdprintf(2, "\n");
+                       prn++;
+               }
+               pi = pi->next;
+               pin++;
+       }
+}
+#endif /* debug_print_tree */
+
+static struct pipe *new_pipe(void)
+{
+       struct pipe *pi;
+       pi = xzalloc(sizeof(struct pipe));
+       /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
+       return pi;
+}
+
+/* Command (member of a pipe) is complete, or we start a new pipe
+ * if ctx->command is NULL.
+ * No errors possible here.
+ */
+static int done_command(struct parse_context *ctx)
+{
+       /* The command is really already in the pipe structure, so
+        * advance the pipe counter and make a new, null command. */
+       struct pipe *pi = ctx->pipe;
+       struct command *command = ctx->command;
+
+#if 0  /* Instead we emit error message at run time */
+       if (ctx->pending_redirect) {
+               /* For example, "cmd >" (no filename to redirect to) */
+               syntax_error("invalid redirect");
+               ctx->pending_redirect = NULL;
+       }
+#endif
+
+       if (command) {
+               if (IS_NULL_CMD(command)) {
+                       debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
+                       goto clear_and_ret;
+               }
+               pi->num_cmds++;
+               debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
+               //debug_print_tree(ctx->list_head, 20);
+       } else {
+               debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
+       }
+
+       /* Only real trickiness here is that the uncommitted
+        * command structure is not counted in pi->num_cmds. */
+       pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
+       ctx->command = command = &pi->cmds[pi->num_cmds];
+ clear_and_ret:
+       memset(command, 0, sizeof(*command));
+#if ENABLE_HUSH_LINENO_VAR
+       command->lineno = G.parse_lineno;
+       debug_printf_parse("command->lineno = G.parse_lineno (%u)\n", G.parse_lineno);
+#endif
+       return pi->num_cmds; /* used only for 0/nonzero check */
+}
+
+static void done_pipe(struct parse_context *ctx, pipe_style type)
+{
+       int not_null;
+
+       debug_printf_parse("done_pipe entered, followup %d\n", type);
+       /* Close previous command */
+       not_null = done_command(ctx);
+#if HAS_KEYWORDS
+       ctx->pipe->pi_inverted = ctx->ctx_inverted;
+       ctx->ctx_inverted = 0;
+       ctx->pipe->res_word = ctx->ctx_res_w;
+#endif
+       if (type == PIPE_BG && ctx->list_head != ctx->pipe) {
+               /* Necessary since && and || have precedence over &:
+                * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
+                * in a backgrounded subshell.
+                */
+               struct pipe *pi;
+               struct command *command;
+
+               /* Is this actually this construct, all pipes end with && or ||? */
+               pi = ctx->list_head;
+               while (pi != ctx->pipe) {
+                       if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
+                               goto no_conv;
+                       pi = pi->next;
+               }
+
+               debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
+               pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
+               pi = xzalloc(sizeof(*pi));
+               pi->followup = PIPE_BG;
+               pi->num_cmds = 1;
+               pi->cmds = xzalloc(sizeof(pi->cmds[0]));
+               command = &pi->cmds[0];
+               if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
+                       command->cmd_type = CMD_NORMAL;
+               command->group = ctx->list_head;
+#if !BB_MMU
+               command->group_as_string = xstrndup(
+                           ctx->as_string.data,
+                           ctx->as_string.length - 1 /* do not copy last char, "&" */
+               );
+#endif
+               /* Replace all pipes in ctx with one newly created */
+               ctx->list_head = ctx->pipe = pi;
+               /* for cases like "cmd && &", do not be tricked by last command
+                * being null - the entire {...} & is NOT null! */
+               not_null = 1;
+       } else {
+ no_conv:
+               ctx->pipe->followup = type;
+       }
+
+       /* Without this check, even just <enter> on command line generates
+        * tree of three NOPs (!). Which is harmless but annoying.
+        * IOW: it is safe to do it unconditionally. */
+       if (not_null
+#if ENABLE_HUSH_IF
+        || ctx->ctx_res_w == RES_FI
+#endif
+#if ENABLE_HUSH_LOOPS
+        || ctx->ctx_res_w == RES_DONE
+        || ctx->ctx_res_w == RES_FOR
+        || ctx->ctx_res_w == RES_IN
+#endif
+#if ENABLE_HUSH_CASE
+        || ctx->ctx_res_w == RES_ESAC
+#endif
+       ) {
+               struct pipe *new_p;
+               debug_printf_parse("done_pipe: adding new pipe: "
+                               "not_null:%d ctx->ctx_res_w:%d\n",
+                               not_null, ctx->ctx_res_w);
+               new_p = new_pipe();
+               ctx->pipe->next = new_p;
+               ctx->pipe = new_p;
+               /* RES_THEN, RES_DO etc are "sticky" -
+                * they remain set for pipes inside if/while.
+                * This is used to control execution.
+                * RES_FOR and RES_IN are NOT sticky (needed to support
+                * cases where variable or value happens to match a keyword):
+                */
+#if ENABLE_HUSH_LOOPS
+               if (ctx->ctx_res_w == RES_FOR
+                || ctx->ctx_res_w == RES_IN)
+                       ctx->ctx_res_w = RES_NONE;
+#endif
+#if ENABLE_HUSH_CASE
+               if (ctx->ctx_res_w == RES_MATCH)
+                       ctx->ctx_res_w = RES_CASE_BODY;
+               if (ctx->ctx_res_w == RES_CASE)
+                       ctx->ctx_res_w = RES_CASE_IN;
+#endif
+               ctx->command = NULL; /* trick done_command below */
+               /* Create the memory for command, roughly:
+                * ctx->pipe->cmds = new struct command;
+                * ctx->command = &ctx->pipe->cmds[0];
+                */
+               done_command(ctx);
+               //debug_print_tree(ctx->list_head, 10);
+       }
+       debug_printf_parse("done_pipe return\n");
+}
+
+static void initialize_context(struct parse_context *ctx)
+{
+       memset(ctx, 0, sizeof(*ctx));
+       if (MAYBE_ASSIGNMENT != 0)
+               ctx->is_assignment = MAYBE_ASSIGNMENT;
+       ctx->pipe = ctx->list_head = new_pipe();
+       /* Create the memory for command, roughly:
+        * ctx->pipe->cmds = new struct command;
+        * ctx->command = &ctx->pipe->cmds[0];
+        */
+       done_command(ctx);
+}
+
+/* If a reserved word is found and processed, parse context is modified
+ * and 1 is returned.
+ */
+#if HAS_KEYWORDS
+struct reserved_combo {
+       char literal[6];
+       unsigned char res;
+       unsigned char assignment_flag;
+       uint32_t flag;
+};
+enum {
+       FLAG_END   = (1 << RES_NONE ),
+# if ENABLE_HUSH_IF
+       FLAG_IF    = (1 << RES_IF   ),
+       FLAG_THEN  = (1 << RES_THEN ),
+       FLAG_ELIF  = (1 << RES_ELIF ),
+       FLAG_ELSE  = (1 << RES_ELSE ),
+       FLAG_FI    = (1 << RES_FI   ),
+# endif
+# if ENABLE_HUSH_LOOPS
+       FLAG_FOR   = (1 << RES_FOR  ),
+       FLAG_WHILE = (1 << RES_WHILE),
+       FLAG_UNTIL = (1 << RES_UNTIL),
+       FLAG_DO    = (1 << RES_DO   ),
+       FLAG_DONE  = (1 << RES_DONE ),
+       FLAG_IN    = (1 << RES_IN   ),
+# endif
+# if ENABLE_HUSH_CASE
+       FLAG_MATCH = (1 << RES_MATCH),
+       FLAG_ESAC  = (1 << RES_ESAC ),
+# endif
+       FLAG_START = (1 << RES_XXXX ),
+};
+
+static const struct reserved_combo* match_reserved_word(o_string *word)
+{
+       /* Mostly a list of accepted follow-up reserved words.
+        * FLAG_END means we are done with the sequence, and are ready
+        * to turn the compound list into a command.
+        * FLAG_START means the word must start a new compound list.
+        */
+       static const struct reserved_combo reserved_list[] ALIGN4 = {
+# if ENABLE_HUSH_IF
+               { "!",     RES_NONE,  NOT_ASSIGNMENT  , 0 },
+               { "if",    RES_IF,    MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
+               { "then",  RES_THEN,  MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
+               { "elif",  RES_ELIF,  MAYBE_ASSIGNMENT, FLAG_THEN },
+               { "else",  RES_ELSE,  MAYBE_ASSIGNMENT, FLAG_FI   },
+               { "fi",    RES_FI,    NOT_ASSIGNMENT  , FLAG_END  },
+# endif
+# if ENABLE_HUSH_LOOPS
+               { "for",   RES_FOR,   NOT_ASSIGNMENT  , FLAG_IN | FLAG_DO | FLAG_START },
+               { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
+               { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
+               { "in",    RES_IN,    NOT_ASSIGNMENT  , FLAG_DO   },
+               { "do",    RES_DO,    MAYBE_ASSIGNMENT, FLAG_DONE },
+               { "done",  RES_DONE,  NOT_ASSIGNMENT  , FLAG_END  },
+# endif
+# if ENABLE_HUSH_CASE
+               { "case",  RES_CASE,  NOT_ASSIGNMENT  , FLAG_MATCH | FLAG_START },
+               { "esac",  RES_ESAC,  NOT_ASSIGNMENT  , FLAG_END  },
+# endif
+       };
+       const struct reserved_combo *r;
+
+       for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
+               if (strcmp(word->data, r->literal) == 0)
+                       return r;
+       }
+       return NULL;
+}
+/* Return NULL: not a keyword, else: keyword
+ */
+static const struct reserved_combo* reserved_word(struct parse_context *ctx)
+{
+# if ENABLE_HUSH_CASE
+       static const struct reserved_combo reserved_match = {
+               "",        RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
+       };
+# endif
+       const struct reserved_combo *r;
+
+       if (ctx->word.has_quoted_part)
+               return 0;
+       r = match_reserved_word(&ctx->word);
+       if (!r)
+               return r; /* NULL */
+
+       debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
+# if ENABLE_HUSH_CASE
+       if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
+               /* "case word IN ..." - IN part starts first MATCH part */
+               r = &reserved_match;
+       } else
+# endif
+       if (r->flag == 0) { /* '!' */
+               if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
+                       syntax_error("! ! command");
+                       ctx->ctx_res_w = RES_SNTX;
+               }
+               ctx->ctx_inverted = 1;
+               return r;
+       }
+       if (r->flag & FLAG_START) {
+               struct parse_context *old;
+
+               old = xmemdup(ctx, sizeof(*ctx));
+               debug_printf_parse("push stack %p\n", old);
+               initialize_context(ctx);
+               ctx->stack = old;
+       } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
+               syntax_error_at(ctx->word.data);
+               ctx->ctx_res_w = RES_SNTX;
+               return r;
+       } else {
+               /* "{...} fi" is ok. "{...} if" is not
+                * Example:
+                * if { echo foo; } then { echo bar; } fi */
+               if (ctx->command->group)
+                       done_pipe(ctx, PIPE_SEQ);
+       }
+
+       ctx->ctx_res_w = r->res;
+       ctx->old_flag = r->flag;
+       ctx->is_assignment = r->assignment_flag;
+       debug_printf_parse("ctx->is_assignment='%s'\n", assignment_flag[ctx->is_assignment]);
+
+       if (ctx->old_flag & FLAG_END) {
+               struct parse_context *old;
+
+               done_pipe(ctx, PIPE_SEQ);
+               debug_printf_parse("pop stack %p\n", ctx->stack);
+               old = ctx->stack;
+               old->command->group = ctx->list_head;
+               old->command->cmd_type = CMD_NORMAL;
+# if !BB_MMU
+               /* At this point, the compound command's string is in
+                * ctx->as_string... except for the leading keyword!
+                * Consider this example: "echo a | if true; then echo a; fi"
+                * ctx->as_string will contain "true; then echo a; fi",
+                * with "if " remaining in old->as_string!
+                */
+               {
+                       char *str;
+                       int len = old->as_string.length;
+                       /* Concatenate halves */
+                       o_addstr(&old->as_string, ctx->as_string.data);
+                       o_free(&ctx->as_string);
+                       /* Find where leading keyword starts in first half */
+                       str = old->as_string.data + len;
+                       if (str > old->as_string.data)
+                               str--; /* skip whitespace after keyword */
+                       while (str > old->as_string.data && isalpha(str[-1]))
+                               str--;
+                       /* Ugh, we're done with this horrid hack */
+                       old->command->group_as_string = xstrdup(str);
+                       debug_printf_parse("pop, remembering as:'%s'\n",
+                                       old->command->group_as_string);
+               }
+# endif
+               *ctx = *old;   /* physical copy */
+               free(old);
+       }
+       return r;
+}
+#endif /* HAS_KEYWORDS */
+
+/* Word is complete, look at it and update parsing context.
+ * Normal return is 0. Syntax errors return 1.
+ * Note: on return, word is reset, but not o_free'd!
+ */
+static int done_word(struct parse_context *ctx)
+{
+       struct command *command = ctx->command;
+
+       debug_printf_parse("done_word entered: '%s' %p\n", ctx->word.data, command);
+       if (ctx->word.length == 0 && !ctx->word.has_quoted_part) {
+               debug_printf_parse("done_word return 0: true null, ignored\n");
+               return 0;
+       }
+
+       if (ctx->pending_redirect) {
+               /* We do not glob in e.g. >*.tmp case. bash seems to glob here
+                * only if run as "bash", not "sh" */
+               /* http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html
+                * "2.7 Redirection
+                * If the redirection operator is "<<" or "<<-", the word
+                * that follows the redirection operator shall be
+                * subjected to quote removal; it is unspecified whether
+                * any of the other expansions occur. For the other
+                * redirection operators, the word that follows the
+                * redirection operator shall be subjected to tilde
+                * expansion, parameter expansion, command substitution,
+                * arithmetic expansion, and quote removal.
+                * Pathname expansion shall not be performed
+                * on the word by a non-interactive shell; an interactive
+                * shell may perform it, but shall do so only when
+                * the expansion would result in one word."
+                */
+//bash does not do parameter/command substitution or arithmetic expansion
+//for _heredoc_ redirection word: these constructs look for exact eof marker
+// as written:
+// <<EOF$t
+// <<EOF$((1))
+// <<EOF`true`  [this case also makes heredoc "quoted", a-la <<"EOF". Probably bash-4.3.43 bug]
+
+               ctx->pending_redirect->rd_filename = xstrdup(ctx->word.data);
+               /* Cater for >\file case:
+                * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
+                * Same with heredocs:
+                * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
+                */
+               if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
+                       unbackslash(ctx->pending_redirect->rd_filename);
+                       /* Is it <<"HEREDOC"? */
+                       if (ctx->word.has_quoted_part) {
+                               ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
+                       }
+               }
+               debug_printf_parse("word stored in rd_filename: '%s'\n", ctx->word.data);
+               ctx->pending_redirect = NULL;
+       } else {
+#if HAS_KEYWORDS
+# if ENABLE_HUSH_CASE
+               if (ctx->ctx_dsemicolon
+                && strcmp(ctx->word.data, "esac") != 0 /* not "... pattern) cmd;; esac" */
+               ) {
+                       /* already done when ctx_dsemicolon was set to 1: */
+                       /* ctx->ctx_res_w = RES_MATCH; */
+                       ctx->ctx_dsemicolon = 0;
+               } else
+# endif
+# if defined(CMD_TEST2_SINGLEWORD_NOGLOB)
+               if (command->cmd_type == CMD_TEST2_SINGLEWORD_NOGLOB
+                && strcmp(ctx->word.data, "]]") == 0
+               ) {
+                       /* allow "[[ ]] >file" etc */
+                       command->cmd_type = CMD_SINGLEWORD_NOGLOB;
+               } else
+# endif
+               if (!command->argv /* if it's the first word... */
+# if ENABLE_HUSH_LOOPS
+                && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
+                && ctx->ctx_res_w != RES_IN
+# endif
+# if ENABLE_HUSH_CASE
+                && ctx->ctx_res_w != RES_CASE
+# endif
+               ) {
+                       const struct reserved_combo *reserved;
+                       reserved = reserved_word(ctx);
+                       debug_printf_parse("checking for reserved-ness: %d\n", !!reserved);
+                       if (reserved) {
+# if ENABLE_HUSH_LINENO_VAR
+/* Case:
+ * "while ...; do
+ *     cmd ..."
+ * If we don't close the pipe _now_, immediately after "do", lineno logic
+ * sees "cmd" as starting at "do" - i.e., at the previous line.
+ */
+                               if (0
+                                IF_HUSH_IF(|| reserved->res == RES_THEN)
+                                IF_HUSH_IF(|| reserved->res == RES_ELIF)
+                                IF_HUSH_IF(|| reserved->res == RES_ELSE)
+                                IF_HUSH_LOOPS(|| reserved->res == RES_DO)
+                               ) {
+                                       done_pipe(ctx, PIPE_SEQ);
+                               }
+# endif
+                               o_reset_to_empty_unquoted(&ctx->word);
+                               debug_printf_parse("done_word return %d\n",
+                                               (ctx->ctx_res_w == RES_SNTX));
+                               return (ctx->ctx_res_w == RES_SNTX);
+                       }
+# if defined(CMD_TEST2_SINGLEWORD_NOGLOB)
+                       if (strcmp(ctx->word.data, "[[") == 0) {
+                               command->cmd_type = CMD_TEST2_SINGLEWORD_NOGLOB;
+                       } else
+# endif
+# if defined(CMD_SINGLEWORD_NOGLOB)
+                       if (0
+                       /* In bash, local/export/readonly are special, args
+                        * are assignments and therefore expansion of them
+                        * should be "one-word" expansion:
+                        *  $ export i=`echo 'a  b'` # one arg: "i=a  b"
+                        * compare with:
+                        *  $ ls i=`echo 'a  b'`     # two args: "i=a" and "b"
+                        *  ls: cannot access i=a: No such file or directory
+                        *  ls: cannot access b: No such file or directory
+                        * Note: bash 3.2.33(1) does this only if export word
+                        * itself is not quoted:
+                        *  $ export i=`echo 'aaa  bbb'`; echo "$i"
+                        *  aaa  bbb
+                        *  $ "export" i=`echo 'aaa  bbb'`; echo "$i"
+                        *  aaa
+                        */
+                        IF_HUSH_LOCAL(   || strcmp(ctx->word.data, "local") == 0)
+                        IF_HUSH_EXPORT(  || strcmp(ctx->word.data, "export") == 0)
+                        IF_HUSH_READONLY(|| strcmp(ctx->word.data, "readonly") == 0)
+                       ) {
+                               command->cmd_type = CMD_SINGLEWORD_NOGLOB;
+                       }
+# else
+                       { /* empty block to pair "if ... else" */ }
+# endif
+               }
+#endif /* HAS_KEYWORDS */
+
+               if (command->group) {
+                       /* "{ echo foo; } echo bar" - bad */
+                       syntax_error_at(ctx->word.data);
+                       debug_printf_parse("done_word return 1: syntax error, "
+                                       "groups and arglists don't mix\n");
+                       return 1;
+               }
+
+               /* If this word wasn't an assignment, next ones definitely
+                * can't be assignments. Even if they look like ones. */
+               if (ctx->is_assignment != DEFINITELY_ASSIGNMENT
+                && ctx->is_assignment != WORD_IS_KEYWORD
+               ) {
+                       ctx->is_assignment = NOT_ASSIGNMENT;
+               } else {
+                       if (ctx->is_assignment == DEFINITELY_ASSIGNMENT) {
+                               command->assignment_cnt++;
+                               debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
+                       }
+                       debug_printf_parse("ctx->is_assignment was:'%s'\n", assignment_flag[ctx->is_assignment]);
+                       ctx->is_assignment = MAYBE_ASSIGNMENT;
+               }
+               debug_printf_parse("ctx->is_assignment='%s'\n", assignment_flag[ctx->is_assignment]);
+               command->argv = add_string_to_strings(command->argv, xstrdup(ctx->word.data));
+               debug_print_strings("word appended to argv", command->argv);
+       }
+
+#if ENABLE_HUSH_LOOPS
+       if (ctx->ctx_res_w == RES_FOR) {
+               if (ctx->word.has_quoted_part
+                || endofname(command->argv[0])[0] != '\0'
+               ) {
+                       /* bash says just "not a valid identifier" */
+                       syntax_error("bad variable name in for");
+                       return 1;
+               }
+               /* Force FOR to have just one word (variable name) */
+               /* NB: basically, this makes hush see "for v in ..."
+                * syntax as if it is "for v; in ...". FOR and IN become
+                * two pipe structs in parse tree. */
+               done_pipe(ctx, PIPE_SEQ);
+       }
+#endif
+#if ENABLE_HUSH_CASE
+       /* Force CASE to have just one word */
+       if (ctx->ctx_res_w == RES_CASE) {
+               done_pipe(ctx, PIPE_SEQ);
+       }
+#endif
+
+       o_reset_to_empty_unquoted(&ctx->word);
+
+       debug_printf_parse("done_word return 0\n");
+       return 0;
+}
+
+
+/* Peek ahead in the input to find out if we have a "&n" construct,
+ * as in "2>&1", that represents duplicating a file descriptor.
+ * Return:
+ * REDIRFD_CLOSE if >&- "close fd" construct is seen,
+ * REDIRFD_SYNTAX_ERR if syntax error,
+ * REDIRFD_TO_FILE if no & was seen,
+ * or the number found.
+ */
+#if BB_MMU
+#define parse_redir_right_fd(as_string, input) \
+       parse_redir_right_fd(input)
+#endif
+static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
+{
+       int ch, d, ok;
+
+       ch = i_peek(input);
+       if (ch != '&')
+               return REDIRFD_TO_FILE;
+
+       ch = i_getch(input);  /* get the & */
+       nommu_addchr(as_string, ch);
+       ch = i_peek(input);
+       if (ch == '-') {
+               ch = i_getch(input);
+               nommu_addchr(as_string, ch);
+               return REDIRFD_CLOSE;
+       }
+       d = 0;
+       ok = 0;
+       while (ch != EOF && isdigit(ch)) {
+               d = d*10 + (ch-'0');
+               ok = 1;
+               ch = i_getch(input);
+               nommu_addchr(as_string, ch);
+               ch = i_peek(input);
+       }
+       if (ok) return d;
+
+//TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
+
+       bb_simple_error_msg("ambiguous redirect");
+       return REDIRFD_SYNTAX_ERR;
+}
+
+/* Return code is 0 normal, 1 if a syntax error is detected
+ */
+static int parse_redirect(struct parse_context *ctx,
+               int fd,
+               redir_type style,
+               struct in_str *input)
+{
+       struct command *command = ctx->command;
+       struct redir_struct *redir;
+       struct redir_struct **redirp;
+       int dup_num;
+
+       dup_num = REDIRFD_TO_FILE;
+       if (style != REDIRECT_HEREDOC) {
+               /* Check for a '>&1' type redirect */
+               dup_num = parse_redir_right_fd(&ctx->as_string, input);
+               if (dup_num == REDIRFD_SYNTAX_ERR)
+                       return 1;
+       } else {
+               int ch = i_peek_and_eat_bkslash_nl(input);
+               dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
+               if (dup_num) { /* <<-... */
+                       ch = i_getch(input);
+                       nommu_addchr(&ctx->as_string, ch);
+                       ch = i_peek(input);
+               }
+       }
+
+       if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
+               int ch = i_peek_and_eat_bkslash_nl(input);
+               if (ch == '|') {
+                       /* >|FILE redirect ("clobbering" >).
+                        * Since we do not support "set -o noclobber" yet,
+                        * >| and > are the same for now. Just eat |.
+                        */
+                       ch = i_getch(input);
+                       nommu_addchr(&ctx->as_string, ch);
+               }
+       }
+
+       /* Create a new redir_struct and append it to the linked list */
+       redirp = &command->redirects;
+       while ((redir = *redirp) != NULL) {
+               redirp = &(redir->next);
+       }
+       *redirp = redir = xzalloc(sizeof(*redir));
+       /* redir->next = NULL; */
+       /* redir->rd_filename = NULL; */
+       redir->rd_type = style;
+       redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
+
+       debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
+                               redir_table[style].descrip);
+
+       redir->rd_dup = dup_num;
+       if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
+               /* Erik had a check here that the file descriptor in question
+                * is legit; I postpone that to "run time"
+                * A "-" representation of "close me" shows up as a -3 here */
+               debug_printf_parse("duplicating redirect '%d>&%d'\n",
+                               redir->rd_fd, redir->rd_dup);
+       } else {
+#if 0          /* Instead we emit error message at run time */
+               if (ctx->pending_redirect) {
+                       /* For example, "cmd > <file" */
+                       syntax_error("invalid redirect");
+               }
+#endif
+               /* Set ctx->pending_redirect, so we know what to do at the
+                * end of the next parsed word. */
+               ctx->pending_redirect = redir;
+       }
+       return 0;
+}
+
+/* If a redirect is immediately preceded by a number, that number is
+ * supposed to tell which file descriptor to redirect.  This routine
+ * looks for such preceding numbers.  In an ideal world this routine
+ * needs to handle all the following classes of redirects...
+ *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
+ *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
+ *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
+ *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
+ *
+ * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
+ * "2.7 Redirection
+ * ... If n is quoted, the number shall not be recognized as part of
+ * the redirection expression. For example:
+ * echo \2>a
+ * writes the character 2 into file a"
+ * We are getting it right by setting ->has_quoted_part on any \<char>
+ *
+ * A -1 return means no valid number was found,
+ * the caller should use the appropriate default for this redirection.
+ */
+static int redirect_opt_num(o_string *o)
+{
+       int num;
+
+       if (o->data == NULL)
+               return -1;
+       num = bb_strtou(o->data, NULL, 10);
+       if (errno || num < 0)
+               return -1;
+       o_reset_to_empty_unquoted(o);
+       return num;
+}
+
+#if BB_MMU
+#define fetch_till_str(as_string, input, word, skip_tabs) \
+       fetch_till_str(input, word, skip_tabs)
+#endif
+static char *fetch_till_str(o_string *as_string,
+               struct in_str *input,
+               const char *word,
+               int heredoc_flags)
+{
+       o_string heredoc = NULL_O_STRING;
+       unsigned past_EOL;
+       int prev = 0; /* not \ */
+       int ch;
+
+       /* Starting with "" is necessary for this case:
+        * cat <<EOF
+        *
+        * xxx
+        * EOF
+        */
+       heredoc.data = xzalloc(1); /* start as "", not as NULL */
+
+       goto jump_in;
+
+       while (1) {
+               ch = i_getch(input);
+               if (ch != EOF)
+                       nommu_addchr(as_string, ch);
+               if (ch == '\n' || ch == EOF) {
+ check_heredoc_end:
+                       if ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\') {
+                               /* End-of-line, and not a line continuation */
+                               if (strcmp(heredoc.data + past_EOL, word) == 0) {
+                                       heredoc.data[past_EOL] = '\0';
+                                       debug_printf_heredoc("parsed '%s' heredoc '%s'\n", word, heredoc.data);
+                                       return heredoc.data;
+                               }
+                               if (ch == '\n') {
+                                       /* This is a new line.
+                                        * Remember position and backslash-escaping status.
+                                        */
+                                       o_addchr(&heredoc, ch);
+                                       prev = ch;
+ jump_in:
+                                       past_EOL = heredoc.length;
+                                       /* Get 1st char of next line, possibly skipping leading tabs */
+                                       do {
+                                               ch = i_getch(input);
+                                               if (ch != EOF)
+                                                       nommu_addchr(as_string, ch);
+                                       } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
+                                       /* If this immediately ended the line,
+                                        * go back to end-of-line checks.
+                                        */
+                                       if (ch == '\n')
+                                               goto check_heredoc_end;
+                               }
+                       } else {
+                               /* Backslash-line continuation in an unquoted
+                                * heredoc. This does not need special handling
+                                * for heredoc body (unquoted heredocs are
+                                * expanded on "execution" and that would take
+                                * care of this case too), but not the case
+                                * of line continuation *in terminator*:
+                                *  cat <<EOF
+                                *  Ok1
+                                *  EO\
+                                *  F
+                                */
+                               heredoc.data[--heredoc.length] = '\0';
+                               prev = 0; /* not '\' */
+                               continue;
+                       }
+               }
+               if (ch == EOF) {
+                       o_free(&heredoc);
+                       return NULL; /* error */
+               }
+               o_addchr(&heredoc, ch);
+               nommu_addchr(as_string, ch);
+               if (prev == '\\' && ch == '\\')
+                       /* Correctly handle foo\\<eol> (not a line cont.) */
+                       prev = 0; /* not '\' */
+               else
+                       prev = ch;
+       }
+}
+
+/* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
+ * and load them all. There should be exactly heredoc_cnt of them.
+ */
+#if BB_MMU
+#define fetch_heredocs(as_string, pi, heredoc_cnt, input) \
+       fetch_heredocs(pi, heredoc_cnt, input)
+#endif
+static int fetch_heredocs(o_string *as_string, struct pipe *pi, int heredoc_cnt, struct in_str *input)
+{
+       while (pi && heredoc_cnt) {
+               int i;
+               struct command *cmd = pi->cmds;
+
+               debug_printf_heredoc("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
+                               pi->num_cmds,
+                               cmd->argv ? cmd->argv[0] : "NONE"
+               );
+               for (i = 0; i < pi->num_cmds; i++) {
+                       struct redir_struct *redir = cmd->redirects;
+
+                       debug_printf_heredoc("fetch_heredocs: %d cmd argv0:'%s'\n",
+                                       i, cmd->argv ? cmd->argv[0] : "NONE");
+                       while (redir) {
+                               if (redir->rd_type == REDIRECT_HEREDOC) {
+                                       char *p;
+
+                                       redir->rd_type = REDIRECT_HEREDOC2;
+                                       /* redir->rd_dup is (ab)used to indicate <<- */
+                                       p = fetch_till_str(as_string, input,
+                                                       redir->rd_filename, redir->rd_dup);
+                                       if (!p) {
+                                               syntax_error("unexpected EOF in here document");
+                                               return -1;
+                                       }
+                                       free(redir->rd_filename);
+                                       redir->rd_filename = p;
+                                       heredoc_cnt--;
+                               }
+                               redir = redir->next;
+                       }
+                       if (cmd->group) {
+                               //bb_error_msg("%s:%u heredoc_cnt:%d", __func__, __LINE__, heredoc_cnt);
+                               heredoc_cnt = fetch_heredocs(as_string, cmd->group, heredoc_cnt, input);
+                               //bb_error_msg("%s:%u heredoc_cnt:%d", __func__, __LINE__, heredoc_cnt);
+                               if (heredoc_cnt < 0)
+                                       return heredoc_cnt; /* error */
+                       }
+                       cmd++;
+               }
+               pi = pi->next;
+       }
+       return heredoc_cnt;
+}
+
+
+static int run_list(struct pipe *pi);
+#if BB_MMU
+#define parse_stream(pstring, heredoc_cnt_ptr, input, end_trigger) \
+       parse_stream(heredoc_cnt_ptr, input, end_trigger)
+#endif
+static struct pipe *parse_stream(char **pstring,
+               int *heredoc_cnt_ptr,
+               struct in_str *input,
+               int end_trigger);
+
+/* Returns number of heredocs not yet consumed,
+ * or -1 on error.
+ */
+static int parse_group(struct parse_context *ctx,
+               struct in_str *input, int ch)
+{
+       /* ctx->word contains characters seen prior to ( or {.
+        * Typically it's empty, but for function defs,
+        * it contains function name (without '()'). */
+#if BB_MMU
+# define as_string NULL
+#else
+       char *as_string = NULL;
+#endif
+       struct pipe *pipe_list;
+       int heredoc_cnt = 0;
+       int endch;
+       struct command *command = ctx->command;
+
+       debug_printf_parse("parse_group entered\n");
+#if ENABLE_HUSH_FUNCTIONS
+       if (ch == '(' && !ctx->word.has_quoted_part) {
+               if (ctx->word.length)
+                       if (done_word(ctx))
+                               return -1;
+               if (!command->argv)
+                       goto skip; /* (... */
+               if (command->argv[1]) { /* word word ... (... */
+                       syntax_error_unexpected_ch('(');
+                       return -1;
+               }
+               /* it is "word(..." or "word (..." */
+               do
+                       ch = i_getch(input);
+               while (ch == ' ' || ch == '\t');
+               if (ch != ')') {
+                       syntax_error_unexpected_ch(ch);
+                       return -1;
+               }
+               nommu_addchr(&ctx->as_string, ch);
+               do
+                       ch = i_getch(input);
+               while (ch == ' ' || ch == '\t' || ch == '\n');
+               if (ch != '{' && ch != '(') {
+                       syntax_error_unexpected_ch(ch);
+                       return -1;
+               }
+               nommu_addchr(&ctx->as_string, ch);
+               command->cmd_type = CMD_FUNCDEF;
+               goto skip;
+       }
+#endif
+
+#if 0 /* Prevented by caller */
+       if (command->argv /* word [word]{... */
+        || ctx->word.length /* word{... */
+        || ctx->word.has_quoted_part /* ""{... */
+       ) {
+               syntax_error(NULL);
+               debug_printf_parse("parse_group return -1: "
+                       "syntax error, groups and arglists don't mix\n");
+               return -1;
+       }
+#endif
+
+ IF_HUSH_FUNCTIONS(skip:)
+
+       endch = '}';
+       if (ch == '(') {
+               endch = ')';
+               IF_HUSH_FUNCTIONS(if (command->cmd_type != CMD_FUNCDEF))
+                       command->cmd_type = CMD_SUBSHELL;
+       } else {
+               /* bash does not allow "{echo...", requires whitespace */
+               ch = i_peek(input);
+               if (ch != ' ' && ch != '\t' && ch != '\n'
+                && ch != '('   /* but "{(..." is allowed (without whitespace) */
+               ) {
+                       syntax_error_unexpected_ch(ch);
+                       return -1;
+               }
+               if (ch != '(') {
+                       ch = i_getch(input);
+                       nommu_addchr(&ctx->as_string, ch);
+               }
+       }
+
+       debug_printf_heredoc("calling parse_stream, heredoc_cnt:%d\n", heredoc_cnt);
+       pipe_list = parse_stream(&as_string, &heredoc_cnt, input, endch);
+       debug_printf_heredoc("parse_stream returned: heredoc_cnt:%d\n", heredoc_cnt);
+#if !BB_MMU
+       if (as_string)
+               o_addstr(&ctx->as_string, as_string);
+#endif
+
+       /* empty ()/{} or parse error? */
+       if (!pipe_list || pipe_list == ERR_PTR) {
+               /* parse_stream already emitted error msg */
+               if (!BB_MMU)
+                       free(as_string);
+               debug_printf_parse("parse_group return -1: "
+                       "parse_stream returned %p\n", pipe_list);
+               return -1;
+       }
+#if !BB_MMU
+       as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
+       command->group_as_string = as_string;
+       debug_printf_parse("end of group, remembering as:'%s'\n",
+                       command->group_as_string);
+#endif
+
+#if ENABLE_HUSH_FUNCTIONS
+       /* Convert "f() (cmds)" to "f() {(cmds)}" */
+       if (command->cmd_type == CMD_FUNCDEF && endch == ')') {
+               struct command *cmd2;
+
+               cmd2 = xzalloc(sizeof(*cmd2));
+               cmd2->cmd_type = CMD_SUBSHELL;
+               cmd2->group = pipe_list;
+# if !BB_MMU
+//UNTESTED!
+               cmd2->group_as_string = command->group_as_string;
+               command->group_as_string = xasprintf("(%s)", command->group_as_string);
+# endif
+
+               pipe_list = new_pipe();
+               pipe_list->cmds = cmd2;
+               pipe_list->num_cmds = 1;
+       }
+#endif
+
+       command->group = pipe_list;
+
+       debug_printf_parse("parse_group return %d\n", heredoc_cnt);
+       return heredoc_cnt;
+       /* command remains "open", available for possible redirects */
+#undef as_string
+}
+
+#if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
+/* Subroutines for copying $(...) and `...` things */
+/* '...' */
+static int add_till_single_quote(o_string *dest, struct in_str *input)
+{
+       while (1) {
+               int ch = i_getch(input);
+               if (ch == EOF) {
+                       syntax_error_unterm_ch('\'');
+                       return 0;
+               }
+               if (ch == '\'')
+                       return 1;
+               o_addchr(dest, ch);
+       }
+}
+static int add_till_single_quote_dquoted(o_string *dest, struct in_str *input)
+{
+       while (1) {
+               int ch = i_getch(input);
+               if (ch == EOF) {
+                       syntax_error_unterm_ch('\'');
+                       return 0;
+               }
+               if (ch == '\'')
+                       return 1;
+               o_addqchr(dest, ch);
+       }
+}
+/* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
+static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
+static int add_till_double_quote(o_string *dest, struct in_str *input)
+{
+       while (1) {
+               int ch = i_getch(input);
+               if (ch == EOF) {
+                       syntax_error_unterm_ch('"');
+                       return 0;
+               }
+               if (ch == '"')
+                       return 1;
+               if (ch == '\\') {  /* \x. Copy both chars. */
+                       o_addchr(dest, ch);
+                       ch = i_getch(input);
+               }
+               o_addchr(dest, ch);
+               if (ch == '`') {
+                       if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
+                               return 0;
+                       o_addchr(dest, ch);
+                       continue;
+               }
+               //if (ch == '$') ...
+       }
+}
+/* Process `cmd` - copy contents until "`" is seen. Complicated by
+ * \` quoting.
+ * "Within the backquoted style of command substitution, backslash
+ * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
+ * The search for the matching backquote shall be satisfied by the first
+ * backquote found without a preceding backslash; during this search,
+ * if a non-escaped backquote is encountered within a shell comment,
+ * a here-document, an embedded command substitution of the $(command)
+ * form, or a quoted string, undefined results occur. A single-quoted
+ * or double-quoted string that begins, but does not end, within the
+ * "`...`" sequence produces undefined results."
+ * Example                               Output
+ * echo `echo '\'TEST\`echo ZZ\`BEST`    \TESTZZBEST
+ */
+static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
+{
+       while (1) {
+               int ch = i_getch(input);
+               if (ch == '`')
+                       return 1;
+               if (ch == '\\') {
+                       /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
+                       ch = i_getch(input);
+                       if (ch != '`'
+                        && ch != '$'
+                        && ch != '\\'
+                        && (!in_dquote || ch != '"')
+                       ) {
+                               o_addchr(dest, '\\');
+                       }
+               }
+               if (ch == EOF) {
+                       syntax_error_unterm_ch('`');
+                       return 0;
+               }
+               o_addchr(dest, ch);
+       }
+}
+/* Process $(cmd) - copy contents until ")" is seen. Complicated by
+ * quoting and nested ()s.
+ * "With the $(command) style of command substitution, all characters
+ * following the open parenthesis to the matching closing parenthesis
+ * constitute the command. Any valid shell script can be used for command,
+ * except a script consisting solely of redirections which produces
+ * unspecified results."
+ * Example                              Output
+ * echo $(echo '(TEST)' BEST)           (TEST) BEST
+ * echo $(echo 'TEST)' BEST)            TEST) BEST
+ * echo $(echo \(\(TEST\) BEST)         ((TEST) BEST
+ *
+ * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
+ * can contain arbitrary constructs, just like $(cmd).
+ * In bash compat mode, it needs to also be able to stop on ':' or '/'
+ * for ${var:N[:M]} and ${var/P[/R]} parsing.
+ */
+#define DOUBLE_CLOSE_CHAR_FLAG 0x80
+static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
+{
+       int ch;
+       char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
+# if BASH_SUBSTR || BASH_PATTERN_SUBST
+       char end_char2 = end_ch >> 8;
+# endif
+       end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
+
+# if ENABLE_HUSH_INTERACTIVE
+       G.promptmode = 1; /* PS2 */
+# endif
+       debug_printf_prompt("%s promptmode=%d\n", __func__, G.promptmode);
+
+       while (1) {
+               ch = i_getch(input);
+               if (ch == EOF) {
+                       syntax_error_unterm_ch(end_ch);
+                       return 0;
+               }
+               if (ch == end_ch
+# if BASH_SUBSTR || BASH_PATTERN_SUBST
+                || ch == end_char2
+# endif
+               ) {
+                       if (!dbl)
+                               break;
+                       /* we look for closing )) of $((EXPR)) */
+                       if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
+                               i_getch(input); /* eat second ')' */
+                               break;
+                       }
+               }
+               o_addchr(dest, ch);
+               //bb_error_msg("%s:o_addchr('%c')", __func__, ch);
+               if (ch == '(' || ch == '{') {
+                       ch = (ch == '(' ? ')' : '}');
+                       if (!add_till_closing_bracket(dest, input, ch))
+                               return 0;
+                       o_addchr(dest, ch);
+                       continue;
+               }
+               if (ch == '\'') {
+                       if (!add_till_single_quote(dest, input))
+                               return 0;
+                       o_addchr(dest, ch);
+                       continue;
+               }
+               if (ch == '"') {
+                       if (!add_till_double_quote(dest, input))
+                               return 0;
+                       o_addchr(dest, ch);
+                       continue;
+               }
+               if (ch == '`') {
+                       if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
+                               return 0;
+                       o_addchr(dest, ch);
+                       continue;
+               }
+               if (ch == '\\') {
+                       /* \x. Copy verbatim. Important for  \(, \) */
+                       ch = i_getch(input);
+                       if (ch == EOF) {
+                               syntax_error_unterm_ch(end_ch);
+                               return 0;
+                       }
+# if 0
+                       if (ch == '\n') {
+                               /* "backslash+newline", ignore both */
+                               o_delchr(dest); /* undo insertion of '\' */
+                               continue;
+                       }
+# endif
+                       o_addchr(dest, ch);
+                       //bb_error_msg("%s:o_addchr('%c') after '\\'", __func__, ch);
+                       continue;
+               }
+       }
+       debug_printf_parse("%s return '%s' ch:'%c'\n", __func__, dest->data, ch);
+       return ch;
+}
+#endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
+
+#if BASH_DOLLAR_SQUOTE
+/* Return code: 1 for "found and parsed", 0 for "seen something else" */
+# if BB_MMU
+#define parse_dollar_squote(as_string, dest, input) \
+       parse_dollar_squote(dest, input)
+#define as_string NULL
+# endif
+static int parse_dollar_squote(o_string *as_string, o_string *dest, struct in_str *input)
+{
+       int start;
+       int ch = i_peek_and_eat_bkslash_nl(input);  /* first character after the $ */
+       debug_printf_parse("parse_dollar_squote entered: ch='%c'\n", ch);
+       if (ch != '\'')
+               return 0;
+
+       dest->has_quoted_part = 1;
+       start = dest->length;
+
+       ch = i_getch(input); /* eat ' */
+       nommu_addchr(as_string, ch);
+       while (1) {
+               ch = i_getch(input);
+               nommu_addchr(as_string, ch);
+               if (ch == EOF) {
+                       syntax_error_unterm_ch('\'');
+                       return 0;
+               }
+               if (ch == '\'')
+                       break;
+               if (ch == SPECIAL_VAR_SYMBOL) {
+                       /* Convert raw ^C to corresponding special variable reference */
+                       o_addchr(dest, SPECIAL_VAR_SYMBOL);
+                       o_addchr(dest, SPECIAL_VAR_QUOTED_SVS);
+                       /* will addchr() another SPECIAL_VAR_SYMBOL (see after the if() block) */
+               } else if (ch == '\\') {
+                       static const char C_escapes[] ALIGN1 = "nrbtfav""x\\01234567";
+
+                       ch = i_getch(input);
+                       nommu_addchr(as_string, ch);
+                       if (strchr(C_escapes, ch)) {
+                               char buf[4];
+                               char *p = buf;
+                               int cnt = 2;
+
+                               buf[0] = ch;
+                               if ((unsigned char)(ch - '0') <= 7) { /* \ooo */
+                                       do {
+                                               ch = i_peek(input);
+                                               if ((unsigned char)(ch - '0') > 7)
+                                                       break;
+                                               *++p = ch = i_getch(input);
+                                               nommu_addchr(as_string, ch);
+                                       } while (--cnt != 0);
+                               } else if (ch == 'x') { /* \xHH */
+                                       do {
+                                               ch = i_peek(input);
+                                               if (!isxdigit(ch))
+                                                       break;
+                                               *++p = ch = i_getch(input);
+                                               nommu_addchr(as_string, ch);
+                                       } while (--cnt != 0);
+                                       if (cnt == 2) { /* \x but next char is "bad" */
+                                               ch = 'x';
+                                               goto unrecognized;
+                                       }
+                               } /* else simple seq like \\ or \t */
+                               *++p = '\0';
+                               p = buf;
+                               ch = bb_process_escape_sequence((void*)&p);
+                               //bb_error_msg("buf:'%s' ch:%x", buf, ch);
+                               if (ch == '\0')
+                                       continue; /* bash compat: $'...\0...' emits nothing */
+                       } else { /* unrecognized "\z": encode both chars unless ' or " */
+                               if (ch != '\'' && ch != '"') {
+ unrecognized:
+                                       o_addqchr(dest, '\\');
+                               }
+                       }
+               } /* if (\...) */
+               o_addqchr(dest, ch);
+       }
+
+       if (dest->length == start) {
+               /* $'', $'\0', $'\000\x00' and the like */
+               o_addchr(dest, SPECIAL_VAR_SYMBOL);
+               o_addchr(dest, SPECIAL_VAR_SYMBOL);
+       }
+
+       return 1;
+# undef as_string
+}
+#else
+# #define parse_dollar_squote(as_string, dest, input) 0
+#endif /* BASH_DOLLAR_SQUOTE */
+
+/* Return code: 0 for OK, 1 for syntax error */
+#if BB_MMU
+#define parse_dollar(as_string, dest, input, quote_mask) \
+       parse_dollar(dest, input, quote_mask)
+#define as_string NULL
+#endif
+static int parse_dollar(o_string *as_string,
+               o_string *dest,
+               struct in_str *input, unsigned char quote_mask)
+{
+       int ch = i_peek_and_eat_bkslash_nl(input);  /* first character after the $ */
+
+       debug_printf_parse("parse_dollar entered: ch='%c' quote_mask:0x%x\n", ch, quote_mask);
+       if (isalpha(ch)) {
+ make_var:
+               ch = i_getch(input);
+               nommu_addchr(as_string, ch);
+ /*make_var1:*/
+               o_addchr(dest, SPECIAL_VAR_SYMBOL);
+               while (1) {
+                       debug_printf_parse(": '%c'\n", ch);
+                       o_addchr(dest, ch | quote_mask);
+                       quote_mask = 0;
+                       ch = i_peek_and_eat_bkslash_nl(input);
+                       if (!isalnum(ch) && ch != '_') {
+                               /* End of variable name reached */
+                               break;
+                       }
+                       ch = i_getch(input);
+                       nommu_addchr(as_string, ch);
+               }
+               o_addchr(dest, SPECIAL_VAR_SYMBOL);
+       } else if (isdigit(ch)) {
+ make_one_char_var:
+               ch = i_getch(input);
+               nommu_addchr(as_string, ch);
+               o_addchr(dest, SPECIAL_VAR_SYMBOL);
+               debug_printf_parse(": '%c'\n", ch);
+               o_addchr(dest, ch | quote_mask);
+               o_addchr(dest, SPECIAL_VAR_SYMBOL);
+       } else switch (ch) {
+       case '$': /* pid */
+       case '!': /* last bg pid */
+       case '?': /* last exit code */
+       case '#': /* number of args */
+       case '*': /* args */
+       case '@': /* args */
+       case '-': /* $- option flags set by set builtin or shell options (-i etc) */
+               goto make_one_char_var;
+       case '{': {
+               char len_single_ch;
+
+               o_addchr(dest, SPECIAL_VAR_SYMBOL);
+
+               ch = i_getch(input); /* eat '{' */
+               nommu_addchr(as_string, ch);
+
+               ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
+               /* It should be ${?}, or ${#var},
+                * or even ${?+subst} - operator acting on a special variable,
+                * or the beginning of variable name.
+                */
+               if (ch == EOF
+                || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
+               ) {
+ bad_dollar_syntax:
+                       syntax_error_unterm_str("${name}");
+                       debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
+                       return 0;
+               }
+               nommu_addchr(as_string, ch);
+               len_single_ch = ch;
+               ch |= quote_mask;
+
+               /* It's possible to just call add_till_closing_bracket() at this point.
+                * However, this regresses some of our testsuite cases
+                * which check invalid constructs like ${%}.
+                * Oh well... let's check that the var name part is fine... */
+
+               if (isdigit(len_single_ch)
+                || (len_single_ch == '#' && isdigit(i_peek_and_eat_bkslash_nl(input)))
+               ) {
+                       /* Execution engine uses plain xatoi_positive()
+                        * to interpret ${NNN} and {#NNN},
+                        * check syntax here in the parser.
+                        * (bash does not support expressions in ${#NN},
+                        * e.g. ${#$var} and {#1:+WORD} are not supported).
+                        */
+                       unsigned cnt = 9; /* max 9 digits for ${NN} and 8 for {#NN} */
+                       while (1) {
+                               o_addchr(dest, ch);
+                               debug_printf_parse(": '%c'\n", ch);
+                               ch = i_getch_and_eat_bkslash_nl(input);
+                               nommu_addchr(as_string, ch);
+                               if (ch == '}')
+                                       break;
+                               if (--cnt == 0)
+                                       goto bad_dollar_syntax;
+                               if (len_single_ch != '#' && strchr(VAR_SUBST_OPS, ch))
+                                       /* ${NN<op>...} is valid */
+                                       goto eat_until_closing;
+                               if (!isdigit(ch))
+                                       goto bad_dollar_syntax;
+                       }
+               } else
+               while (1) {
+                       unsigned pos;
+
+                       o_addchr(dest, ch);
+                       debug_printf_parse(": '%c'\n", ch);
+
+                       ch = i_getch(input);
+                       nommu_addchr(as_string, ch);
+                       if (ch == '}')
+                               break;
+                       if (!isalnum(ch) && ch != '_') {
+                               unsigned end_ch;
+                               unsigned char last_ch;
+                               /* handle parameter expansions
+                                * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
+                                */
+                               if (!strchr(VAR_SUBST_OPS, ch)) { /* ${var<bad_char>... */
+                                       if (len_single_ch != '#'
+                                       /*|| !strchr(SPECIAL_VARS_STR, ch) - disallow errors like ${#+} ? */
+                                        || i_peek(input) != '}'
+                                       ) {
+                                               goto bad_dollar_syntax;
+                                       }
+                                       /* else: it's "length of C" ${#C} op,
+                                        * where C is a single char
+                                        * special var name, e.g. ${#!}.
+                                        */
+                               }
+ eat_until_closing:
+                               /* Eat everything until closing '}' (or ':') */
+                               end_ch = '}';
+                               if (BASH_SUBSTR
+                                && ch == ':'
+                                && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
+                               ) {
+                                       /* It's ${var:N[:M]} thing */
+                                       end_ch = '}' * 0x100 + ':';
+                               }
+                               if (BASH_PATTERN_SUBST
+                                && ch == '/'
+                               ) {
+                                       /* It's ${var/[/]pattern[/repl]} thing */
+                                       if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
+                                               i_getch(input);
+                                               nommu_addchr(as_string, '/');
+                                               ch = '\\';
+                                       }
+                                       end_ch = '}' * 0x100 + '/';
+                               }
+                               o_addchr(dest, ch);
+                               /* The pattern can't be empty.
+                                * IOW: if the first char after "${v//" is a slash,
+                                * it does not terminate the pattern - it's the first char of the pattern:
+                                *  v=/dev/ram; echo ${v////-}  prints -dev-ram (pattern is "/")
+                                *  v=/dev/ram; echo ${v///r/-} prints /dev-am  (pattern is "/r")
+                                */
+                               if (i_peek(input) == '/') {
+                                       o_addchr(dest, i_getch(input));
+                               }
+ again:
+                               if (!BB_MMU)
+                                       pos = dest->length;
+#if ENABLE_HUSH_DOLLAR_OPS
+                               last_ch = add_till_closing_bracket(dest, input, end_ch);
+                               if (last_ch == 0) /* error? */
+                                       return 0;
+#else
+# error Simple code to only allow ${var} is not implemented
+#endif
+                               if (as_string) {
+                                       o_addstr(as_string, dest->data + pos);
+                                       o_addchr(as_string, last_ch);
+                               }
+
+                               if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
+                                        && (end_ch & 0xff00)
+                               ) {
+                                       /* close the first block: */
+                                       o_addchr(dest, SPECIAL_VAR_SYMBOL);
+                                       /* while parsing N from ${var:N[:M]}
+                                        * or pattern from ${var/[/]pattern[/repl]} */
+                                       if ((end_ch & 0xff) == last_ch) {
+                                               /* got ':' or '/'- parse the rest */
+                                               end_ch = '}';
+                                               goto again;
+                                       }
+                                       /* got '}' */
+                                       if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
+                                               /* it's ${var:N} - emulate :999999999 */
+                                               o_addstr(dest, "999999999");
+                                       } /* else: it's ${var/[/]pattern} */
+                               }
+                               break;
+                       }
+                       len_single_ch = 0; /* it can't be ${#C} op */
+               }
+               o_addchr(dest, SPECIAL_VAR_SYMBOL);
+               break;
+       }
+#if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
+       case '(': {
+               unsigned pos;
+
+               ch = i_getch(input);
+               nommu_addchr(as_string, ch);
+# if ENABLE_FEATURE_SH_MATH
+               if (i_peek_and_eat_bkslash_nl(input) == '(') {
+                       ch = i_getch(input);
+                       nommu_addchr(as_string, ch);
+                       o_addchr(dest, SPECIAL_VAR_SYMBOL);
+                       o_addchr(dest, quote_mask | '+');
+                       if (!BB_MMU)
+                               pos = dest->length;
+                       if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
+                               return 0; /* error */
+                       if (as_string) {
+                               o_addstr(as_string, dest->data + pos);
+                               o_addchr(as_string, ')');
+                               o_addchr(as_string, ')');
+                       }
+                       o_addchr(dest, SPECIAL_VAR_SYMBOL);
+                       break;
+               }
+# endif
+# if ENABLE_HUSH_TICK
+               o_addchr(dest, SPECIAL_VAR_SYMBOL);
+               o_addchr(dest, quote_mask | '`');
+               if (!BB_MMU)
+                       pos = dest->length;
+               if (!add_till_closing_bracket(dest, input, ')'))
+                       return 0; /* error */
+               if (as_string) {
+                       o_addstr(as_string, dest->data + pos);
+                       o_addchr(as_string, ')');
+               }
+               o_addchr(dest, SPECIAL_VAR_SYMBOL);
+# endif
+               break;
+       }
+#endif
+       case '_':
+               goto make_var;
+#if 0
+       /* TODO: $_: */
+       /* $_ Shell or shell script name; or last argument of last command
+        * (if last command wasn't a pipe; if it was, bash sets $_ to "");
+        * but in command's env, set to full pathname used to invoke it */
+               ch = i_getch(input);
+               nommu_addchr(as_string, ch);
+               ch = i_peek_and_eat_bkslash_nl(input);
+               if (isalnum(ch)) { /* it's $_name or $_123 */
+                       ch = '_';
+                       goto make_var1;
+               }
+               /* else: it's $_ */
+#endif
+       default:
+               o_addQchr(dest, '$');
+       }
+       debug_printf_parse("parse_dollar return 1 (ok)\n");
+       return 1;
+#undef as_string
+}
+
+#if BB_MMU
+#define encode_string(as_string, dest, input, dquote_end) \
+       encode_string(dest, input, dquote_end)
+#define as_string NULL
+#endif
+static int encode_string(o_string *as_string,
+               o_string *dest,
+               struct in_str *input,
+               int dquote_end)
+{
+       int ch;
+       int next;
+
+ again:
+       ch = i_getch(input);
+       if (ch != EOF)
+               nommu_addchr(as_string, ch);
+       if (ch == dquote_end) { /* may be only '"' or EOF */
+               debug_printf_parse("encode_string return 1 (ok)\n");
+               return 1;
+       }
+       /* note: can't move it above ch == dquote_end check! */
+       if (ch == EOF) {
+               syntax_error_unterm_ch('"');
+               return 0; /* error */
+       }
+       next = '\0';
+       if (ch != '\n') {
+               next = i_peek(input);
+       }
+       debug_printf_parse("\" ch=%c (%d) escape=%d\n",
+                       ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
+       if (ch == '\\') {
+               if (next == EOF) {
+                       /* Testcase: in interactive shell a file with
+                        *  echo "unterminated string\<eof>
+                        * is sourced.
+                        */
+                       syntax_error_unterm_ch('"');
+                       return 0; /* error */
+               }
+               /* bash:
+                * "The backslash retains its special meaning [in "..."]
+                * only when followed by one of the following characters:
+                * $, `, ", \, or <newline>.  A double quote may be quoted
+                * within double quotes by preceding it with a backslash."
+                * NB: in (unquoted) heredoc, above does not apply to ",
+                * therefore we check for it by "next == dquote_end" cond.
+                */
+               if (next == dquote_end || strchr("$`\\\n", next)) {
+                       ch = i_getch(input); /* eat next */
+                       if (ch == '\n')
+                               goto again; /* skip \<newline> */
+               } /* else: ch remains == '\\', and we double it below: */
+               o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
+               nommu_addchr(as_string, ch);
+               goto again;
+       }
+       if (ch == '$') {
+               //if (parse_dollar_squote(as_string, dest, input))
+               //      goto again;
+               if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
+                       debug_printf_parse("encode_string return 0: "
+                                       "parse_dollar returned 0 (error)\n");
+                       return 0;
+               }
+               goto again;
+       }
+#if ENABLE_HUSH_TICK
+       if (ch == '`') {
+               //unsigned pos = dest->length;
+               o_addchr(dest, SPECIAL_VAR_SYMBOL);
+               o_addchr(dest, 0x80 | '`');
+               if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
+                       return 0; /* error */
+               o_addchr(dest, SPECIAL_VAR_SYMBOL);
+               //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
+               goto again;
+       }
+#endif
+       o_addQchr(dest, ch);
+       if (ch == SPECIAL_VAR_SYMBOL) {
+               /* Convert "^C" to corresponding special variable reference */
+               o_addchr(dest, SPECIAL_VAR_QUOTED_SVS);
+               o_addchr(dest, SPECIAL_VAR_SYMBOL);
+       }
+       goto again;
+#undef as_string
+}
+
+/*
+ * Scan input until EOF or end_trigger char.
+ * Return a list of pipes to execute, or NULL on EOF
+ * or if end_trigger character is met.
+ * On syntax error, exit if shell is not interactive,
+ * reset parsing machinery and start parsing anew,
+ * or return ERR_PTR.
+ */
+static struct pipe *parse_stream(char **pstring,
+               int *heredoc_cnt_ptr,
+               struct in_str *input,
+               int end_trigger)
+{
+       struct parse_context ctx;
+       int heredoc_cnt;
+
+       /* Single-quote triggers a bypass of the main loop until its mate is
+        * found.  When recursing, quote state is passed in via ctx.word.o_expflags.
+        */
+       debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
+                       end_trigger ? end_trigger : 'X');
+       debug_enter();
+
+       initialize_context(&ctx);
+
+       /* If very first arg is "" or '', ctx.word.data may end up NULL.
+        * Preventing this:
+        */
+       ctx.word.data = xzalloc(1); /* start as "", not as NULL */
+
+       /* We used to separate words on $IFS here. This was wrong.
+        * $IFS is used only for word splitting when $var is expanded,
+        * here we should use blank chars as separators, not $IFS
+        */
+
+       heredoc_cnt = 0;
+       while (1) {
+               const char *is_blank;
+               const char *is_special;
+               int ch;
+               int next;
+               int redir_fd;
+               redir_type redir_style;
+
+               ch = i_getch(input);
+               debug_printf_parse(": ch=%c (%d) escape=%d\n",
+                               ch, ch, !!(ctx.word.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
+               if (ch == EOF) {
+                       struct pipe *pi;
+
+                       if (heredoc_cnt) {
+                               syntax_error_unterm_str("here document");
+                               goto parse_error_exitcode1;
+                       }
+                       if (end_trigger == ')') {
+                               syntax_error_unterm_ch('(');
+                               goto parse_error_exitcode1;
+                       }
+                       if (end_trigger == '}') {
+                               syntax_error_unterm_ch('{');
+                               goto parse_error_exitcode1;
+                       }
+
+                       if (done_word(&ctx)) {
+                               goto parse_error_exitcode1;
+                       }
+                       o_free_and_set_NULL(&ctx.word);
+                       done_pipe(&ctx, PIPE_SEQ);
+                       pi = ctx.list_head;
+                       /* If we got nothing... */
+                       /* (this makes bare "&" cmd a no-op.
+                        * bash says: "syntax error near unexpected token '&'") */
+                       if (pi->num_cmds == 0
+                       IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
+                       ) {
+                               free_pipe_list(pi);
+                               pi = NULL;
+                       }
+#if !BB_MMU
+                       debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
+                       if (pstring)
+                               *pstring = ctx.as_string.data;
+                       else
+                               o_free(&ctx.as_string);
+#endif
+                       // heredoc_cnt must be 0 here anyway
+                       //if (heredoc_cnt_ptr)
+                       //      *heredoc_cnt_ptr = heredoc_cnt;
+                       debug_leave();
+                       debug_printf_heredoc("parse_stream return heredoc_cnt:%d\n", heredoc_cnt);
+                       debug_printf_parse("parse_stream return %p\n", pi);
+                       return pi;
+               }
+
+               /* Handle "'" and "\" first, as they won't play nice with
+                * i_peek_and_eat_bkslash_nl() anyway:
+                *   echo z\\
+                * and
+                *   echo '\
+                *   '
+                * would break.
+                */
+               if (ch == '\\') {
+                       ch = i_getch(input);
+                       if (ch == '\n')
+                               continue; /* drop \<newline>, get next char */
+                       nommu_addchr(&ctx.as_string, '\\');
+                       if (ch == SPECIAL_VAR_SYMBOL) {
+                               nommu_addchr(&ctx.as_string, ch);
+                               /* Convert \^C to corresponding special variable reference */
+                               goto case_SPECIAL_VAR_SYMBOL;
+                       }
+                       o_addchr(&ctx.word, '\\');
+                       if (ch == EOF) {
+                               /* Testcase: eval 'echo Ok\' */
+                               /* bash-4.3.43 was removing backslash,
+                                * but 4.4.19 retains it, most other shells too
+                                */
+                               continue; /* get next char */
+                       }
+                       /* Example: echo Hello \2>file
+                        * we need to know that word 2 is quoted
+                        */
+                       ctx.word.has_quoted_part = 1;
+                       nommu_addchr(&ctx.as_string, ch);
+                       o_addchr(&ctx.word, ch);
+                       continue; /* get next char */
+               }
+               nommu_addchr(&ctx.as_string, ch);
+               if (ch == '\'') {
+                       ctx.word.has_quoted_part = 1;
+                       next = i_getch(input);
+                       if (next == '\'' && !ctx.pending_redirect)
+                               goto insert_empty_quoted_str_marker;
+
+                       ch = next;
+                       while (1) {
+                               if (ch == EOF) {
+                                       syntax_error_unterm_ch('\'');
+                                       goto parse_error_exitcode1;
+                               }
+                               nommu_addchr(&ctx.as_string, ch);
+                               if (ch == '\'')
+                                       break;
+                               if (ch == SPECIAL_VAR_SYMBOL) {
+                                       /* Convert raw ^C to corresponding special variable reference */
+                                       o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL);
+                                       o_addchr(&ctx.word, SPECIAL_VAR_QUOTED_SVS);
+                               }
+                               o_addqchr(&ctx.word, ch);
+                               ch = i_getch(input);
+                       }
+                       continue; /* get next char */
+               }
+
+               next = '\0';
+               if (ch != '\n')
+                       next = i_peek_and_eat_bkslash_nl(input);
+
+               is_special = "{}<>&|();#" /* special outside of "str" */
+                               "$\"" IF_HUSH_TICK("`") /* always special */
+                               SPECIAL_VAR_SYMBOL_STR;
+#if defined(CMD_TEST2_SINGLEWORD_NOGLOB)
+               if (ctx.command->cmd_type == CMD_TEST2_SINGLEWORD_NOGLOB) {
+                       /* In [[ ]], {}<>&|() are not special */
+                       is_special += 8;
+               } else
+#endif
+               /* Are { and } special here? */
+               if (ctx.command->argv /* word [word]{... - non-special */
+                || ctx.word.length       /* word{... - non-special */
+                || ctx.word.has_quoted_part     /* ""{... - non-special */
+                || (next != ';'             /* }; - special */
+                   && next != ')'           /* }) - special */
+                   && next != '('           /* {( - special */
+                   && next != '&'           /* }& and }&& ... - special */
+                   && next != '|'           /* }|| ... - special */
+                   && !strchr(defifs, next) /* {word - non-special */
+                   )
+               ) {
+                       /* They are not special, skip "{}" */
+                       is_special += 2;
+               }
+               is_special = strchr(is_special, ch);
+               is_blank = strchr(defifs, ch);
+
+               if (!is_special && !is_blank) { /* ordinary char */
+ ordinary_char:
+                       o_addQchr(&ctx.word, ch);
+                       if ((ctx.is_assignment == MAYBE_ASSIGNMENT
+                           || ctx.is_assignment == WORD_IS_KEYWORD)
+                        && ch == '='
+                        && endofname(ctx.word.data)[0] == '='
+                       ) {
+                               ctx.is_assignment = DEFINITELY_ASSIGNMENT;
+                               debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]);
+                       }
+                       continue;
+               }
+
+               if (is_blank) {
+#if ENABLE_HUSH_LINENO_VAR
+/* Case:
+ * "while ...; do<whitespace><newline>
+ *     cmd ..."
+ * would think that "cmd" starts in <whitespace> -
+ * i.e., at the previous line.
+ * We need to skip all whitespace before newlines.
+ */
+                       while (ch != '\n') {
+                               next = i_peek(input);
+                               if (next != ' ' && next != '\t' && next != '\n')
+                                       break; /* next char is not ws */
+                               ch = i_getch(input);
+                       }
+                       /* ch == last eaten whitespace char */
+#endif
+                       if (done_word(&ctx)) {
+                               goto parse_error_exitcode1;
+                       }
+                       if (ch == '\n') {
+                               /* Is this a case when newline is simply ignored?
+                                * Some examples:
+                                * "cmd | <newline> cmd ..."
+                                * "case ... in <newline> word) ..."
+                                */
+                               if (IS_NULL_CMD(ctx.command)
+                                && ctx.word.length == 0
+                                && !ctx.word.has_quoted_part
+                                && heredoc_cnt == 0
+                               ) {
+                                       /* This newline can be ignored. But...
+                                        * Without check #1, interactive shell
+                                        * ignores even bare <newline>,
+                                        * and shows the continuation prompt:
+                                        * ps1_prompt$ <enter>
+                                        * ps2> _   <=== wrong, should be ps1
+                                        * Without check #2, "cmd & <newline>"
+                                        * is similarly mistreated.
+                                        * (BTW, this makes "cmd & cmd"
+                                        * and "cmd && cmd" non-orthogonal.
+                                        * Really, ask yourself, why
+                                        * "cmd && <newline>" doesn't start
+                                        * cmd but waits for more input?
+                                        * The only reason is that it might be
+                                        * a "cmd1 && <nl> cmd2 &" construct,
+                                        * cmd1 may need to run in BG).
+                                        */
+                                       struct pipe *pi = ctx.list_head;
+                                       if (pi->num_cmds != 0       /* check #1 */
+                                        && pi->followup != PIPE_BG /* check #2 */
+                                       ) {
+                                               continue;
+                                       }
+                               }
+                               /* Treat newline as a command separator. */
+                               done_pipe(&ctx, PIPE_SEQ);
+                               debug_printf_heredoc("heredoc_cnt:%d\n", heredoc_cnt);
+                               if (heredoc_cnt) {
+                                       heredoc_cnt = fetch_heredocs(&ctx.as_string, ctx.list_head, heredoc_cnt, input);
+                                       if (heredoc_cnt != 0)
+                                               goto parse_error_exitcode1;
+                               }
+                               ctx.is_assignment = MAYBE_ASSIGNMENT;
+                               debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]);
+                               ch = ';';
+                               /* note: if (is_blank) continue;
+                                * will still trigger for us */
+                       }
+               }
+
+               /* "cmd}" or "cmd }..." without semicolon or &:
+                * } is an ordinary char in this case, even inside { cmd; }
+                * Pathological example: { ""}; } should exec "}" cmd
+                */
+               if (ch == '}') {
+                       if (ctx.word.length != 0 /* word} */
+                        || ctx.word.has_quoted_part    /* ""} */
+                       ) {
+                               goto ordinary_char;
+                       }
+                       if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
+                               /* Generally, there should be semicolon: "cmd; }"
+                                * However, bash allows to omit it if "cmd" is
+                                * a group. Examples:
+                                * { { echo 1; } }
+                                * {(echo 1)}
+                                * { echo 0 >&2 | { echo 1; } }
+                                * { while false; do :; done }
+                                * { case a in b) ;; esac }
+                                */
+                               if (ctx.command->group)
+                                       goto term_group;
+                               goto ordinary_char;
+                       }
+                       if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
+                               /* Can't be an end of {cmd}, skip the check */
+                               goto skip_end_trigger;
+                       /* else: } does terminate a group */
+               }
+ term_group:
+               if (end_trigger && end_trigger == ch
+                && (ch != ';' || heredoc_cnt == 0)
+#if ENABLE_HUSH_CASE
+                && (ch != ')'
+                   || ctx.ctx_res_w != RES_MATCH
+                   || (!ctx.word.has_quoted_part && strcmp(ctx.word.data, "esac") == 0)
+                   )
+#endif
+               ) {
+                       if (done_word(&ctx)) {
+                               goto parse_error_exitcode1;
+                       }
+                       done_pipe(&ctx, PIPE_SEQ);
+                       ctx.is_assignment = MAYBE_ASSIGNMENT;
+                       debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]);
+                       /* Do we sit outside of any if's, loops or case's? */
+                       if (!HAS_KEYWORDS
+                       IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
+                       ) {
+                               o_free_and_set_NULL(&ctx.word);
+#if !BB_MMU
+                               debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
+                               if (pstring)
+                                       *pstring = ctx.as_string.data;
+                               else
+                                       o_free(&ctx.as_string);
+#endif
+                               if (ch != ';' && IS_NULL_PIPE(ctx.list_head)) {
+                                       /* Example: bare "{ }", "()" */
+                                       G.last_exitcode = 2; /* bash compat */
+                                       syntax_error_unexpected_ch(ch);
+                                       goto parse_error;
+                               }
+                               if (heredoc_cnt_ptr)
+                                       *heredoc_cnt_ptr = heredoc_cnt;
+                               debug_printf_heredoc("parse_stream return heredoc_cnt:%d\n", heredoc_cnt);
+                               debug_printf_parse("parse_stream return %p: "
+                                               "end_trigger char found\n",
+                                               ctx.list_head);
+                               debug_leave();
+                               return ctx.list_head;
+                       }
+               }
+
+               if (is_blank)
+                       continue;
+
+               /* Catch <, > before deciding whether this word is
+                * an assignment. a=1 2>z b=2: b=2 is still assignment */
+               switch (ch) {
+               case '>':
+                       redir_fd = redirect_opt_num(&ctx.word);
+                       if (done_word(&ctx)) {
+                               goto parse_error_exitcode1;
+                       }
+                       redir_style = REDIRECT_OVERWRITE;
+                       if (next == '>') {
+                               redir_style = REDIRECT_APPEND;
+                               ch = i_getch(input);
+                               nommu_addchr(&ctx.as_string, ch);
+                       }
+#if 0
+                       else if (next == '(') {
+                               syntax_error(">(process) not supported");
+                               goto parse_error_exitcode1;
+                       }
+#endif
+                       if (parse_redirect(&ctx, redir_fd, redir_style, input))
+                               goto parse_error_exitcode1;
+                       continue; /* get next char */
+               case '<':
+                       redir_fd = redirect_opt_num(&ctx.word);
+                       if (done_word(&ctx)) {
+                               goto parse_error_exitcode1;
+                       }
+                       redir_style = REDIRECT_INPUT;
+                       if (next == '<') {
+                               redir_style = REDIRECT_HEREDOC;
+                               heredoc_cnt++;
+                               debug_printf_heredoc("++heredoc_cnt=%d\n", heredoc_cnt);
+                               ch = i_getch(input);
+                               nommu_addchr(&ctx.as_string, ch);
+                       } else if (next == '>') {
+                               redir_style = REDIRECT_IO;
+                               ch = i_getch(input);
+                               nommu_addchr(&ctx.as_string, ch);
+                       }
+#if 0
+                       else if (next == '(') {
+                               syntax_error("<(process) not supported");
+                               goto parse_error_exitcode1;
+                       }
+#endif
+                       if (parse_redirect(&ctx, redir_fd, redir_style, input))
+                               goto parse_error_exitcode1;
+                       continue; /* get next char */
+               case '#':
+                       if (ctx.word.length == 0 && !ctx.word.has_quoted_part) {
+                               /* skip "#comment" */
+                               /* note: we do not add it to &ctx.as_string */
+/* TODO: in bash:
+ * comment inside $() goes to the next \n, even inside quoted string (!):
+ * cmd "$(cmd2 #comment)" - syntax error
+ * cmd "`cmd2 #comment`" - ok
+ * We accept both (comment ends where command subst ends, in both cases).
+ */
+                               while (1) {
+                                       ch = i_peek(input);
+                                       if (ch == '\n') {
+                                               nommu_addchr(&ctx.as_string, '\n');
+                                               break;
+                                       }
+                                       ch = i_getch(input);
+                                       if (ch == EOF)
+                                               break;
+                               }
+                               continue; /* get next char */
+                       }
+                       break;
+               }
+ skip_end_trigger:
+
+               if (ctx.is_assignment == MAYBE_ASSIGNMENT
+                /* check that we are not in word in "a=1 2>word b=1": */
+                && !ctx.pending_redirect
+               ) {
+                       /* ch is a special char and thus this word
+                        * cannot be an assignment */
+                       ctx.is_assignment = NOT_ASSIGNMENT;
+                       debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]);
+               }
+
+               /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
+
+               switch (ch) {
+               case_SPECIAL_VAR_SYMBOL:
+               case SPECIAL_VAR_SYMBOL:
+                       /* Convert raw ^C to corresponding special variable reference */
+                       o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL);
+                       o_addchr(&ctx.word, SPECIAL_VAR_QUOTED_SVS);
+                       /* fall through */
+               case '#':
+                       /* non-comment #: "echo a#b" etc */
+                       o_addchr(&ctx.word, ch);
+                       continue; /* get next char */
+               case '$':
+                       if (parse_dollar_squote(&ctx.as_string, &ctx.word, input))
+                               continue; /* get next char */
+                       if (!parse_dollar(&ctx.as_string, &ctx.word, input, /*quote_mask:*/ 0)) {
+                               debug_printf_parse("parse_stream parse error: "
+                                       "parse_dollar returned 0 (error)\n");
+                               goto parse_error_exitcode1;
+                       }
+                       continue; /* get next char */
+               case '"':
+                       ctx.word.has_quoted_part = 1;
+                       if (next == '"' && !ctx.pending_redirect) {
+                               i_getch(input); /* eat second " */
+ insert_empty_quoted_str_marker:
+                               nommu_addchr(&ctx.as_string, next);
+                               o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL);
+                               o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL);
+                               continue; /* get next char */
+                       }
+                       if (ctx.is_assignment == NOT_ASSIGNMENT)
+                               ctx.word.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
+                       if (!encode_string(&ctx.as_string, &ctx.word, input, '"'))
+                               goto parse_error_exitcode1;
+                       ctx.word.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
+                       continue; /* get next char */
+#if ENABLE_HUSH_TICK
+               case '`': {
+                       USE_FOR_NOMMU(unsigned pos;)
+
+                       o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL);
+                       o_addchr(&ctx.word, '`');
+                       USE_FOR_NOMMU(pos = ctx.word.length;)
+                       if (!add_till_backquote(&ctx.word, input, /*in_dquote:*/ 0))
+                               goto parse_error_exitcode1;
+# if !BB_MMU
+                       o_addstr(&ctx.as_string, ctx.word.data + pos);
+                       o_addchr(&ctx.as_string, '`');
+# endif
+                       o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL);
+                       //debug_printf_subst("SUBST RES3 '%s'\n", ctx.word.data + pos);
+                       continue; /* get next char */
+               }
+#endif
+               case ';':
+#if ENABLE_HUSH_CASE
+ case_semi:
+#endif
+                       if (done_word(&ctx)) {
+                               goto parse_error_exitcode1;
+                       }
+                       done_pipe(&ctx, PIPE_SEQ);
+#if ENABLE_HUSH_CASE
+                       /* Eat multiple semicolons, detect
+                        * whether it means something special */
+                       while (1) {
+                               ch = i_peek_and_eat_bkslash_nl(input);
+                               if (ch != ';')
+                                       break;
+                               ch = i_getch(input);
+                               nommu_addchr(&ctx.as_string, ch);
+                               if (ctx.ctx_res_w == RES_CASE_BODY) {
+                                       ctx.ctx_dsemicolon = 1;
+                                       ctx.ctx_res_w = RES_MATCH;
+                                       break;
+                               }
+                       }
+#endif
+ new_cmd:
+                       /* We just finished a cmd. New one may start
+                        * with an assignment */
+                       ctx.is_assignment = MAYBE_ASSIGNMENT;
+                       debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]);
+                       continue; /* get next char */
+               case '&':
+                       if (done_word(&ctx)) {
+                               goto parse_error_exitcode1;
+                       }
+                       if (next == '&') {
+                               ch = i_getch(input);
+                               nommu_addchr(&ctx.as_string, ch);
+                               done_pipe(&ctx, PIPE_AND);
+                       } else {
+                               done_pipe(&ctx, PIPE_BG);
+                       }
+                       goto new_cmd;
+               case '|':
+                       if (done_word(&ctx)) {
+                               goto parse_error_exitcode1;
+                       }
+#if ENABLE_HUSH_CASE
+                       if (ctx.ctx_res_w == RES_MATCH)
+                               break; /* we are in case's "word | word)" */
+#endif
+                       if (next == '|') { /* || */
+                               ch = i_getch(input);
+                               nommu_addchr(&ctx.as_string, ch);
+                               done_pipe(&ctx, PIPE_OR);
+                       } else {
+                               /* we could pick up a file descriptor choice here
+                                * with redirect_opt_num(), but bash doesn't do it.
+                                * "echo foo 2| cat" yields "foo 2". */
+                               done_command(&ctx);
+                       }
+                       goto new_cmd;
+               case '(':
+#if ENABLE_HUSH_CASE
+                       /* "case... in [(]word)..." - skip '(' */
+                       if (ctx.ctx_res_w == RES_MATCH
+                        && ctx.command->argv == NULL /* not (word|(... */
+                        && ctx.word.length == 0 /* not word(... */
+                        && ctx.word.has_quoted_part == 0 /* not ""(... */
+                       ) {
+                               continue; /* get next char */
+                       }
+#endif
+                       /* fall through */
+               case '{': {
+                       int n = parse_group(&ctx, input, ch);
+                       if (n < 0) {
+                               goto parse_error_exitcode1;
+                       }
+                       debug_printf_heredoc("parse_group done, needs heredocs:%d\n", n);
+                       heredoc_cnt += n;
+                       goto new_cmd;
+               }
+               case ')':
+#if ENABLE_HUSH_CASE
+                       if (ctx.ctx_res_w == RES_MATCH)
+                               goto case_semi;
+#endif
+               case '}':
+                       /* proper use of this character is caught by end_trigger:
+                        * if we see {, we call parse_group(..., end_trigger='}')
+                        * and it will match } earlier (not here). */
+                       G.last_exitcode = 2;
+                       syntax_error_unexpected_ch(ch);
+                       goto parse_error;
+               default:
+                       if (HUSH_DEBUG)
+                               bb_error_msg_and_die("BUG: unexpected %c", ch);
+               }
+       } /* while (1) */
+
+ parse_error_exitcode1:
+       G.last_exitcode = 1;
+ parse_error:
+       {
+               struct parse_context *pctx;
+               IF_HAS_KEYWORDS(struct parse_context *p2;)
+
+               /* Clean up allocated tree.
+                * Sample for finding leaks on syntax error recovery path.
+                * Run it from interactive shell, watch pmap `pidof hush`.
+                * while if false; then false; fi; do break; fi
+                * Samples to catch leaks at execution:
+                * while if (true | { true;}); then echo ok; fi; do break; done
+                * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
+                */
+               pctx = &ctx;
+               do {
+                       /* Update pipe/command counts,
+                        * otherwise freeing may miss some */
+                       done_pipe(pctx, PIPE_SEQ);
+                       debug_printf_clean("freeing list %p from ctx %p\n",
+                                       pctx->list_head, pctx);
+                       debug_print_tree(pctx->list_head, 0);
+                       free_pipe_list(pctx->list_head);
+                       debug_printf_clean("freed list %p\n", pctx->list_head);
+#if !BB_MMU
+                       o_free(&pctx->as_string);
+#endif
+                       IF_HAS_KEYWORDS(p2 = pctx->stack;)
+                       if (pctx != &ctx) {
+                               free(pctx);
+                       }
+                       IF_HAS_KEYWORDS(pctx = p2;)
+               } while (HAS_KEYWORDS && pctx);
+
+               o_free(&ctx.word);
+#if !BB_MMU
+               if (pstring)
+                       *pstring = NULL;
+#endif
+               debug_leave();
+               return ERR_PTR;
+       }
+}
+
+
+/*** Execution routines ***/
+
+/* Expansion can recurse, need forward decls: */
+#if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
+#define expand_string_to_string(str, EXP_flags, do_unbackslash) \
+       expand_string_to_string(str)
+#endif
+static char *expand_string_to_string(const char *str, int EXP_flags, int do_unbackslash);
+#if ENABLE_HUSH_TICK
+static int process_command_subs(o_string *dest, const char *s);
+#endif
+static int expand_vars_to_list(o_string *output, int n, char *arg);
+
+/* expand_strvec_to_strvec() takes a list of strings, expands
+ * all variable references within and returns a pointer to
+ * a list of expanded strings, possibly with larger number
+ * of strings. (Think VAR="a b"; echo $VAR).
+ * This new list is allocated as a single malloc block.
+ * NULL-terminated list of char* pointers is at the beginning of it,
+ * followed by strings themselves.
+ * Caller can deallocate entire list by single free(list). */
+
+/* A horde of its helpers come first: */
+
+static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
+{
+       while (--len >= 0) {
+               char c = *str++;
+
+#if ENABLE_HUSH_BRACE_EXPANSION
+               if (c == '{' || c == '}') {
+                       /* { -> \{, } -> \} */
+                       o_addchr(o, '\\');
+                       /* And now we want to add { or } and continue:
+                        *  o_addchr(o, c);
+                        *  continue;
+                        * luckily, just falling through achieves this.
+                        */
+               }
+#endif
+               o_addchr(o, c);
+               if (c == '\\') {
+                       /* \z -> \\\z; \<eol> -> \\<eol> */
+                       o_addchr(o, '\\');
+                       if (len) {
+                               len--;
+                               o_addchr(o, '\\');
+                               o_addchr(o, *str++);
+                       }
+               }
+       }
+}
+
+/* Store given string, finalizing the word and starting new one whenever
+ * we encounter IFS char(s). This is used for expanding variable values.
+ * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
+ * Return in output->ended_in_ifs:
+ * 1 - ended with IFS char, else 0 (this includes case of empty str).
+ */
+static int expand_on_ifs(o_string *output, int n, const char *str)
+{
+       int last_is_ifs = 0;
+
+       while (1) {
+               int word_len;
+
+               if (!*str)  /* EOL - do not finalize word */
+                       break;
+               word_len = strcspn(str, G.ifs);
+               if (word_len) {
+                       /* We have WORD_LEN leading non-IFS chars */
+                       if (!(output->o_expflags & EXP_FLAG_GLOB)) {
+                               o_addblock(output, str, word_len);
+                       } else {
+                               /* Protect backslashes against globbing up :)
+                                * Example: "v='\*'; echo b$v" prints "b\*"
+                                * (and does not try to glob on "*")
+                                */
+                               o_addblock_duplicate_backslash(output, str, word_len);
+                               /*/ Why can't we do it easier? */
+                               /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
+                               /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
+                       }
+                       last_is_ifs = 0;
+                       str += word_len;
+                       if (!*str)  /* EOL - do not finalize word */
+                               break;
+               }
+
+               /* We know str here points to at least one IFS char */
+               last_is_ifs = 1;
+               str += strspn(str, G.ifs_whitespace); /* skip IFS whitespace chars */
+               if (!*str)  /* EOL - do not finalize word */
+                       break;
+
+               if (G.ifs_whitespace != G.ifs /* usually false ($IFS is usually all whitespace), */
+                && strchr(G.ifs, *str)       /* the second check would fail */
+               ) {
+                       /* This is a non-whitespace $IFS char */
+                       /* Skip it and IFS whitespace chars, start new word */
+                       str++;
+                       str += strspn(str, G.ifs_whitespace);
+                       goto new_word;
+               }
+
+               /* Start new word... but not always! */
+               /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
+               if (output->has_quoted_part
+               /*
+                * Case "v=' a'; echo $v":
+                * here nothing precedes the space in $v expansion,
+                * therefore we should not finish the word
+                * (IOW: if there *is* word to finalize, only then do it):
+                * It's okay if this accesses the byte before first argv[]:
+                * past call to o_save_ptr() cleared it to zero byte
+                * (grep for -prev-ifs-check-).
+                */
+                || output->data[output->length - 1]
+               ) {
+ new_word:
+                       o_addchr(output, '\0');
+                       debug_print_list("expand_on_ifs", output, n);
+                       n = o_save_ptr(output, n);
+               }
+       }
+
+       output->ended_in_ifs = last_is_ifs;
+       debug_print_list("expand_on_ifs[1]", output, n);
+       return n;
+}
+
+/* Helper to expand $((...)) and heredoc body. These act as if
+ * they are in double quotes, with the exception that they are not :).
+ * Just the rules are similar: "expand only $var and `cmd`"
+ *
+ * Returns malloced string.
+ * As an optimization, we return NULL if expansion is not needed.
+ */
+static char *encode_then_expand_string(const char *str)
+{
+       char *exp_str;
+       struct in_str input;
+       o_string dest = NULL_O_STRING;
+       const char *cp;
+
+       cp = str;
+       for (;;) {
+               if (!*cp) return NULL; /* string has no special chars */
+               if (*cp == '$') break;
+               if (*cp == '\\') break;
+#if ENABLE_HUSH_TICK
+               if (*cp == '`') break;
+#endif
+               cp++;
+       }
+
+       /* We need to expand. Example:
+        * echo $(($a + `echo 1`)) $((1 + $((2)) ))
+        */
+       setup_string_in_str(&input, str);
+       encode_string(NULL, &dest, &input, EOF);
+//TODO: error check (encode_string returns 0 on error)?
+       //bb_error_msg("'%s' -> '%s'", str, dest.data);
+       exp_str = expand_string_to_string(dest.data,
+                       EXP_FLAG_ESC_GLOB_CHARS,
+                       /*unbackslash:*/ 1
+       );
+       //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
+       o_free(&dest);
+       return exp_str;
+}
+
+static const char *first_special_char_in_vararg(const char *cp)
+{
+       for (;;) {
+               if (!*cp) return NULL; /* string has no special chars */
+               if (*cp == '$') return cp;
+               if (*cp == '\\') return cp;
+               if (*cp == '\'') return cp;
+               if (*cp == '"') return cp;
+#if ENABLE_HUSH_TICK
+               if (*cp == '`') return cp;
+#endif
+               /* dquoted "${x:+ARG}" should not glob, therefore
+                * '*' et al require some non-literal processing: */
+               if (*cp == '*') return cp;
+               if (*cp == '?') return cp;
+               if (*cp == '[') return cp;
+               cp++;
+       }
+}
+
+/* Expanding ARG in ${var#ARG}, ${var%ARG}, or ${var/ARG/ARG}.
+ * These can contain single- and double-quoted strings,
+ * and treated as if the ARG string is initially unquoted. IOW:
+ * ${var#ARG} and "${var#ARG}" treat ARG the same (ARG can even be
+ * a dquoted string: "${var#"zz"}"), the difference only comes later
+ * (word splitting and globbing of the ${var...} result).
+ */
+#if !BASH_PATTERN_SUBST
+#define encode_then_expand_vararg(str, handle_squotes, do_unbackslash) \
+       encode_then_expand_vararg(str, handle_squotes)
+#endif
+static char *encode_then_expand_vararg(const char *str, int handle_squotes, int do_unbackslash)
+{
+#if !BASH_PATTERN_SUBST && ENABLE_HUSH_CASE
+       const int do_unbackslash = 0;
+#endif
+       char *exp_str;
+       struct in_str input;
+       o_string dest = NULL_O_STRING;
+
+       if (!first_special_char_in_vararg(str)) {
+               /* string has no special chars */
+               return NULL;
+       }
+
+       setup_string_in_str(&input, str);
+       dest.data = xzalloc(1); /* start as "", not as NULL */
+       exp_str = NULL;
+
+       for (;;) {
+               int ch;
+
+               ch = i_getch(&input);
+               debug_printf_parse("%s: ch=%c (%d) escape=%d\n",
+                               __func__, ch, ch, !!dest.o_expflags);
+
+               if (!dest.o_expflags) {
+                       if (ch == EOF)
+                               break;
+                       if (handle_squotes && ch == '\'') {
+                               if (!add_till_single_quote_dquoted(&dest, &input))
+                                       goto ret; /* error */
+                               continue;
+                       }
+               }
+               if (ch == EOF) {
+                       syntax_error_unterm_ch('"');
+                       goto ret; /* error */
+               }
+               if (ch == '"') {
+                       dest.o_expflags ^= EXP_FLAG_ESC_GLOB_CHARS;
+                       continue;
+               }
+               if (ch == '\\') {
+                       ch = i_getch(&input);
+                       if (ch == EOF) {
+//example? error message?      syntax_error_unterm_ch('"');
+                               debug_printf_parse("%s: error: \\<eof>\n", __func__);
+                               goto ret;
+                       }
+                       o_addqchr(&dest, ch);
+                       continue;
+               }
+               if (ch == '$') {
+                       if (parse_dollar_squote(NULL, &dest, &input))
+                               continue;
+                       if (!parse_dollar(NULL, &dest, &input, /*quote_mask:*/ 0x80)) {
+                               debug_printf_parse("%s: error: parse_dollar returned 0 (error)\n", __func__);
+                               goto ret;
+                       }
+                       continue;
+               }
+#if ENABLE_HUSH_TICK
+               if (ch == '`') {
+                       //unsigned pos = dest->length;
+                       o_addchr(&dest, SPECIAL_VAR_SYMBOL);
+                       o_addchr(&dest, 0x80 | '`');
+                       if (!add_till_backquote(&dest, &input,
+                                       /*in_dquote:*/ dest.o_expflags /* nonzero if EXP_FLAG_ESC_GLOB_CHARS set */
+                               )
+                       ) {
+                               goto ret; /* error */
+                       }
+                       o_addchr(&dest, SPECIAL_VAR_SYMBOL);
+                       //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
+                       continue;
+               }
+#endif
+               o_addQchr(&dest, ch);
+       } /* for (;;) */
+
+       debug_printf_parse("encode: '%s' -> '%s'\n", str, dest.data);
+       exp_str = expand_string_to_string(dest.data,
+                       do_unbackslash ? EXP_FLAG_ESC_GLOB_CHARS : 0,
+                       do_unbackslash
+       );
+ ret:
+       debug_printf_parse("expand: '%s' -> '%s'\n", dest.data, exp_str);
+       o_free(&dest);
+       return exp_str;
+}
+
+/* Expanding ARG in ${var+ARG}, ${var-ARG}
+ */
+static int encode_then_append_var_plusminus(o_string *output, int n,
+               char *str, int dquoted)
+{
+       struct in_str input;
+       o_string dest = NULL_O_STRING;
+
+       if (!first_special_char_in_vararg(str)
+        && '\0' == str[strcspn(str, G.ifs)]
+       ) {
+               /* string has no special chars
+                * && string has no $IFS chars
+                */
+               if (dquoted) {
+                       /* Prints 1 (quoted expansion is a "" word, not nothing):
+                        * set -- "${notexist-}"; echo $#
+                        */
+                       output->has_quoted_part = 1;
+               }
+               return expand_vars_to_list(output, n, str);
+       }
+
+       setup_string_in_str(&input, str);
+
+       for (;;) {
+               int ch;
+
+               ch = i_getch(&input);
+               debug_printf_parse("%s: ch=%c (%d) escape=%x\n",
+                               __func__, ch, ch, dest.o_expflags);
+
+               if (!dest.o_expflags) {
+                       if (ch == EOF)
+                               break;
+                       if (!dquoted && strchr(G.ifs, ch)) {
+                               /* PREFIX${x:d${e}f ...} and we met space: expand "d${e}f" and start new word.
+                                * do not assume we are at the start of the word (PREFIX above).
+                                */
+                               if (dest.data) {
+                                       n = expand_vars_to_list(output, n, dest.data);
+                                       o_free_and_set_NULL(&dest);
+                                       o_addchr(output, '\0');
+                                       n = o_save_ptr(output, n); /* create next word */
+                               } else
+                               if (output->length != o_get_last_ptr(output, n)
+                                || output->has_quoted_part
+                               ) {
+                                       /* For these cases:
+                                        * f() { for i; do echo "|$i|"; done; }; x=x
+                                        * f a${x:+ }b  # 1st condition
+                                        * |a|
+                                        * |b|
+                                        * f ""${x:+ }b  # 2nd condition
+                                        * ||
+                                        * |b|
+                                        */
+                                       o_addchr(output, '\0');
+                                       n = o_save_ptr(output, n); /* create next word */
+                               }
+                               continue;
+                       }
+                       if (!dquoted && ch == '\'') {
+                               if (!add_till_single_quote_dquoted(&dest, &input))
+                                       goto ret; /* error */
+                               o_addchr(&dest, SPECIAL_VAR_SYMBOL);
+                               o_addchr(&dest, SPECIAL_VAR_SYMBOL);
+                               continue;
+                       }
+               }
+               if (ch == EOF) {
+                       syntax_error_unterm_ch('"');
+                       goto ret; /* error */
+               }
+               if (ch == '"') {
+                       dest.o_expflags ^= EXP_FLAG_ESC_GLOB_CHARS;
+                       if (dest.o_expflags) {
+                               o_addchr(&dest, SPECIAL_VAR_SYMBOL);
+                               o_addchr(&dest, SPECIAL_VAR_SYMBOL);
+                       }
+                       continue;
+               }
+               if (ch == '\\') {
+                       ch = i_getch(&input);
+                       if (ch == EOF) {
+//example? error message?      syntax_error_unterm_ch('"');
+                               debug_printf_parse("%s: error: \\<eof>\n", __func__);
+                               goto ret;
+                       }
+                       o_addqchr(&dest, ch);
+                       continue;
+               }
+               if (ch == '$') {
+                       if (!parse_dollar(NULL, &dest, &input, /*quote_mask:*/ (dest.o_expflags || dquoted) ? 0x80 : 0)) {
+                               debug_printf_parse("%s: error: parse_dollar returned 0 (error)\n", __func__);
+                               goto ret;
+                       }
+                       continue;
+               }
+#if ENABLE_HUSH_TICK
+               if (ch == '`') {
+                       //unsigned pos = dest->length;
+                       o_addchr(&dest, SPECIAL_VAR_SYMBOL);
+                       o_addchr(&dest, (dest.o_expflags || dquoted) ? 0x80 | '`' : '`');
+                       if (!add_till_backquote(&dest, &input,
+                                       /*in_dquote:*/ dest.o_expflags /* nonzero if EXP_FLAG_ESC_GLOB_CHARS set */
+                               )
+                       ) {
+                               goto ret; /* error */
+                       }
+                       o_addchr(&dest, SPECIAL_VAR_SYMBOL);
+                       //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
+                       continue;
+               }
+#endif
+               if (dquoted) {
+                       /* Always glob-protect if in dquotes:
+                        * x=x; echo "${x:+/bin/c*}" - prints: /bin/c*
+                        * x=x; echo "${x:+"/bin/c*"}" - prints: /bin/c*
+                        */
+                       o_addqchr(&dest, ch);
+               } else {
+                       /* Glob-protect only if char is quoted:
+                        * x=x; echo ${x:+/bin/c*} - prints many filenames
+                        * x=x; echo ${x:+"/bin/c*"} - prints: /bin/c*
+                        */
+                       o_addQchr(&dest, ch);
+               }
+       } /* for (;;) */
+
+       if (dest.data) {
+               n = expand_vars_to_list(output, n, dest.data);
+       }
+ ret:
+       o_free(&dest);
+       return n;
+}
+
+#if ENABLE_FEATURE_SH_MATH
+static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
+{
+       arith_state_t math_state;
+       arith_t res;
+       char *exp_str;
+
+       math_state.lookupvar = get_local_var_value;
+       math_state.setvar = set_local_var_from_halves;
+       //math_state.endofname = endofname;
+       exp_str = encode_then_expand_string(arg);
+       res = arith(&math_state, exp_str ? exp_str : arg);
+       free(exp_str);
+       if (errmsg_p)
+               *errmsg_p = math_state.errmsg;
+       if (math_state.errmsg)
+               msg_and_die_if_script(math_state.errmsg);
+       return res;
+}
+#endif
+
+#if BASH_PATTERN_SUBST
+/* ${var/[/]pattern[/repl]} helpers */
+static char *strstr_pattern(char *val, const char *pattern, int *size)
+{
+       int sz = strcspn(pattern, "*?[\\");
+       if (pattern[sz] == '\0') {
+               /* Optimization for trivial patterns.
+                * Testcase for very slow replace (performs about 22k replaces):
+                * x=::::::::::::::::::::::
+                * x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;echo ${#x}
+                * echo "${x//:/|}"
+                */
+               *size = sz;
+               return strstr(val, pattern);
+       }
+
+       while (1) {
+               char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
+               debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
+               if (end) {
+                       *size = end - val;
+                       return val;
+               }
+               if (*val == '\0')
+                       return NULL;
+               /* Optimization: if "*pat" did not match the start of "string",
+                * we know that "tring", "ring" etc will not match too:
+                */
+               if (pattern[0] == '*')
+                       return NULL;
+               val++;
+       }
+}
+static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
+{
+       char *result = NULL;
+       unsigned res_len = 0;
+       unsigned repl_len = strlen(repl);
+
+       /* Null pattern never matches, including if "var" is empty */
+       if (!pattern[0])
+               return result; /* NULL, no replaces happened */
+
+       while (1) {
+               int size;
+               char *s = strstr_pattern(val, pattern, &size);
+               if (!s)
+                       break;
+
+               result = xrealloc(result, res_len + (s - val) + repl_len + 1);
+               strcpy(mempcpy(result + res_len, val, s - val), repl);
+               res_len += (s - val) + repl_len;
+               debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
+
+               val = s + size;
+               if (exp_op == '/')
+                       break;
+       }
+       if (*val && result) {
+               result = xrealloc(result, res_len + strlen(val) + 1);
+               strcpy(result + res_len, val);
+               debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
+       }
+       debug_printf_varexp("result:'%s'\n", result);
+       return result;
+}
+#endif /* BASH_PATTERN_SUBST */
+
+static int append_str_maybe_ifs_split(o_string *output, int n,
+               int first_ch, const char *val)
+{
+       if (!(first_ch & 0x80)) { /* unquoted $VAR */
+               debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
+                               !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
+               if (val && val[0])
+                       n = expand_on_ifs(output, n, val);
+       } else { /* quoted "$VAR" */
+               output->has_quoted_part = 1;
+               debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
+                               !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
+               if (val && val[0])
+                       o_addQstr(output, val);
+       }
+       return n;
+}
+
+/* Handle <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
+ */
+static NOINLINE int expand_one_var(o_string *output, int n,
+               int first_ch, char *arg, char **pp)
+{
+       const char *val;
+       char *to_be_freed;
+       char *p;
+       char *var;
+       char exp_op;
+       char exp_save = exp_save; /* for compiler */
+       char *exp_saveptr; /* points to expansion operator */
+       char *exp_word = exp_word; /* for compiler */
+       char arg0;
+
+       val = NULL;
+       to_be_freed = NULL;
+       p = *pp;
+       *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
+       var = arg;
+       exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
+       arg0 = arg[0];
+       arg[0] = (arg0 & 0x7f);
+       exp_op = 0;
+
+       if (arg[0] == '#' && arg[1] /* ${#...} but not ${#} */
+        && (!exp_saveptr               /* and ( not(${#<op_char>...}) */
+           || (arg[2] == '\0' && strchr(SPECIAL_VARS_STR, arg[1])) /* or ${#C} "len of $C" ) */
+           )           /* NB: skipping ^^^specvar check mishandles ${#::2} */
+       ) {
+               /* It must be length operator: ${#var} */
+               var++;
+               exp_op = 'L';
+       } else {
+               /* Maybe handle parameter expansion */
+               if (exp_saveptr /* if 2nd char is one of expansion operators */
+                && strchr(NUMERIC_SPECVARS_STR, arg[0]) /* 1st char is special variable */
+               ) {
+                       /* ${?:0}, ${#[:]%0} etc */
+                       exp_saveptr = var + 1;
+               } else {
+                       /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
+                       exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
+               }
+               exp_op = exp_save = *exp_saveptr;
+               if (exp_op) {
+                       exp_word = exp_saveptr + 1;
+                       if (exp_op == ':') {
+                               exp_op = *exp_word++;
+//TODO: try ${var:} and ${var:bogus} in non-bash config
+                               if (BASH_SUBSTR
+                                && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
+                               ) {
+                                       /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
+                                       exp_op = ':';
+                                       exp_word--;
+                               }
+                       }
+                       *exp_saveptr = '\0';
+               } /* else: it's not an expansion op, but bare ${var} */
+       }
+
+       /* Look up the variable in question */
+       if (isdigit(var[0])) {
+               /* parse_dollar should have vetted var for us */
+               int nn = xatoi_positive(var);
+               if (nn < G.global_argc)
+                       val = G.global_argv[nn];
+               /* else val remains NULL: $N with too big N */
+       } else {
+               switch (var[0]) {
+               case '$': /* pid */
+                       val = utoa(G.root_pid);
+                       break;
+               case '!': /* bg pid */
+                       val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
+                       break;
+               case '?': /* exitcode */
+                       val = utoa(G.last_exitcode);
+                       break;
+               case '#': /* argc */
+                       val = utoa(G.global_argc ? G.global_argc-1 : 0);
+                       break;
+               case '-': { /* active options */
+                       /* Check set_mode() to see what option chars we support */
+                       char *cp;
+                       val = cp = G.optstring_buf;
+                       if (G.o_opt[OPT_O_ERREXIT])
+                               *cp++ = 'e';
+                       if (G_interactive_fd)
+                               *cp++ = 'i';
+                       if (G_x_mode)
+                               *cp++ = 'x';
+                       /* If G.o_opt[OPT_O_NOEXEC] is true,
+                        * commands read but are not executed,
+                        * so $- can not execute too, 'n' is never seen in $-.
+                        */
+                       if (G.opt_c)
+                               *cp++ = 'c';
+                       if (G.opt_s)
+                               *cp++ = 's';
+                       *cp = '\0';
+                       break;
+               }
+               default:
+                       val = get_local_var_value(var);
+               }
+       }
+
+       /* Handle any expansions */
+       if (exp_op == 'L') {
+               reinit_unicode_for_hush();
+               debug_printf_expand("expand: length(%s)=", val);
+               val = utoa(val ? unicode_strlen(val) : 0);
+               debug_printf_expand("%s\n", val);
+       } else if (exp_op) {
+               if (exp_op == '%' || exp_op == '#') {
+                       /* Standard-mandated substring removal ops:
+                        * ${parameter%word} - remove smallest suffix pattern
+                        * ${parameter%%word} - remove largest suffix pattern
+                        * ${parameter#word} - remove smallest prefix pattern
+                        * ${parameter##word} - remove largest prefix pattern
+                        *
+                        * Word is expanded to produce a glob pattern.
+                        * Then var's value is matched to it and matching part removed.
+                        */
+                       /* bash compat: if x is "" and no shrinking of it is possible,
+                        * inner ${...} is not evaluated. Example:
+                        *  unset b; : ${a%${b=B}}; echo $b
+                        * assignment b=B only happens if $a is not "".
+                        */
+                       if (val && val[0]) {
+                               char *t;
+                               char *exp_exp_word;
+                               char *loc;
+                               unsigned scan_flags = pick_scan(exp_op, *exp_word);
+                               if (exp_op == *exp_word)  /* ## or %% */
+                                       exp_word++;
+                               debug_printf_expand("expand: exp_word:'%s'\n", exp_word);
+                               exp_exp_word = encode_then_expand_vararg(exp_word, /*handle_squotes:*/ 1, /*unbackslash:*/ 0);
+                               if (exp_exp_word)
+                                       exp_word = exp_exp_word;
+                               debug_printf_expand("expand: exp_word:'%s'\n", exp_word);
+                               /*
+                                * HACK ALERT. We depend here on the fact that
+                                * G.global_argv and results of utoa and get_local_var_value
+                                * are actually in writable memory:
+                                * scan_and_match momentarily stores NULs there.
+                                */
+                               t = (char*)val;
+                               loc = scan_and_match(t, exp_word, scan_flags);
+                               debug_printf_expand("op:%c str:'%s' pat:'%s' res:'%s'\n", exp_op, t, exp_word, loc);
+                               free(exp_exp_word);
+                               if (loc) { /* match was found */
+                                       if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
+                                               val = loc; /* take right part */
+                                       else /* %[%] */
+                                               val = to_be_freed = xstrndup(val, loc - val); /* left */
+                               }
+                       }
+               }
+#if BASH_PATTERN_SUBST
+               else if (exp_op == '/' || exp_op == '\\') {
+                       /* It's ${var/[/]pattern[/repl]} thing.
+                        * Note that in encoded form it has TWO parts:
+                        * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
+                        * and if // is used, it is encoded as \:
+                        * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
+                        */
+                       /* bash compat: if var is "", both pattern and repl
+                        * are still evaluated, if it is unset, then not:
+                        * unset b; a=; : ${a/z/${b=3}}; echo $b      # b=3
+                        * unset b; unset a; : ${a/z/${b=3}}; echo $b # b not set
+                        */
+                       if (val /*&& val[0]*/) {
+                               /* pattern uses non-standard expansion.
+                                * repl should be unbackslashed and globbed
+                                * by the usual expansion rules:
+                                *  >az >bz
+                                *  v='a bz'; echo "${v/a*z/a*z}" #prints "a*z"
+                                *  v='a bz'; echo "${v/a*z/\z}"  #prints "z"
+                                *  v='a bz'; echo ${v/a*z/a*z}   #prints "az"
+                                *  v='a bz'; echo ${v/a*z/\z}    #prints "z"
+                                * (note that a*z _pattern_ is never globbed!)
+                                */
+                               char *pattern, *repl, *t;
+                               pattern = encode_then_expand_vararg(exp_word, /*handle_squotes:*/ 1, /*unbackslash:*/ 0);
+                               if (!pattern)
+                                       pattern = xstrdup(exp_word);
+                               debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
+                               *p++ = SPECIAL_VAR_SYMBOL;
+                               exp_word = p;
+                               p = strchr(p, SPECIAL_VAR_SYMBOL);
+                               *p = '\0';
+                               repl = encode_then_expand_vararg(exp_word, /*handle_squotes:*/ 1, /*unbackslash:*/ 1);
+                               debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
+                               /* HACK ALERT. We depend here on the fact that
+                                * G.global_argv and results of utoa and get_local_var_value
+                                * are actually in writable memory:
+                                * replace_pattern momentarily stores NULs there. */
+                               t = (char*)val;
+                               to_be_freed = replace_pattern(t,
+                                               pattern,
+                                               (repl ? repl : exp_word),
+                                               exp_op);
+                               if (to_be_freed) /* at least one replace happened */
+                                       val = to_be_freed;
+                               free(pattern);
+                               free(repl);
+                       } else {
+                               /* Unset variable always gives nothing */
+                               //  a=; echo ${a/*/w}      # "w"
+                               //  unset a; echo ${a/*/w} # ""
+                               /* Just skip "replace" part */
+                               *p++ = SPECIAL_VAR_SYMBOL;
+                               p = strchr(p, SPECIAL_VAR_SYMBOL);
+                               *p = '\0';
+                       }
+               }
+#endif /* BASH_PATTERN_SUBST */
+               else if (exp_op == ':') {
+#if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
+                       /* It's ${var:N[:M]} bashism.
+                        * Note that in encoded form it has TWO parts:
+                        * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
+                        */
+                       arith_t beg, len;
+                       unsigned vallen;
+                       const char *errmsg;
+
+                       beg = expand_and_evaluate_arith(exp_word, &errmsg);
+                       if (errmsg)
+                               goto empty_result;
+                       debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
+                       *p++ = SPECIAL_VAR_SYMBOL;
+                       exp_word = p;
+                       p = strchr(p, SPECIAL_VAR_SYMBOL);
+                       *p = '\0';
+                       vallen = val ? strlen(val) : 0;
+                       if (beg < 0) {
+                               /* negative beg counts from the end */
+                               beg = (arith_t)vallen + beg;
+                       }
+                       /* If expansion will be empty, do not even evaluate len */
+                       if (!val || beg < 0 || beg > vallen) {
+                               /* Why > vallen, not >=? bash:
+                                * unset b; a=ab; : ${a:2:${b=3}}; echo $b  # "", b=3 (!!!)
+                                * unset b; a=a; : ${a:2:${b=3}}; echo $b   # "", b not set
+                                */
+                               goto empty_result;
+                       }
+                       len = expand_and_evaluate_arith(exp_word, &errmsg);
+                       if (errmsg)
+                               goto empty_result;
+                       debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
+                       debug_printf_varexp("from val:'%s'\n", val);
+                       if (len < 0) {
+                               /* in bash, len=-n means strlen()-n */
+                               len = (arith_t)vallen - beg + len;
+                               if (len < 0) /* bash compat */
+                                       msg_and_die_if_script("%s: substring expression < 0", var);
+                       }
+                       if (len <= 0 || !val /*|| beg >= vallen*/) {
+ empty_result:
+                               val = NULL;
+                       } else {
+                               /* Paranoia. What if user entered 9999999999999
+                                * which fits in arith_t but not int? */
+                               if (len > INT_MAX)
+                                       len = INT_MAX;
+                               val = to_be_freed = xstrndup(val + beg, len);
+                       }
+                       debug_printf_varexp("val:'%s'\n", val);
+#else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */
+                       msg_and_die_if_script("malformed ${%s:...}", var);
+                       val = NULL;
+#endif
+               } else { /* one of "-=+?" */
+                       /* Standard-mandated substitution ops:
+                        * ${var?word} - indicate error if unset
+                        *      If var is unset, word (or a message indicating it is unset
+                        *      if word is null) is written to standard error
+                        *      and the shell exits with a non-zero exit status.
+                        *      Otherwise, the value of var is substituted.
+                        * ${var-word} - use default value
+                        *      If var is unset, word is substituted.
+                        * ${var=word} - assign and use default value
+                        *      If var is unset, word is assigned to var.
+                        *      In all cases, final value of var is substituted.
+                        * ${var+word} - use alternative value
+                        *      If var is unset, null is substituted.
+                        *      Otherwise, word is substituted.
+                        *
+                        * Word is subjected to tilde expansion, parameter expansion,
+                        * command substitution, and arithmetic expansion.
+                        * If word is not needed, it is not expanded.
+                        *
+                        * Colon forms (${var:-word}, ${var:=word} etc) do the same,
+                        * but also treat null var as if it is unset.
+                        *
+                        * Word-splitting and single quote behavior:
+                        *
+                        * $ f() { for i; do echo "|$i|"; done; }
+                        *
+                        * $ x=; f ${x:?'x y' z}; echo $?
+                        * bash: x: x y z       # neither f nor "echo $?" executes
+                        * (if interactive, bash does not exit, but merely aborts to prompt. $? is set to 1)
+                        * $ x=; f "${x:?'x y' z}"
+                        * bash: x: x y z       # dash prints: dash: x: 'x y' z
+                        *
+                        * $ x=; f ${x:='x y' z}
+                        * |x|
+                        * |y|
+                        * |z|
+                        * $ x=; f "${x:='x y' z}"
+                        * |'x y' z|
+                        *
+                        * $ x=x; f ${x:+'x y' z}
+                        * |x y|
+                        * |z|
+                        * $ x=x; f "${x:+'x y' z}"
+                        * |'x y' z|
+                        *
+                        * $ x=; f ${x:-'x y' z}
+                        * |x y|
+                        * |z|
+                        * $ x=; f "${x:-'x y' z}"
+                        * |'x y' z|
+                        */
+                       int use_word = (!val || ((exp_save == ':') && !val[0]));
+                       if (exp_op == '+')
+                               use_word = !use_word;
+                       debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
+                                       (exp_save == ':') ? "true" : "false", use_word);
+                       if (use_word) {
+                               if (exp_op == '+' || exp_op == '-') {
+                                       /* ${var+word} - use alternative value */
+                                       /* ${var-word} - use default value */
+                                       n = encode_then_append_var_plusminus(output, n, exp_word,
+                                                       /*dquoted:*/ (arg0 & 0x80)
+                                       );
+                                       val = NULL;
+                               } else {
+                                       /* ${var?word} - indicate error if unset */
+                                       /* ${var=word} - assign and use default value */
+                                       to_be_freed = encode_then_expand_vararg(exp_word,
+                                                       /*handle_squotes:*/ !(arg0 & 0x80),
+                                                       /*unbackslash:*/ 0
+                                       );
+                                       if (to_be_freed)
+                                               exp_word = to_be_freed;
+                                       if (exp_op == '?') {
+                                               /* mimic bash message */
+                                               msg_and_die_if_script("%s: %s",
+                                                       var,
+                                                       exp_word[0]
+                                                       ? exp_word
+                                                       : "parameter null or not set"
+                                                       /* ash has more specific messages, a-la: */
+                                                       /*: (exp_save == ':' ? "parameter null or not set" : "parameter not set")*/
+                                               );
+//TODO: how interactive bash aborts expansion mid-command?
+//It aborts the entire line, returns to prompt:
+// $ f() { for i; do echo "|$i|"; done; }; x=; f "${x:?'x y' z}"; echo YO
+// bash: x: x y z
+// $
+// ("echo YO" is not executed, neither the f function call)
+                                       } else {
+                                               val = exp_word;
+                                       }
+                                       if (exp_op == '=') {
+                                               /* ${var=[word]} or ${var:=[word]} */
+                                               if (isdigit(var[0]) || var[0] == '#') {
+                                                       /* mimic bash message */
+                                                       msg_and_die_if_script("$%s: cannot assign in this way", var);
+                                                       val = NULL;
+                                               } else {
+                                                       char *new_var = xasprintf("%s=%s", var, val);
+                                                       set_local_var(new_var, /*flag:*/ 0);
+                                               }
+                                       }
+                               }
+                       }
+               } /* one of "-=+?" */
+
+               *exp_saveptr = exp_save;
+       } /* if (exp_op) */
+
+       arg[0] = arg0;
+       *pp = p;
+
+       n = append_str_maybe_ifs_split(output, n, first_ch, val);
+
+       free(to_be_freed);
+       return n;
+}
+
+/* Expand all variable references in given string, adding words to list[]
+ * at n, n+1,... positions. Return updated n (so that list[n] is next one
+ * to be filled). This routine is extremely tricky: has to deal with
+ * variables/parameters with whitespace, $* and $@, and constructs like
+ * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
+static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
+{
+       /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
+        * expansion of right-hand side of assignment == 1-element expand.
+        */
+       char cant_be_null = 0; /* only bit 0x80 matters */
+       char *p;
+
+       debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
+                       !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
+       debug_print_list("expand_vars_to_list[0]", output, n);
+
+       while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
+               char first_ch;
+#if ENABLE_FEATURE_SH_MATH
+               char arith_buf[sizeof(arith_t)*3 + 2];
+#endif
+
+               if (output->ended_in_ifs) {
+                       o_addchr(output, '\0');
+                       n = o_save_ptr(output, n);
+                       output->ended_in_ifs = 0;
+               }
+
+               o_addblock(output, arg, p - arg);
+               debug_print_list("expand_vars_to_list[1]", output, n);
+               arg = ++p;
+               p = strchr(p, SPECIAL_VAR_SYMBOL);
+
+               /* Fetch special var name (if it is indeed one of them)
+                * and quote bit, force the bit on if singleword expansion -
+                * important for not getting v=$@ expand to many words. */
+               first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
+
+               /* Is this variable quoted and thus expansion can't be null?
+                * "$@" is special. Even if quoted, it can still
+                * expand to nothing (not even an empty string),
+                * thus it is excluded. */
+               if ((first_ch & 0x7f) != '@')
+                       cant_be_null |= first_ch;
+
+               switch (first_ch & 0x7f) {
+               /* Highest bit in first_ch indicates that var is double-quoted */
+               case '*':
+               case '@': {
+                       int i;
+                       if (!G.global_argv[1])
+                               break;
+                       i = 1;
+                       cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
+                       if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
+                               while (G.global_argv[i]) {
+                                       n = expand_on_ifs(output, n, G.global_argv[i]);
+                                       debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
+                                       if (G.global_argv[i++][0] && G.global_argv[i]) {
+                                               /* this argv[] is not empty and not last:
+                                                * put terminating NUL, start new word */
+                                               o_addchr(output, '\0');
+                                               debug_print_list("expand_vars_to_list[2]", output, n);
+                                               n = o_save_ptr(output, n);
+                                               debug_print_list("expand_vars_to_list[3]", output, n);
+                                       }
+                               }
+                       } else
+                       /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
+                        * and in this case should treat it like '$*' - see 'else...' below */
+                       if (first_ch == (char)('@'|0x80)  /* quoted $@ */
+                        && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
+                       ) {
+                               while (1) {
+                                       o_addQstr(output, G.global_argv[i]);
+                                       if (++i >= G.global_argc)
+                                               break;
+                                       o_addchr(output, '\0');
+                                       debug_print_list("expand_vars_to_list[4]", output, n);
+                                       n = o_save_ptr(output, n);
+                               }
+                       } else { /* quoted $* (or v="$@" case): add as one word */
+                               while (1) {
+                                       o_addQstr(output, G.global_argv[i]);
+                                       if (!G.global_argv[++i])
+                                               break;
+                                       if (G.ifs[0])
+                                               o_addchr(output, G.ifs[0]);
+                               }
+                               output->has_quoted_part = 1;
+                       }
+                       break;
+               }
+               case SPECIAL_VAR_SYMBOL: {
+                       /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
+                       /* "Empty variable", used to make "" etc to not disappear */
+                       output->has_quoted_part = 1;
+                       cant_be_null = 0x80;
+                       arg++;
+                       break;
+               }
+               case SPECIAL_VAR_QUOTED_SVS:
+                       /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_QUOTED_SVS><SPECIAL_VAR_SYMBOL> */
+                       /* "^C variable", represents literal ^C char (possible in scripts) */
+                       o_addchr(output, SPECIAL_VAR_SYMBOL);
+                       arg++;
+                       break;
+#if ENABLE_HUSH_TICK
+               case '`': {
+                       /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
+                       o_string subst_result = NULL_O_STRING;
+
+                       *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
+                       arg++;
+                       /* Can't just stuff it into output o_string,
+                        * expanded result may need to be globbed
+                        * and $IFS-split */
+                       debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
+                       G.last_exitcode = process_command_subs(&subst_result, arg);
+                       G.expand_exitcode = G.last_exitcode;
+                       debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
+                       n = append_str_maybe_ifs_split(output, n, first_ch, subst_result.data);
+                       o_free(&subst_result);
+                       break;
+               }
+#endif
+#if ENABLE_FEATURE_SH_MATH
+               case '+': {
+                       /* <SPECIAL_VAR_SYMBOL>+arith<SPECIAL_VAR_SYMBOL> */
+                       arith_t res;
+
+                       arg++; /* skip '+' */
+                       *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
+                       debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
+                       res = expand_and_evaluate_arith(arg, NULL);
+                       debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
+                       sprintf(arith_buf, ARITH_FMT, res);
+                       if (res < 0
+                        && first_ch == (char)('+'|0x80)
+                       /* && (output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS) */
+                       ) {
+                               /* Quoted negative ariths, like filename[0"$((-9))"],
+                                * should not be interpreted as glob ranges.
+                                * Convert leading '-' to '\-':
+                                */
+                               o_grow_by(output, 1);
+                               output->data[output->length++] = '\\';
+                       }
+                       o_addstr(output, arith_buf);
+                       break;
+               }
+#endif
+               default:
+                       /* <SPECIAL_VAR_SYMBOL>varname[ops]<SPECIAL_VAR_SYMBOL> */
+                       n = expand_one_var(output, n, first_ch, arg, &p);
+                       break;
+               } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
+
+               /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
+                * Do the check to avoid writing to a const string. */
+               if (*p != SPECIAL_VAR_SYMBOL)
+                       *p = SPECIAL_VAR_SYMBOL;
+               arg = ++p;
+       } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
+
+       if (*arg) {
+               /* handle trailing string */
+               if (output->ended_in_ifs) {
+                       o_addchr(output, '\0');
+                       n = o_save_ptr(output, n);
+               }
+               debug_print_list("expand_vars_to_list[a]", output, n);
+               /* this part is literal, and it was already pre-quoted
+                * if needed (much earlier), do not use o_addQstr here!
+                */
+               o_addstr(output, arg);
+               debug_print_list("expand_vars_to_list[b]", output, n);
+       } else
+       if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
+        && !(cant_be_null & 0x80)   /* and all vars were not quoted */
+        && !output->has_quoted_part
+       ) {
+               n--;
+               /* allow to reuse list[n] later without re-growth */
+               output->has_empty_slot = 1;
+       }
+
+       return n;
+}
+
+static char **expand_variables(char **argv, unsigned expflags)
+{
+       int n;
+       char **list;
+       o_string output = NULL_O_STRING;
+
+       output.o_expflags = expflags;
+
+       n = 0;
+       for (;;) {
+               /* go to next list[n] */
+               output.ended_in_ifs = 0;
+               n = o_save_ptr(&output, n);
+
+               if (!*argv)
+                       break;
+
+               /* expand argv[i] */
+               n = expand_vars_to_list(&output, n, *argv++);
+               /* if (!output->has_empty_slot) -- need this?? */
+                       o_addchr(&output, '\0');
+       }
+       debug_print_list("expand_variables", &output, n);
+
+       /* output.data (malloced in one block) gets returned in "list" */
+       list = o_finalize_list(&output, n);
+       debug_print_strings("expand_variables[1]", list);
+       return list;
+}
+
+static char **expand_strvec_to_strvec(char **argv)
+{
+       return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
+}
+
+#if defined(CMD_SINGLEWORD_NOGLOB) || defined(CMD_TEST2_SINGLEWORD_NOGLOB)
+static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
+{
+       return expand_variables(argv, EXP_FLAG_SINGLEWORD);
+}
+#endif
+
+/* Used for expansion of right hand of assignments,
+ * $((...)), heredocs, variable expansion parts.
+ *
+ * NB: should NOT do globbing!
+ * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
+ */
+static char *expand_string_to_string(const char *str, int EXP_flags, int do_unbackslash)
+{
+#if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
+       const int do_unbackslash = 1;
+       const int EXP_flags = EXP_FLAG_ESC_GLOB_CHARS;
+#endif
+       char *argv[2], **list;
+
+       debug_printf_expand("string_to_string<='%s'\n", str);
+       /* This is generally an optimization, but it also
+        * handles "", which otherwise trips over !list[0] check below.
+        * (is this ever happens that we actually get str="" here?)
+        */
+       if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
+               //TODO: Can use on strings with \ too, just unbackslash() them?
+               debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
+               return xstrdup(str);
+       }
+
+       argv[0] = (char*)str;
+       argv[1] = NULL;
+       list = expand_variables(argv, EXP_flags | EXP_FLAG_SINGLEWORD);
+       if (!list[0]) {
+               /* Example where it happens:
+                * x=; echo ${x:-"$@"}
+                */
+               ((char*)list)[0] = '\0';
+       } else {
+               if (HUSH_DEBUG)
+                       if (list[1])
+                               bb_simple_error_msg_and_die("BUG in varexp2");
+               /* actually, just move string 2*sizeof(char*) bytes back */
+               overlapping_strcpy((char*)list, list[0]);
+               if (do_unbackslash)
+                       unbackslash((char*)list);
+       }
+       debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
+       return (char*)list;
+}
+
+#if 0
+static char* expand_strvec_to_string(char **argv)
+{
+       char **list;
+
+       list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
+       /* Convert all NULs to spaces */
+       if (list[0]) {
+               int n = 1;
+               while (list[n]) {
+                       if (HUSH_DEBUG)
+                               if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
+                                       bb_error_msg_and_die("BUG in varexp3");
+                       /* bash uses ' ' regardless of $IFS contents */
+                       list[n][-1] = ' ';
+                       n++;
+               }
+       }
+       overlapping_strcpy((char*)list, list[0] ? list[0] : "");
+       debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
+       return (char*)list;
+}
+#endif
+
+static char **expand_assignments(char **argv, int count)
+{
+       int i;
+       char **p;
+
+       G.expanded_assignments = p = NULL;
+       /* Expand assignments into one string each */
+       for (i = 0; i < count; i++) {
+               p = add_string_to_strings(p,
+                       expand_string_to_string(argv[i],
+                               EXP_FLAG_ESC_GLOB_CHARS,
+                               /*unbackslash:*/ 1
+                       )
+               );
+               G.expanded_assignments = p;
+       }
+       G.expanded_assignments = NULL;
+       return p;
+}
+
+
+static void switch_off_special_sigs(unsigned mask)
+{
+       unsigned sig = 0;
+       while ((mask >>= 1) != 0) {
+               sig++;
+               if (!(mask & 1))
+                       continue;
+#if ENABLE_HUSH_TRAP
+               if (G_traps) {
+                       if (G_traps[sig] && !G_traps[sig][0])
+                               /* trap is '', has to remain SIG_IGN */
+                               continue;
+                       free(G_traps[sig]);
+                       G_traps[sig] = NULL;
+               }
+#endif
+               /* We are here only if no trap or trap was not '' */
+               install_sighandler(sig, SIG_DFL);
+       }
+}
+
+#if BB_MMU
+/* never called */
+void re_execute_shell(char ***to_free, const char *s,
+               char *g_argv0, char **g_argv,
+               char **builtin_argv) NORETURN;
+
+static void reset_traps_to_defaults(void)
+{
+       /* This function is always called in a child shell
+        * after fork (not vfork, NOMMU doesn't use this function).
+        */
+       IF_HUSH_TRAP(unsigned sig;)
+       unsigned mask;
+
+       /* Child shells are not interactive.
+        * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
+        * Testcase: (while :; do :; done) + ^Z should background.
+        * Same goes for SIGTERM, SIGHUP, SIGINT.
+        */
+       mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
+       if (!G_traps && !mask)
+               return; /* already no traps and no special sigs */
+
+       /* Switch off special sigs */
+       switch_off_special_sigs(mask);
+# if ENABLE_HUSH_JOB
+       G_fatal_sig_mask = 0;
+# endif
+       G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
+       /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
+        * remain set in G.special_sig_mask */
+
+# if ENABLE_HUSH_TRAP
+       if (!G_traps)
+               return;
+
+       /* Reset all sigs to default except ones with empty traps */
+       for (sig = 0; sig < NSIG; sig++) {
+               if (!G_traps[sig])
+                       continue; /* no trap: nothing to do */
+               if (!G_traps[sig][0])
+                       continue; /* empty trap: has to remain SIG_IGN */
+               /* sig has non-empty trap, reset it: */
+               free(G_traps[sig]);
+               G_traps[sig] = NULL;
+               /* There is no signal for trap 0 (EXIT) */
+               if (sig == 0)
+                       continue;
+               install_sighandler(sig, pick_sighandler(sig));
+       }
+# endif
+}
+
+#else /* !BB_MMU */
+
+static void re_execute_shell(char ***to_free, const char *s,
+               char *g_argv0, char **g_argv,
+               char **builtin_argv) NORETURN;
+static void re_execute_shell(char ***to_free, const char *s,
+               char *g_argv0, char **g_argv,
+               char **builtin_argv)
+{
+# define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
+       /* delims + 2 * (number of bytes in printed hex numbers) */
+       char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
+       char *heredoc_argv[4];
+       struct variable *cur;
+# if ENABLE_HUSH_FUNCTIONS
+       struct function *funcp;
+# endif
+       char **argv, **pp;
+       unsigned cnt;
+       unsigned long long empty_trap_mask;
+
+       if (!g_argv0) { /* heredoc */
+               argv = heredoc_argv;
+               argv[0] = (char *) G.argv0_for_re_execing;
+               argv[1] = (char *) "-<";
+               argv[2] = (char *) s;
+               argv[3] = NULL;
+               pp = &argv[3]; /* used as pointer to empty environment */
+               goto do_exec;
+       }
+
+       cnt = 0;
+       pp = builtin_argv;
+       if (pp) while (*pp++)
+               cnt++;
+
+       empty_trap_mask = 0;
+       if (G_traps) {
+               int sig;
+               for (sig = 1; sig < NSIG; sig++) {
+                       if (G_traps[sig] && !G_traps[sig][0])
+                               empty_trap_mask |= 1LL << sig;
+               }
+       }
+
+       sprintf(param_buf, NOMMU_HACK_FMT
+                       , (unsigned) G.root_pid
+                       , (unsigned) G.root_ppid
+                       , (unsigned) G.last_bg_pid
+                       , (unsigned) G.last_exitcode
+                       , cnt
+                       , empty_trap_mask
+                       IF_HUSH_LOOPS(, G.depth_of_loop)
+                       );
+# undef NOMMU_HACK_FMT
+       /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
+        * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
+        */
+       cnt += 6;
+       for (cur = G.top_var; cur; cur = cur->next) {
+               if (!cur->flg_export || cur->flg_read_only)
+                       cnt += 2;
+       }
+# if ENABLE_HUSH_FUNCTIONS
+       for (funcp = G.top_func; funcp; funcp = funcp->next)
+               cnt += 3;
+# endif
+       pp = g_argv;
+       while (*pp++)
+               cnt++;
+       *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
+       *pp++ = (char *) G.argv0_for_re_execing;
+       *pp++ = param_buf;
+       for (cur = G.top_var; cur; cur = cur->next) {
+               if (strcmp(cur->varstr, hush_version_str) == 0)
+                       continue;
+               if (cur->flg_read_only) {
+                       *pp++ = (char *) "-R";
+                       *pp++ = cur->varstr;
+               } else if (!cur->flg_export) {
+                       *pp++ = (char *) "-V";
+                       *pp++ = cur->varstr;
+               }
+       }
+# if ENABLE_HUSH_FUNCTIONS
+       for (funcp = G.top_func; funcp; funcp = funcp->next) {
+               *pp++ = (char *) "-F";
+               *pp++ = funcp->name;
+               *pp++ = funcp->body_as_string;
+       }
+# endif
+       /* We can pass activated traps here. Say, -Tnn:trap_string
+        *
+        * However, POSIX says that subshells reset signals with traps
+        * to SIG_DFL.
+        * I tested bash-3.2 and it not only does that with true subshells
+        * of the form ( list ), but with any forked children shells.
+        * I set trap "echo W" WINCH; and then tried:
+        *
+        * { echo 1; sleep 20; echo 2; } &
+        * while true; do echo 1; sleep 20; echo 2; break; done &
+        * true | { echo 1; sleep 20; echo 2; } | cat
+        *
+        * In all these cases sending SIGWINCH to the child shell
+        * did not run the trap. If I add trap "echo V" WINCH;
+        * _inside_ group (just before echo 1), it works.
+        *
+        * I conclude it means we don't need to pass active traps here.
+        */
+       *pp++ = (char *) "-c";
+       *pp++ = (char *) s;
+       if (builtin_argv) {
+               while (*++builtin_argv)
+                       *pp++ = *builtin_argv;
+               *pp++ = (char *) "";
+       }
+       *pp++ = g_argv0;
+       while (*g_argv)
+               *pp++ = *g_argv++;
+       /* *pp = NULL; - is already there */
+       pp = environ;
+
+ do_exec:
+       debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
+       /* Don't propagate SIG_IGN to the child */
+       if (SPECIAL_JOBSTOP_SIGS != 0)
+               switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
+       execve(bb_busybox_exec_path, argv, pp);
+       /* Fallback. Useful for init=/bin/hush usage etc */
+       if (argv[0][0] == '/')
+               execve(argv[0], argv, pp);
+       xfunc_error_retval = 127;
+       bb_simple_error_msg_and_die("can't re-execute the shell");
+}
+#endif  /* !BB_MMU */
+
+
+static int run_and_free_list(struct pipe *pi);
+
+/* Executing from string: eval, sh -c '...'
+ *          or from file: /etc/profile, . file, sh <script>, sh (intereactive)
+ * end_trigger controls how often we stop parsing
+ * NUL: parse all, execute, return
+ * ';': parse till ';' or newline, execute, repeat till EOF
+ */
+static void parse_and_run_stream(struct in_str *inp, int end_trigger)
+{
+       /* Why we need empty flag?
+        * An obscure corner case "false; ``; echo $?":
+        * empty command in `` should still set $? to 0.
+        * But we can't just set $? to 0 at the start,
+        * this breaks "false; echo `echo $?`" case.
+        */
+       bool empty = 1;
+       while (1) {
+               struct pipe *pipe_list;
+
+#if ENABLE_HUSH_INTERACTIVE
+               if (end_trigger == ';') {
+                       G.promptmode = 0; /* PS1 */
+                       debug_printf_prompt("%s promptmode=%d\n", __func__, G.promptmode);
+               }
+#endif
+               pipe_list = parse_stream(NULL, NULL, inp, end_trigger);
+               if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
+                       /* If we are in "big" script
+                        * (not in `cmd` or something similar)...
+                        */
+                       if (pipe_list == ERR_PTR && end_trigger == ';') {
+                               /* Discard cached input (rest of line) */
+                               int ch = inp->last_char;
+                               while (ch != EOF && ch != '\n') {
+                                       //bb_error_msg("Discarded:'%c'", ch);
+                                       ch = i_getch(inp);
+                               }
+                               /* Force prompt */
+                               inp->p = NULL;
+                               /* This stream isn't empty */
+                               empty = 0;
+                               continue;
+                       }
+                       if (!pipe_list && empty)
+                               G.last_exitcode = 0;
+                       break;
+               }
+               debug_print_tree(pipe_list, 0);
+               debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
+               run_and_free_list(pipe_list);
+               empty = 0;
+               if (G_flag_return_in_progress == 1)
+                       break;
+       }
+}
+
+static void parse_and_run_string(const char *s)
+{
+       struct in_str input;
+       //IF_HUSH_LINENO_VAR(unsigned sv = G.parse_lineno;)
+
+       setup_string_in_str(&input, s);
+       parse_and_run_stream(&input, '\0');
+       //IF_HUSH_LINENO_VAR(G.parse_lineno = sv;)
+}
+
+static void parse_and_run_file(HFILE *fp)
+{
+       struct in_str input;
+       IF_HUSH_LINENO_VAR(unsigned sv = G.parse_lineno;)
+
+       IF_HUSH_LINENO_VAR(G.parse_lineno = 1;)
+       setup_file_in_str(&input, fp);
+       parse_and_run_stream(&input, ';');
+       IF_HUSH_LINENO_VAR(G.parse_lineno = sv;)
+}
+
+#if ENABLE_HUSH_TICK
+static int generate_stream_from_string(const char *s, pid_t *pid_p)
+{
+       pid_t pid;
+       int channel[2];
+# if !BB_MMU
+       char **to_free = NULL;
+# endif
+
+       xpipe(channel);
+       pid = BB_MMU ? xfork() : xvfork();
+       if (pid == 0) { /* child */
+               disable_restore_tty_pgrp_on_exit();
+               /* Process substitution is not considered to be usual
+                * 'command execution'.
+                * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
+                */
+               bb_signals(0
+                       + (1 << SIGTSTP)
+                       + (1 << SIGTTIN)
+                       + (1 << SIGTTOU)
+                       , SIG_IGN);
+               close(channel[0]); /* NB: close _first_, then move fd! */
+               xmove_fd(channel[1], 1);
+# if ENABLE_HUSH_TRAP
+               /* Awful hack for `trap` or $(trap).
+                *
+                * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
+                * contains an example where "trap" is executed in a subshell:
+                *
+                * save_traps=$(trap)
+                * ...
+                * eval "$save_traps"
+                *
+                * Standard does not say that "trap" in subshell shall print
+                * parent shell's traps. It only says that its output
+                * must have suitable form, but then, in the above example
+                * (which is not supposed to be normative), it implies that.
+                *
+                * bash (and probably other shell) does implement it
+                * (traps are reset to defaults, but "trap" still shows them),
+                * but as a result, "trap" logic is hopelessly messed up:
+                *
+                * # trap
+                * trap -- 'echo Ho' SIGWINCH  <--- we have a handler
+                * # (trap)        <--- trap is in subshell - no output (correct, traps are reset)
+                * # true | trap   <--- trap is in subshell - no output (ditto)
+                * # echo `true | trap`    <--- in subshell - output (but traps are reset!)
+                * trap -- 'echo Ho' SIGWINCH
+                * # echo `(trap)`         <--- in subshell in subshell - output
+                * trap -- 'echo Ho' SIGWINCH
+                * # echo `true | (trap)`  <--- in subshell in subshell in subshell - output!
+                * trap -- 'echo Ho' SIGWINCH
+                *
+                * The rules when to forget and when to not forget traps
+                * get really complex and nonsensical.
+                *
+                * Our solution: ONLY bare $(trap) or `trap` is special.
+                */
+               s = skip_whitespace(s);
+               if (is_prefixed_with(s, "trap")
+                && skip_whitespace(s + 4)[0] == '\0'
+               ) {
+                       static const char *const argv[] = { NULL, NULL };
+                       builtin_trap((char**)argv);
+                       fflush_all(); /* important */
+                       _exit(0);
+               }
+# endif
+# if BB_MMU
+               /* Prevent it from trying to handle ctrl-z etc */
+               IF_HUSH_JOB(G.run_list_level = 1;)
+               CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
+               reset_traps_to_defaults();
+               IF_HUSH_MODE_X(G.x_mode_depth++;)
+               //bb_error_msg("%s: ++x_mode_depth=%d", __func__, G.x_mode_depth);
+               parse_and_run_string(s);
+               _exit(G.last_exitcode);
+# else
+       /* We re-execute after vfork on NOMMU. This makes this script safe:
+        * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
+        * huge=`cat BIG` # was blocking here forever
+        * echo OK
+        */
+               re_execute_shell(&to_free,
+                               s,
+                               G.global_argv[0],
+                               G.global_argv + 1,
+                               NULL);
+# endif
+       }
+
+       /* parent */
+       *pid_p = pid;
+# if ENABLE_HUSH_FAST
+       G.count_SIGCHLD++;
+//bb_error_msg("[%d] fork in generate_stream_from_string:"
+//             " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
+//             getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
+# endif
+       enable_restore_tty_pgrp_on_exit();
+# if !BB_MMU
+       free(to_free);
+# endif
+       close(channel[1]);
+       return channel[0];
+}
+
+/* Return code is exit status of the process that is run. */
+static int process_command_subs(o_string *dest, const char *s)
+{
+       FILE *fp;
+       pid_t pid;
+       int status, ch, eol_cnt;
+
+       fp = xfdopen_for_read(generate_stream_from_string(s, &pid));
+
+       /* Now send results of command back into original context */
+       eol_cnt = 0;
+       while ((ch = getc(fp)) != EOF) {
+               if (ch == '\0')
+                       continue;
+               if (ch == '\n') {
+                       eol_cnt++;
+                       continue;
+               }
+               while (eol_cnt) {
+                       o_addchr(dest, '\n');
+                       eol_cnt--;
+               }
+               o_addQchr(dest, ch);
+       }
+
+       debug_printf("done reading from `cmd` pipe, closing it\n");
+       fclose(fp);
+       /* We need to extract exitcode. Test case
+        * "true; echo `sleep 1; false` $?"
+        * should print 1 */
+       safe_waitpid(pid, &status, 0);
+       debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
+       return WEXITSTATUS(status);
+}
+#endif /* ENABLE_HUSH_TICK */
+
+
+static void setup_heredoc(struct redir_struct *redir)
+{
+       struct fd_pair pair;
+       pid_t pid;
+       int len, written;
+       /* the _body_ of heredoc (misleading field name) */
+       const char *heredoc = redir->rd_filename;
+       char *expanded;
+#if !BB_MMU
+       char **to_free;
+#endif
+
+       expanded = NULL;
+       if (!(redir->rd_dup & HEREDOC_QUOTED)) {
+               expanded = encode_then_expand_string(heredoc);
+               if (expanded)
+                       heredoc = expanded;
+       }
+       len = strlen(heredoc);
+
+       close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
+       xpiped_pair(pair);
+       xmove_fd(pair.rd, redir->rd_fd);
+
+       /* Try writing without forking. Newer kernels have
+        * dynamically growing pipes. Must use non-blocking write! */
+       ndelay_on(pair.wr);
+       while (1) {
+               written = write(pair.wr, heredoc, len);
+               if (written <= 0)
+                       break;
+               len -= written;
+               if (len == 0) {
+                       close(pair.wr);
+                       free(expanded);
+                       return;
+               }
+               heredoc += written;
+       }
+       ndelay_off(pair.wr);
+
+       /* Okay, pipe buffer was not big enough */
+       /* Note: we must not create a stray child (bastard? :)
+        * for the unsuspecting parent process. Child creates a grandchild
+        * and exits before parent execs the process which consumes heredoc
+        * (that exec happens after we return from this function) */
+#if !BB_MMU
+       to_free = NULL;
+#endif
+       pid = xvfork();
+       if (pid == 0) {
+               /* child */
+               disable_restore_tty_pgrp_on_exit();
+               pid = BB_MMU ? xfork() : xvfork();
+               if (pid != 0)
+                       _exit(0);
+               /* grandchild */
+               close(redir->rd_fd); /* read side of the pipe */
+#if BB_MMU
+               full_write(pair.wr, heredoc, len); /* may loop or block */
+               _exit(0);
+#else
+               /* Delegate blocking writes to another process */
+               xmove_fd(pair.wr, STDOUT_FILENO);
+               re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
+#endif
+       }
+       /* parent */
+#if ENABLE_HUSH_FAST
+       G.count_SIGCHLD++;
+//bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
+#endif
+       enable_restore_tty_pgrp_on_exit();
+#if !BB_MMU
+       free(to_free);
+#endif
+       close(pair.wr);
+       free(expanded);
+       wait(NULL); /* wait till child has died */
+}
+
+struct squirrel {
+       int orig_fd;
+       int moved_to;
+       /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
+       /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
+};
+
+static struct squirrel *append_squirrel(struct squirrel *sq, int i, int orig, int moved)
+{
+       sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
+       sq[i].orig_fd = orig;
+       sq[i].moved_to = moved;
+       sq[i+1].orig_fd = -1; /* end marker */
+       return sq;
+}
+
+static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
+{
+       int moved_to;
+       int i;
+
+       i = 0;
+       if (sq) for (; sq[i].orig_fd >= 0; i++) {
+               /* If we collide with an already moved fd... */
+               if (fd == sq[i].moved_to) {
+                       sq[i].moved_to = dup_CLOEXEC(sq[i].moved_to, avoid_fd);
+                       debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
+                       if (sq[i].moved_to < 0) /* what? */
+                               xfunc_die();
+                       return sq;
+               }
+               if (fd == sq[i].orig_fd) {
+                       /* Example: echo Hello >/dev/null 1>&2 */
+                       debug_printf_redir("redirect_fd %d: already moved\n", fd);
+                       return sq;
+               }
+       }
+
+       /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
+       moved_to = dup_CLOEXEC(fd, avoid_fd);
+       debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to);
+       if (moved_to < 0 && errno != EBADF)
+               xfunc_die();
+       return append_squirrel(sq, i, fd, moved_to);
+}
+
+static struct squirrel *add_squirrel_closed(struct squirrel *sq, int fd)
+{
+       int i;
+
+       i = 0;
+       if (sq) for (; sq[i].orig_fd >= 0; i++) {
+               /* If we collide with an already moved fd... */
+               if (fd == sq[i].orig_fd) {
+                       /* Examples:
+                        * "echo 3>FILE 3>&- 3>FILE"
+                        * "echo 3>&- 3>FILE"
+                        * No need for last redirect to insert
+                        * another "need to close 3" indicator.
+                        */
+                       debug_printf_redir("redirect_fd %d: already moved or closed\n", fd);
+                       return sq;
+               }
+       }
+
+       debug_printf_redir("redirect_fd %d: previous fd was closed\n", fd);
+       return append_squirrel(sq, i, fd, -1);
+}
+
+/* fd: redirect wants this fd to be used (e.g. 3>file).
+ * Move all conflicting internally used fds,
+ * and remember them so that we can restore them later.
+ */
+static int save_fd_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
+{
+       if (avoid_fd < 9) /* the important case here is that it can be -1 */
+               avoid_fd = 9;
+
+#if ENABLE_HUSH_INTERACTIVE
+       if (fd != 0 /* don't trigger for G_interactive_fd == 0 (that's "not interactive" flag) */
+        && fd == G_interactive_fd
+       ) {
+               /* Testcase: "ls -l /proc/$$/fd 255>&-" should work */
+               G_interactive_fd = xdup_CLOEXEC_and_close(G_interactive_fd, avoid_fd);
+               debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G_interactive_fd);
+               return 1; /* "we closed fd" */
+       }
+#endif
+       /* Are we called from setup_redirects(squirrel==NULL)
+        * in redirect in a [v]forked child?
+        */
+       if (sqp == NULL) {
+               /* No need to move script fds.
+                * For NOMMU case, it's actively wrong: we'd change ->fd
+                * fields in memory for the parent, but parent's fds
+                * aren't moved, it would use wrong fd!
+                * Reproducer: "cmd 3>FILE" in script.
+                * If we would call move_HFILEs_on_redirect(), child would:
+                *  fcntl64(3, F_DUPFD_CLOEXEC, 10)   = 10
+                *  close(3)                          = 0
+                * and change ->fd to 10 if fd#3 is a script fd. WRONG.
+                */
+               //bb_error_msg("sqp == NULL: [v]forked child");
+               return 0;
+       }
+
+       /* If this one of script's fds? */
+       if (move_HFILEs_on_redirect(fd, avoid_fd))
+               return 1; /* yes. "we closed fd" (actually moved it) */
+
+       /* Are we called for "exec 3>FILE"? Came through
+        * redirect_and_varexp_helper(squirrel=ERR_PTR) -> setup_redirects(ERR_PTR)
+        * This case used to fail for this script:
+        *  exec 3>FILE
+        *  echo Ok
+        *  ...100000 more lines...
+        *  echo Ok
+        * as follows:
+        *  read(3, "exec 3>FILE\necho Ok\necho Ok"..., 1024) = 1024
+        *  open("FILE", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE, 0666) = 4
+        *  dup2(4, 3)                        = 3
+        *  ^^^^^^^^ oops, we lost fd#3 opened to our script!
+        *  close(4)                          = 0
+        *  write(1, "Ok\n", 3)               = 3
+        *  ...                               = 3
+        *  write(1, "Ok\n", 3)               = 3
+        *  read(3, 0x94fbc08, 1024)          = -1 EBADF (Bad file descriptor)
+        *  ^^^^^^^^ oops, wrong fd!!!
+        * With this case separate from sqp == NULL and *after* move_HFILEs,
+        * it now works:
+        */
+       if (sqp == ERR_PTR) {
+               /* Don't preserve redirected fds: exec is _meant_ to change these */
+               //bb_error_msg("sqp == ERR_PTR: exec >FILE");
+               return 0;
+       }
+
+       /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
+       *sqp = add_squirrel(*sqp, fd, avoid_fd);
+       return 0; /* "we did not close fd" */
+}
+
+static void restore_redirects(struct squirrel *sq)
+{
+       if (sq) {
+               int i;
+               for (i = 0; sq[i].orig_fd >= 0; i++) {
+                       if (sq[i].moved_to >= 0) {
+                               /* We simply die on error */
+                               debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
+                               xmove_fd(sq[i].moved_to, sq[i].orig_fd);
+                       } else {
+                               /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
+                               debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
+                               close(sq[i].orig_fd);
+                       }
+               }
+               free(sq);
+       }
+       if (G.HFILE_stdin
+        && G.HFILE_stdin->fd > STDIN_FILENO
+       /* we compare > STDIN, not == STDIN, since hfgetc()
+        * closes fd and sets ->fd to -1 if EOF is reached.
+        * Testcase: echo 'pwd' | hush
+        */
+       ) {
+               /* Testcase: interactive "read r <FILE; echo $r; read r; echo $r".
+                * Redirect moves ->fd to e.g. 10,
+                * and it is not restored above (we do not restore script fds
+                * after redirects, we just use new, "moved" fds).
+                * However for stdin, get_user_input() -> read_line_input(),
+                * and read builtin, depend on fd == STDIN_FILENO.
+                */
+               debug_printf_redir("restoring %d to stdin\n", G.HFILE_stdin->fd);
+               xmove_fd(G.HFILE_stdin->fd, STDIN_FILENO);
+               G.HFILE_stdin->fd = STDIN_FILENO;
+       }
+
+       /* If moved, G_interactive_fd stays on new fd, not restoring it */
+}
+
+#if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
+static void close_saved_fds_and_FILE_fds(void)
+{
+       if (G_interactive_fd)
+               close(G_interactive_fd);
+       close_all_HFILE_list();
+}
+#endif
+
+static int internally_opened_fd(int fd, struct squirrel *sq)
+{
+       int i;
+
+#if ENABLE_HUSH_INTERACTIVE
+       if (fd == G_interactive_fd)
+               return 1;
+#endif
+       /* If this one of script's fds? */
+       if (fd_in_HFILEs(fd))
+               return 1;
+
+       if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
+               if (fd == sq[i].moved_to)
+                       return 1;
+       }
+       return 0;
+}
+
+/* squirrel != NULL means we squirrel away copies of stdin, stdout,
+ * and stderr if they are redirected. */
+static int setup_redirects(struct command *prog, struct squirrel **sqp)
+{
+       struct redir_struct *redir;
+
+       for (redir = prog->redirects; redir; redir = redir->next) {
+               int newfd;
+               int closed;
+
+               if (redir->rd_type == REDIRECT_HEREDOC2) {
+                       /* "rd_fd<<HERE" case */
+                       save_fd_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
+                       /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
+                        * of the heredoc */
+                       debug_printf_redir("set heredoc '%s'\n",
+                                       redir->rd_filename);
+                       setup_heredoc(redir);
+                       continue;
+               }
+
+               if (redir->rd_dup == REDIRFD_TO_FILE) {
+                       /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
+                       char *p;
+                       int mode;
+
+                       if (redir->rd_filename == NULL) {
+                               /* Examples:
+                                * "cmd >" (no filename)
+                                * "cmd > <file" (2nd redirect starts too early)
+                                */
+                               syntax_error("invalid redirect");
+                               continue;
+                       }
+                       mode = redir_table[redir->rd_type].mode;
+                       p = expand_string_to_string(redir->rd_filename,
+                               EXP_FLAG_ESC_GLOB_CHARS, /*unbackslash:*/ 1);
+                       newfd = open_or_warn(p, mode);
+                       free(p);
+                       if (newfd < 0) {
+                               /* Error message from open_or_warn can be lost
+                                * if stderr has been redirected, but bash
+                                * and ash both lose it as well
+                                * (though zsh doesn't!)
+                                */
+                               return 1;
+                       }
+                       if (newfd == redir->rd_fd && sqp) {
+                               /* open() gave us precisely the fd we wanted.
+                                * This means that this fd was not busy
+                                * (not opened to anywhere).
+                                * Remember to close it on restore:
+                                */
+                               *sqp = add_squirrel_closed(*sqp, newfd);
+                               debug_printf_redir("redir to previously closed fd %d\n", newfd);
+                       }
+               } else {
+                       /* "rd_fd>&rd_dup" or "rd_fd>&-" case */
+                       newfd = redir->rd_dup;
+               }
+
+               if (newfd == redir->rd_fd)
+                       continue;
+
+               /* if "N>FILE": move newfd to redir->rd_fd */
+               /* if "N>&M": dup newfd to redir->rd_fd */
+               /* if "N>&-": close redir->rd_fd (newfd is REDIRFD_CLOSE) */
+
+               closed = save_fd_on_redirect(redir->rd_fd, /*avoid:*/ newfd, sqp);
+               if (newfd == REDIRFD_CLOSE) {
+                       /* "N>&-" means "close me" */
+                       if (!closed) {
+                               /* ^^^ optimization: saving may already
+                                * have closed it. If not... */
+                               close(redir->rd_fd);
+                       }
+                       /* Sometimes we do another close on restore, getting EBADF.
+                        * Consider "echo 3>FILE 3>&-"
+                        * first redirect remembers "need to close 3",
+                        * and second redirect closes 3! Restore code then closes 3 again.
+                        */
+               } else {
+                       /* if newfd is a script fd or saved fd, simulate EBADF */
+                       if (internally_opened_fd(newfd, sqp && sqp != ERR_PTR ? *sqp : NULL)) {
+                               //errno = EBADF;
+                               //bb_perror_msg_and_die("can't duplicate file descriptor");
+                               newfd = -1; /* same effect as code above */
+                       }
+                       xdup2(newfd, redir->rd_fd);
+                       if (redir->rd_dup == REDIRFD_TO_FILE)
+                               /* "rd_fd > FILE" */
+                               close(newfd);
+                       /* else: "rd_fd > rd_dup" */
+               }
+       }
+       return 0;
+}
+
+static char *find_in_path(const char *arg)
+{
+       char *ret = NULL;
+       const char *PATH = get_local_var_value("PATH");
+
+       if (!PATH)
+               return NULL;
+
+       while (1) {
+               const char *end = strchrnul(PATH, ':');
+               int sz = end - PATH; /* must be int! */
+
+               free(ret);
+               if (sz != 0) {
+                       ret = xasprintf("%.*s/%s", sz, PATH, arg);
+               } else {
+                       /* We have xxx::yyyy in $PATH,
+                        * it means "use current dir" */
+                       ret = xstrdup(arg);
+               }
+               if (access(ret, F_OK) == 0)
+                       break;
+
+               if (*end == '\0') {
+                       free(ret);
+                       return NULL;
+               }
+               PATH = end + 1;
+       }
+
+       return ret;
+}
+
+static const struct built_in_command *find_builtin_helper(const char *name,
+               const struct built_in_command *x,
+               const struct built_in_command *end)
+{
+       while (x != end) {
+               if (strcmp(name, x->b_cmd) != 0) {
+                       x++;
+                       continue;
+               }
+               debug_printf_exec("found builtin '%s'\n", name);
+               return x;
+       }
+       return NULL;
+}
+static const struct built_in_command *find_builtin1(const char *name)
+{
+       return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
+}
+static const struct built_in_command *find_builtin(const char *name)
+{
+       const struct built_in_command *x = find_builtin1(name);
+       if (x)
+               return x;
+       return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
+}
+
+#if ENABLE_HUSH_JOB && EDITING_HAS_get_exe_name
+static const char * FAST_FUNC get_builtin_name(int i)
+{
+       if (/*i >= 0 && */ i < ARRAY_SIZE(bltins1)) {
+               return bltins1[i].b_cmd;
+       }
+       i -= ARRAY_SIZE(bltins1);
+       if (i < ARRAY_SIZE(bltins2)) {
+               return bltins2[i].b_cmd;
+       }
+       return NULL;
+}
+#endif
+
+static void remove_nested_vars(void)
+{
+       struct variable *cur;
+       struct variable **cur_pp;
+
+       cur_pp = &G.top_var;
+       while ((cur = *cur_pp) != NULL) {
+               if (cur->var_nest_level <= G.var_nest_level) {
+                       cur_pp = &cur->next;
+                       continue;
+               }
+               /* Unexport */
+               if (cur->flg_export) {
+                       debug_printf_env("unexporting nested '%s'/%u\n", cur->varstr, cur->var_nest_level);
+                       bb_unsetenv(cur->varstr);
+               }
+               /* Remove from global list */
+               *cur_pp = cur->next;
+               /* Free */
+               if (!cur->max_len) {
+                       debug_printf_env("freeing nested '%s'/%u\n", cur->varstr, cur->var_nest_level);
+                       free(cur->varstr);
+               }
+               free(cur);
+       }
+}
+
+static void enter_var_nest_level(void)
+{
+       G.var_nest_level++;
+       debug_printf_env("var_nest_level++ %u\n", G.var_nest_level);
+
+       /* Try: f() { echo -n .; f; }; f
+        * struct variable::var_nest_level is uint16_t,
+        * thus limiting recursion to < 2^16.
+        * In any case, with 8 Mbyte stack SEGV happens
+        * not too long after 2^16 recursions anyway.
+        */
+       if (G.var_nest_level > 0xff00)
+               bb_error_msg_and_die("fatal recursion (depth %u)", G.var_nest_level);
+}
+
+static void leave_var_nest_level(void)
+{
+       G.var_nest_level--;
+       debug_printf_env("var_nest_level-- %u\n", G.var_nest_level);
+       if (HUSH_DEBUG && (int)G.var_nest_level < 0)
+               bb_simple_error_msg_and_die("BUG: nesting underflow");
+
+       remove_nested_vars();
+}
+
+#if ENABLE_HUSH_FUNCTIONS
+static struct function **find_function_slot(const char *name)
+{
+       struct function *funcp;
+       struct function **funcpp = &G.top_func;
+
+       while ((funcp = *funcpp) != NULL) {
+               if (strcmp(name, funcp->name) == 0) {
+                       debug_printf_exec("found function '%s'\n", name);
+                       break;
+               }
+               funcpp = &funcp->next;
+       }
+       return funcpp;
+}
+
+static ALWAYS_INLINE const struct function *find_function(const char *name)
+{
+       const struct function *funcp = *find_function_slot(name);
+       return funcp;
+}
+
+/* Note: takes ownership on name ptr */
+static struct function *new_function(char *name)
+{
+       struct function **funcpp = find_function_slot(name);
+       struct function *funcp = *funcpp;
+
+       if (funcp != NULL) {
+               struct command *cmd = funcp->parent_cmd;
+               debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
+               if (!cmd) {
+                       debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
+                       free(funcp->name);
+                       /* Note: if !funcp->body, do not free body_as_string!
+                        * This is a special case of "-F name body" function:
+                        * body_as_string was not malloced! */
+                       if (funcp->body) {
+                               free_pipe_list(funcp->body);
+# if !BB_MMU
+                               free(funcp->body_as_string);
+# endif
+                       }
+               } else {
+                       debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
+                       cmd->argv[0] = funcp->name;
+                       cmd->group = funcp->body;
+# if !BB_MMU
+                       cmd->group_as_string = funcp->body_as_string;
+# endif
+               }
+       } else {
+               debug_printf_exec("remembering new function '%s'\n", name);
+               funcp = *funcpp = xzalloc(sizeof(*funcp));
+               /*funcp->next = NULL;*/
+       }
+
+       funcp->name = name;
+       return funcp;
+}
+
+# if ENABLE_HUSH_UNSET
+static void unset_func(const char *name)
+{
+       struct function **funcpp = find_function_slot(name);
+       struct function *funcp = *funcpp;
+
+       if (funcp != NULL) {
+               debug_printf_exec("freeing function '%s'\n", funcp->name);
+               *funcpp = funcp->next;
+               /* funcp is unlinked now, deleting it.
+                * Note: if !funcp->body, the function was created by
+                * "-F name body", do not free ->body_as_string
+                * and ->name as they were not malloced. */
+               if (funcp->body) {
+                       free_pipe_list(funcp->body);
+                       free(funcp->name);
+#  if !BB_MMU
+                       free(funcp->body_as_string);
+#  endif
+               }
+               free(funcp);
+       }
+}
+# endif
+
+# if BB_MMU
+#define exec_function(to_free, funcp, argv) \
+       exec_function(funcp, argv)
+# endif
+static void exec_function(char ***to_free,
+               const struct function *funcp,
+               char **argv) NORETURN;
+static void exec_function(char ***to_free,
+               const struct function *funcp,
+               char **argv)
+{
+# if BB_MMU
+       int n;
+
+       argv[0] = G.global_argv[0];
+       G.global_argv = argv;
+       G.global_argc = n = 1 + string_array_len(argv + 1);
+
+// Example when we are here: "cmd | func"
+// func will run with saved-redirect fds open.
+// $ f() { echo /proc/self/fd/*; }
+// $ true | f
+// /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3
+// stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ DIR fd for glob
+// Same in script:
+// $ . ./SCRIPT
+// /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3 /proc/self/fd/4
+// stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ opened ./SCRIPT DIR fd for glob
+// They are CLOEXEC so external programs won't see them, but
+// for "more correctness" we might want to close those extra fds here:
+//?    close_saved_fds_and_FILE_fds();
+
+       /* "we are in a function, ok to use return" */
+       G_flag_return_in_progress = -1;
+       enter_var_nest_level();
+       IF_HUSH_LOCAL(G.func_nest_level++;)
+
+       /* On MMU, funcp->body is always non-NULL */
+       n = run_list(funcp->body);
+       _exit(n);
+# else
+//?    close_saved_fds_and_FILE_fds();
+
+//TODO: check whether "true | func_with_return" works
+
+       re_execute_shell(to_free,
+                       funcp->body_as_string,
+                       G.global_argv[0],
+                       argv + 1,
+                       NULL);
+# endif
+}
+
+static int run_function(const struct function *funcp, char **argv)
+{
+       int rc;
+       save_arg_t sv;
+       smallint sv_flg;
+
+       save_and_replace_G_args(&sv, argv);
+
+       /* "We are in function, ok to use return" */
+       sv_flg = G_flag_return_in_progress;
+       G_flag_return_in_progress = -1;
+
+       /* Make "local" variables properly shadow previous ones */
+       IF_HUSH_LOCAL(enter_var_nest_level();)
+       IF_HUSH_LOCAL(G.func_nest_level++;)
+
+       /* On MMU, funcp->body is always non-NULL */
+# if !BB_MMU
+       if (!funcp->body) {
+               /* Function defined by -F */
+               parse_and_run_string(funcp->body_as_string);
+               rc = G.last_exitcode;
+       } else
+# endif
+       {
+               rc = run_list(funcp->body);
+       }
+
+       IF_HUSH_LOCAL(G.func_nest_level--;)
+       IF_HUSH_LOCAL(leave_var_nest_level();)
+
+       G_flag_return_in_progress = sv_flg;
+# if ENABLE_HUSH_TRAP
+       debug_printf_exec("G.return_exitcode=-1\n");
+       G.return_exitcode = -1; /* invalidate stashed return value */
+# endif
+
+       restore_G_args(&sv, argv);
+
+       return rc;
+}
+#endif /* ENABLE_HUSH_FUNCTIONS */
+
+
+#if BB_MMU
+#define exec_builtin(to_free, x, argv) \
+       exec_builtin(x, argv)
+#else
+#define exec_builtin(to_free, x, argv) \
+       exec_builtin(to_free, argv)
+#endif
+static void exec_builtin(char ***to_free,
+               const struct built_in_command *x,
+               char **argv) NORETURN;
+static void exec_builtin(char ***to_free,
+               const struct built_in_command *x,
+               char **argv)
+{
+#if BB_MMU
+       int rcode;
+//?    close_saved_fds_and_FILE_fds();
+       rcode = x->b_function(argv);
+       fflush_all();
+       _exit(rcode);
+#else
+       fflush_all();
+       /* On NOMMU, we must never block!
+        * Example: { sleep 99 | read line; } & echo Ok
+        */
+       re_execute_shell(to_free,
+                       argv[0],
+                       G.global_argv[0],
+                       G.global_argv + 1,
+                       argv);
+#endif
+}
+
+
+static void execvp_or_die(char **argv) NORETURN;
+static void execvp_or_die(char **argv)
+{
+       int e;
+       debug_printf_exec("execing '%s'\n", argv[0]);
+       /* Don't propagate SIG_IGN to the child */
+       if (SPECIAL_JOBSTOP_SIGS != 0)
+               switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
+       execvp(argv[0], argv);
+       e = 2;
+       if (errno == EACCES) e = 126;
+       if (errno == ENOENT) e = 127;
+       bb_perror_msg("can't execute '%s'", argv[0]);
+       _exit(e);
+}
+
+#if ENABLE_HUSH_MODE_X
+static void x_mode_print_optionally_squoted(const char *str)
+{
+       unsigned len;
+       const char *cp;
+
+       cp = str;
+
+       /* the set of chars which-cause-string-to-be-squoted mimics bash */
+       /* test a char with: bash -c 'set -x; echo "CH"' */
+       if (str[strcspn(str, "\\\"'`$(){}[]<>;#&|~*?!^"
+                       " " "\001\002\003\004\005\006\007"
+                       "\010\011\012\013\014\015\016\017"
+                       "\020\021\022\023\024\025\026\027"
+                       "\030\031\032\033\034\035\036\037"
+                       )
+               ] == '\0'
+       ) {
+               /* string has no special chars */
+               x_mode_addstr(str);
+               return;
+       }
+
+       cp = str;
+       for (;;) {
+               /* print '....' up to EOL or first squote */
+               len = (int)(strchrnul(cp, '\'') - cp);
+               if (len != 0) {
+                       x_mode_addchr('\'');
+                       x_mode_addblock(cp, len);
+                       x_mode_addchr('\'');
+                       cp += len;
+               }
+               if (*cp == '\0')
+                       break;
+               /* string contains squote(s), print them as \' */
+               x_mode_addchr('\\');
+               x_mode_addchr('\'');
+               cp++;
+       }
+}
+static void dump_cmd_in_x_mode(char **argv)
+{
+       if (G_x_mode && argv) {
+               unsigned n;
+
+               /* "+[+++...][ cmd...]\n\0" */
+               x_mode_prefix();
+               n = 0;
+               while (argv[n]) {
+                       x_mode_addchr(' ');
+                       if (argv[n][0] == '\0') {
+                               x_mode_addchr('\'');
+                               x_mode_addchr('\'');
+                       } else {
+                               x_mode_print_optionally_squoted(argv[n]);
+                       }
+                       n++;
+               }
+               x_mode_flush();
+       }
+}
+#else
+# define dump_cmd_in_x_mode(argv) ((void)0)
+#endif
+
+#if ENABLE_HUSH_COMMAND
+static void if_command_vV_print_and_exit(char opt_vV, char *cmd, const char *explanation)
+{
+       char *to_free;
+
+       if (!opt_vV)
+               return;
+
+       to_free = NULL;
+       if (!explanation) {
+               char *path = getenv("PATH");
+               explanation = to_free = find_executable(cmd, &path); /* path == NULL is ok */
+               if (!explanation)
+                       _exit(1); /* PROG was not found */
+               if (opt_vV != 'V')
+                       cmd = to_free; /* -v PROG prints "/path/to/PROG" */
+       }
+       printf((opt_vV == 'V') ? "%s is %s\n" : "%s\n", cmd, explanation);
+       free(to_free);
+       fflush_all();
+       _exit(0);
+}
+#else
+# define if_command_vV_print_and_exit(a,b,c) ((void)0)
+#endif
+
+#if BB_MMU
+#define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
+       pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
+#define pseudo_exec(nommu_save, command, argv_expanded) \
+       pseudo_exec(command, argv_expanded)
+#endif
+
+/* Called after [v]fork() in run_pipe, or from builtin_exec.
+ * Never returns.
+ * Don't exit() here.  If you don't exec, use _exit instead.
+ * The at_exit handlers apparently confuse the calling process,
+ * in particular stdin handling. Not sure why? -- because of vfork! (vda)
+ */
+static void pseudo_exec_argv(nommu_save_t *nommu_save,
+               char **argv, int assignment_cnt,
+               char **argv_expanded) NORETURN;
+static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
+               char **argv, int assignment_cnt,
+               char **argv_expanded)
+{
+       const struct built_in_command *x;
+       struct variable **sv_shadowed;
+       char **new_env;
+       IF_HUSH_COMMAND(char opt_vV = 0;)
+       IF_HUSH_FUNCTIONS(const struct function *funcp;)
+
+       new_env = expand_assignments(argv, assignment_cnt);
+       dump_cmd_in_x_mode(new_env);
+
+       if (!argv[assignment_cnt]) {
+               /* Case when we are here: ... | var=val | ...
+                * (note that we do not exit early, i.e., do not optimize out
+                * expand_assignments(): think about ... | var=`sleep 1` | ...
+                */
+               free_strings(new_env);
+               _exit(EXIT_SUCCESS);
+       }
+
+       sv_shadowed = G.shadowed_vars_pp;
+#if BB_MMU
+       G.shadowed_vars_pp = NULL; /* "don't save, free them instead" */
+#else
+       G.shadowed_vars_pp = &nommu_save->old_vars;
+       G.var_nest_level++;
+#endif
+       set_vars_and_save_old(new_env);
+       G.shadowed_vars_pp = sv_shadowed;
+
+       if (argv_expanded) {
+               argv = argv_expanded;
+       } else {
+               argv = expand_strvec_to_strvec(argv + assignment_cnt);
+#if !BB_MMU
+               nommu_save->argv = argv;
+#endif
+       }
+       dump_cmd_in_x_mode(argv);
+
+#if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
+       if (strchr(argv[0], '/') != NULL)
+               goto skip;
+#endif
+
+#if ENABLE_HUSH_FUNCTIONS
+       /* Check if the command matches any functions (this goes before bltins) */
+       funcp = find_function(argv[0]);
+       if (funcp)
+               exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
+#endif
+
+#if ENABLE_HUSH_COMMAND
+       /* "command BAR": run BAR without looking it up among functions
+        * "command -v BAR": print "BAR" or "/path/to/BAR"; or exit 1
+        * "command -V BAR": print "BAR is {a function,a shell builtin,/path/to/BAR}"
+        */
+       while (strcmp(argv[0], "command") == 0 && argv[1]) {
+               char *p;
+
+               argv++;
+               p = *argv;
+               if (p[0] != '-' || !p[1])
+                       continue; /* bash allows "command command command [-OPT] BAR" */
+
+               for (;;) {
+                       p++;
+                       switch (*p) {
+                       case '\0':
+                               argv++;
+                               p = *argv;
+                               if (p[0] != '-' || !p[1])
+                                       goto after_opts;
+                               continue; /* next arg is also -opts, process it too */
+                       case 'v':
+                       case 'V':
+                               opt_vV = *p;
+                               continue;
+                       default:
+                               bb_error_msg_and_die("%s: %s: invalid option", "command", argv[0]);
+                       }
+               }
+       }
+ after_opts:
+# if ENABLE_HUSH_FUNCTIONS
+       if (opt_vV && find_function(argv[0]))
+               if_command_vV_print_and_exit(opt_vV, argv[0], "a function");
+# endif
+#endif
+
+       /* Check if the command matches any of the builtins.
+        * Depending on context, this might be redundant.  But it's
+        * easier to waste a few CPU cycles than it is to figure out
+        * if this is one of those cases.
+        */
+       /* Why "BB_MMU ? :" difference in logic? -
+        * On NOMMU, it is more expensive to re-execute shell
+        * just in order to run echo or test builtin.
+        * It's better to skip it here and run corresponding
+        * non-builtin later. */
+       x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
+       if (x) {
+               if_command_vV_print_and_exit(opt_vV, argv[0], "a shell builtin");
+               exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
+       }
+
+#if ENABLE_FEATURE_SH_STANDALONE
+       /* Check if the command matches any busybox applets */
+       {
+               int a = find_applet_by_name(argv[0]);
+               if (a >= 0) {
+                       if_command_vV_print_and_exit(opt_vV, argv[0], "an applet");
+# if BB_MMU /* see above why on NOMMU it is not allowed */
+                       if (APPLET_IS_NOEXEC(a)) {
+                               /* Do not leak open fds from opened script files etc.
+                                * Testcase: interactive "ls -l /proc/self/fd"
+                                * should not show tty fd open.
+                                */
+                               close_saved_fds_and_FILE_fds();
+//FIXME: should also close saved redir fds
+//This casuses test failures in
+//redir_children_should_not_see_saved_fd_2.tests
+//redir_children_should_not_see_saved_fd_3.tests
+//if you replace "busybox find" with just "find" in them
+                               /* Without this, "rm -i FILE" can't be ^C'ed: */
+                               switch_off_special_sigs(G.special_sig_mask);
+                               debug_printf_exec("running applet '%s'\n", argv[0]);
+                               run_noexec_applet_and_exit(a, argv[0], argv);
+                       }
+# endif
+                       /* Re-exec ourselves */
+                       debug_printf_exec("re-execing applet '%s'\n", argv[0]);
+                       /* Don't propagate SIG_IGN to the child */
+                       if (SPECIAL_JOBSTOP_SIGS != 0)
+                               switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
+                       execv(bb_busybox_exec_path, argv);
+                       /* If they called chroot or otherwise made the binary no longer
+                        * executable, fall through */
+               }
+       }
+#endif
+
+#if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
+ skip:
+#endif
+       if_command_vV_print_and_exit(opt_vV, argv[0], NULL);
+       execvp_or_die(argv);
+}
+
+/* Called after [v]fork() in run_pipe
+ */
+static void pseudo_exec(nommu_save_t *nommu_save,
+               struct command *command,
+               char **argv_expanded) NORETURN;
+static void pseudo_exec(nommu_save_t *nommu_save,
+               struct command *command,
+               char **argv_expanded)
+{
+#if ENABLE_HUSH_FUNCTIONS
+       if (command->cmd_type == CMD_FUNCDEF) {
+               /* Ignore funcdefs in pipes:
+                * true | f() { cmd }
+                */
+               _exit(0);
+       }
+#endif
+
+       if (command->argv) {
+               pseudo_exec_argv(nommu_save, command->argv,
+                               command->assignment_cnt, argv_expanded);
+       }
+
+       if (command->group) {
+               /* Cases when we are here:
+                * ( list )
+                * { list } &
+                * ... | ( list ) | ...
+                * ... | { list } | ...
+                */
+#if BB_MMU
+               int rcode;
+               debug_printf_exec("pseudo_exec: run_list\n");
+               reset_traps_to_defaults();
+               rcode = run_list(command->group);
+               /* OK to leak memory by not calling free_pipe_list,
+                * since this process is about to exit */
+               _exit(rcode);
+#else
+               re_execute_shell(&nommu_save->argv_from_re_execing,
+                               command->group_as_string,
+                               G.global_argv[0],
+                               G.global_argv + 1,
+                               NULL);
+#endif
+       }
+
+       /* Case when we are here: ... | >file */
+       debug_printf_exec("pseudo_exec'ed null command\n");
+       _exit(EXIT_SUCCESS);
+}
+
+#if ENABLE_HUSH_JOB
+static const char *get_cmdtext(struct pipe *pi)
+{
+       char **argv;
+       char *p;
+       int len;
+
+       /* This is subtle. ->cmdtext is created only on first backgrounding.
+        * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
+        * On subsequent bg argv is trashed, but we won't use it */
+       if (pi->cmdtext)
+               return pi->cmdtext;
+
+       argv = pi->cmds[0].argv;
+       if (!argv) {
+               pi->cmdtext = xzalloc(1);
+               return pi->cmdtext;
+       }
+       len = 0;
+       do {
+               len += strlen(*argv) + 1;
+       } while (*++argv);
+       p = xmalloc(len);
+       pi->cmdtext = p;
+       argv = pi->cmds[0].argv;
+       do {
+               p = stpcpy(p, *argv);
+               *p++ = ' ';
+       } while (*++argv);
+       p[-1] = '\0';
+       return pi->cmdtext;
+}
+
+static void remove_job_from_table(struct pipe *pi)
+{
+       struct pipe *prev_pipe;
+
+       if (pi == G.job_list) {
+               G.job_list = pi->next;
+       } else {
+               prev_pipe = G.job_list;
+               while (prev_pipe->next != pi)
+                       prev_pipe = prev_pipe->next;
+               prev_pipe->next = pi->next;
+       }
+       G.last_jobid = 0;
+       if (G.job_list)
+               G.last_jobid = G.job_list->jobid;
+}
+
+static void delete_finished_job(struct pipe *pi)
+{
+       remove_job_from_table(pi);
+       free_pipe(pi);
+}
+
+static void clean_up_last_dead_job(void)
+{
+       if (G.job_list && !G.job_list->alive_cmds)
+               delete_finished_job(G.job_list);
+}
+
+static void insert_job_into_table(struct pipe *pi)
+{
+       struct pipe *job, **jobp;
+       int i;
+
+       clean_up_last_dead_job();
+
+       /* Find the end of the list, and find next job ID to use */
+       i = 0;
+       jobp = &G.job_list;
+       while ((job = *jobp) != NULL) {
+               if (job->jobid > i)
+                       i = job->jobid;
+               jobp = &job->next;
+       }
+       pi->jobid = i + 1;
+
+       /* Create a new job struct at the end */
+       job = *jobp = xmemdup(pi, sizeof(*pi));
+       job->next = NULL;
+       job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
+       /* Cannot copy entire pi->cmds[] vector! This causes double frees */
+       for (i = 0; i < pi->num_cmds; i++) {
+               job->cmds[i].pid = pi->cmds[i].pid;
+               /* all other fields are not used and stay zero */
+       }
+       job->cmdtext = xstrdup(get_cmdtext(pi));
+
+       if (G_interactive_fd)
+               printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
+       G.last_jobid = job->jobid;
+}
+#endif /* JOB */
+
+static int job_exited_or_stopped(struct pipe *pi)
+{
+       int rcode, i;
+
+       if (pi->alive_cmds != pi->stopped_cmds)
+               return -1;
+
+       /* All processes in fg pipe have exited or stopped */
+       rcode = 0;
+       i = pi->num_cmds;
+       while (--i >= 0) {
+               rcode = pi->cmds[i].cmd_exitcode;
+               /* usually last process gives overall exitstatus,
+                * but with "set -o pipefail", last *failed* process does */
+               if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
+                       break;
+       }
+       IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
+       return rcode;
+}
+
+static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
+{
+#if ENABLE_HUSH_JOB
+       struct pipe *pi;
+#endif
+       int i, dead;
+
+       dead = WIFEXITED(status) || WIFSIGNALED(status);
+
+#if DEBUG_JOBS
+       if (WIFSTOPPED(status))
+               debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
+                               childpid, WSTOPSIG(status), WEXITSTATUS(status));
+       if (WIFSIGNALED(status))
+               debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
+                               childpid, WTERMSIG(status), WEXITSTATUS(status));
+       if (WIFEXITED(status))
+               debug_printf_jobs("pid %d exited, exitcode %d\n",
+                               childpid, WEXITSTATUS(status));
+#endif
+       /* Were we asked to wait for a fg pipe? */
+       if (fg_pipe) {
+               i = fg_pipe->num_cmds;
+
+               while (--i >= 0) {
+                       int rcode;
+
+                       debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
+                       if (fg_pipe->cmds[i].pid != childpid)
+                               continue;
+                       if (dead) {
+                               int ex;
+                               fg_pipe->cmds[i].pid = 0;
+                               fg_pipe->alive_cmds--;
+                               ex = WEXITSTATUS(status);
+                               /* bash prints killer signal's name for *last*
+                                * process in pipe (prints just newline for SIGINT/SIGPIPE).
+                                * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
+                                */
+                               if (WIFSIGNALED(status)) {
+                                       int sig = WTERMSIG(status);
+#if ENABLE_HUSH_JOB
+                                       if (G.run_list_level == 1
+                                       /* ^^^^^ Do not print in nested contexts, example:
+                                        * echo `sleep 1; sh -c 'kill -9 $$'` - prints "137", NOT "Killed 137"
+                                        */
+                                        && i == fg_pipe->num_cmds-1
+                                       ) {
+                                               /* strsignal() is for bash compat. ~600 bloat versus bbox's get_signame() */
+                                               puts(sig == SIGINT || sig == SIGPIPE ? "" : strsignal(sig));
+                                       }
+#endif
+                                       /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
+                                       /* MIPS has 128 sigs (1..128), if sig==128,
+                                        * 128 + sig would result in exitcode 256 -> 0!
+                                        */
+                                       ex = 128 | sig;
+                               }
+                               fg_pipe->cmds[i].cmd_exitcode = ex;
+                       } else {
+                               fg_pipe->stopped_cmds++;
+                       }
+                       debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
+                                       fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
+                       rcode = job_exited_or_stopped(fg_pipe);
+                       if (rcode >= 0) {
+/* Note: *non-interactive* bash does not continue if all processes in fg pipe
+ * are stopped. Testcase: "cat | cat" in a script (not on command line!)
+ * and "killall -STOP cat" */
+                               if (G_interactive_fd) {
+#if ENABLE_HUSH_JOB
+                                       if (fg_pipe->alive_cmds != 0)
+                                               insert_job_into_table(fg_pipe);
+#endif
+                                       return rcode;
+                               }
+                               if (fg_pipe->alive_cmds == 0)
+                                       return rcode;
+                       }
+                       /* There are still running processes in the fg_pipe */
+                       return -1;
+               }
+               /* It wasn't in fg_pipe, look for process in bg pipes */
+       }
+
+#if ENABLE_HUSH_JOB
+       /* We were asked to wait for bg or orphaned children */
+       /* No need to remember exitcode in this case */
+       for (pi = G.job_list; pi; pi = pi->next) {
+               for (i = 0; i < pi->num_cmds; i++) {
+                       if (pi->cmds[i].pid == childpid)
+                               goto found_pi_and_prognum;
+               }
+       }
+       /* Happens when shell is used as init process (init=/bin/sh) */
+       debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
+       return -1; /* this wasn't a process from fg_pipe */
+
+ found_pi_and_prognum:
+       if (dead) {
+               /* child exited */
+               int rcode = WEXITSTATUS(status);
+               if (WIFSIGNALED(status))
+                       /* NB: not 128 + sig, MIPS has sig 128 */
+                       rcode = 128 | WTERMSIG(status);
+               pi->cmds[i].cmd_exitcode = rcode;
+               if (G.last_bg_pid == pi->cmds[i].pid)
+                       G.last_bg_pid_exitcode = rcode;
+               pi->cmds[i].pid = 0;
+               pi->alive_cmds--;
+               if (!pi->alive_cmds) {
+# if ENABLE_HUSH_BASH_COMPAT
+                       G.dead_job_exitcode = job_exited_or_stopped(pi);
+# endif
+                       if (G_interactive_fd) {
+                               printf(JOB_STATUS_FORMAT, pi->jobid,
+                                               "Done", pi->cmdtext);
+                               delete_finished_job(pi);
+                       } else {
+/*
+ * bash deletes finished jobs from job table only in interactive mode,
+ * after "jobs" cmd, or if pid of a new process matches one of the old ones
+ * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
+ * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
+ * We only retain one "dead" job, if it's the single job on the list.
+ * This covers most of real-world scenarios where this is useful.
+ */
+                               if (pi != G.job_list)
+                                       delete_finished_job(pi);
+                       }
+               }
+       } else {
+               /* child stopped */
+               pi->stopped_cmds++;
+       }
+#endif
+       return -1; /* this wasn't a process from fg_pipe */
+}
+
+/* Check to see if any processes have exited -- if they have,
+ * figure out why and see if a job has completed.
+ *
+ * If non-NULL fg_pipe: wait for its completion or stop.
+ * Return its exitcode or zero if stopped.
+ *
+ * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
+ * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
+ * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
+ * or 0 if no children changed status.
+ *
+ * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
+ * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
+ * or 0 if no children changed status.
+ */
+static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
+{
+       int attributes;
+       int status;
+       int rcode = 0;
+
+       debug_printf_jobs("checkjobs %p\n", fg_pipe);
+
+       attributes = WUNTRACED;
+       if (fg_pipe == NULL)
+               attributes |= WNOHANG;
+
+       errno = 0;
+#if ENABLE_HUSH_FAST
+       if (G.handled_SIGCHLD == G.count_SIGCHLD) {
+//bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
+//getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
+               /* There was neither fork nor SIGCHLD since last waitpid */
+               /* Avoid doing waitpid syscall if possible */
+               if (!G.we_have_children) {
+                       errno = ECHILD;
+                       return -1;
+               }
+               if (fg_pipe == NULL) { /* is WNOHANG set? */
+                       /* We have children, but they did not exit
+                        * or stop yet (we saw no SIGCHLD) */
+                       return 0;
+               }
+               /* else: !WNOHANG, waitpid will block, can't short-circuit */
+       }
+#endif
+
+/* Do we do this right?
+ * bash-3.00# sleep 20 | false
+ * <ctrl-Z pressed>
+ * [3]+  Stopped          sleep 20 | false
+ * bash-3.00# echo $?
+ * 1   <========== bg pipe is not fully done, but exitcode is already known!
+ * [hush 1.14.0: yes we do it right]
+ */
+       while (1) {
+               pid_t childpid;
+#if ENABLE_HUSH_FAST
+               int i;
+               i = G.count_SIGCHLD;
+#endif
+               childpid = waitpid(-1, &status, attributes);
+               if (childpid <= 0) {
+                       if (childpid && errno != ECHILD)
+                               bb_simple_perror_msg("waitpid");
+#if ENABLE_HUSH_FAST
+                       else { /* Until next SIGCHLD, waitpid's are useless */
+                               G.we_have_children = (childpid == 0);
+                               G.handled_SIGCHLD = i;
+//bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
+                       }
+#endif
+                       /* ECHILD (no children), or 0 (no change in children status) */
+                       rcode = childpid;
+                       break;
+               }
+               rcode = process_wait_result(fg_pipe, childpid, status);
+               if (rcode >= 0) {
+                       /* fg_pipe exited or stopped */
+                       break;
+               }
+               if (childpid == waitfor_pid) { /* "wait PID" */
+                       debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
+                       rcode = WEXITSTATUS(status);
+                       if (WIFSIGNALED(status))
+                               rcode = 128 | WTERMSIG(status);
+                       if (WIFSTOPPED(status))
+                               /* bash: "cmd & wait $!" and cmd stops: $? = 128 | stopsig */
+                               rcode = 128 | WSTOPSIG(status);
+                       rcode++;
+                       break; /* "wait PID" called us, give it exitcode+1 */
+               }
+#if ENABLE_HUSH_BASH_COMPAT
+               if (-1 == waitfor_pid /* "wait -n" (wait for any one job) */
+                && G.dead_job_exitcode >= 0 /* some job did finish */
+               ) {
+                       debug_printf_exec("waitfor_pid:-1\n");
+                       rcode = G.dead_job_exitcode + 1;
+                       break;
+               }
+#endif
+               /* This wasn't one of our processes, or */
+               /* fg_pipe still has running processes, do waitpid again */
+       } /* while (waitpid succeeds)... */
+
+       return rcode;
+}
+
+#if ENABLE_HUSH_JOB
+static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
+{
+       pid_t p;
+       int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
+       if (G_saved_tty_pgrp) {
+               /* Job finished, move the shell to the foreground */
+               p = getpgrp(); /* our process group id */
+               debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
+               tcsetpgrp(G_interactive_fd, p);
+       }
+       return rcode;
+}
+#endif
+
+/* Start all the jobs, but don't wait for anything to finish.
+ * See checkjobs().
+ *
+ * Return code is normally -1, when the caller has to wait for children
+ * to finish to determine the exit status of the pipe.  If the pipe
+ * is a simple builtin command, however, the action is done by the
+ * time run_pipe returns, and the exit code is provided as the
+ * return value.
+ *
+ * Returns -1 only if started some children. IOW: we have to
+ * mask out retvals of builtins etc with 0xff!
+ *
+ * The only case when we do not need to [v]fork is when the pipe
+ * is single, non-backgrounded, non-subshell command. Examples:
+ * cmd ; ...   { list } ; ...
+ * cmd && ...  { list } && ...
+ * cmd || ...  { list } || ...
+ * If it is, then we can run cmd as a builtin, NOFORK,
+ * or (if SH_STANDALONE) an applet, and we can run the { list }
+ * with run_list. If it isn't one of these, we fork and exec cmd.
+ *
+ * Cases when we must fork:
+ * non-single:   cmd | cmd
+ * backgrounded: cmd &     { list } &
+ * subshell:     ( list ) [&]
+ */
+#if !ENABLE_HUSH_MODE_X
+#define redirect_and_varexp_helper(command, sqp, argv_expanded) \
+       redirect_and_varexp_helper(command, sqp)
+#endif
+static int redirect_and_varexp_helper(
+               struct command *command,
+               struct squirrel **sqp,
+               char **argv_expanded)
+{
+       /* Assignments occur before redirects. Try:
+        * a=`sleep 1` sleep 2 3>/qwe/rty
+        */
+
+       char **new_env = expand_assignments(command->argv, command->assignment_cnt);
+       dump_cmd_in_x_mode(new_env);
+       dump_cmd_in_x_mode(argv_expanded);
+       /* this takes ownership of new_env[i] elements, and frees new_env: */
+       set_vars_and_save_old(new_env);
+
+       return setup_redirects(command, sqp);
+}
+static NOINLINE int run_pipe(struct pipe *pi)
+{
+       static const char *const null_ptr = NULL;
+
+       int cmd_no;
+       int next_infd;
+       struct command *command;
+       char **argv_expanded;
+       char **argv;
+       struct squirrel *squirrel = NULL;
+       int rcode;
+
+       debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
+       debug_enter();
+
+       /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
+        * Result should be 3 lines: q w e, qwe, q w e
+        */
+       if (G.ifs_whitespace != G.ifs)
+               free(G.ifs_whitespace);
+       G.ifs = get_local_var_value("IFS");
+       if (G.ifs) {
+               char *p;
+               G.ifs_whitespace = (char*)G.ifs;
+               p = skip_whitespace(G.ifs);
+               if (*p) {
+                       /* Not all $IFS is whitespace */
+                       char *d;
+                       int len = p - G.ifs;
+                       p = skip_non_whitespace(p);
+                       G.ifs_whitespace = xmalloc(len + strlen(p) + 1); /* can overestimate */
+                       d = mempcpy(G.ifs_whitespace, G.ifs, len);
+                       while (*p) {
+                               if (isspace(*p))
+                                       *d++ = *p;
+                               p++;
+                       }
+                       *d = '\0';
+               }
+       } else {
+               G.ifs = defifs;
+               G.ifs_whitespace = (char*)G.ifs;
+       }
+
+       IF_HUSH_JOB(pi->pgrp = -1;)
+       pi->stopped_cmds = 0;
+       command = &pi->cmds[0];
+       argv_expanded = NULL;
+
+       if (pi->num_cmds != 1
+        || pi->followup == PIPE_BG
+        || command->cmd_type == CMD_SUBSHELL
+       ) {
+               goto must_fork;
+       }
+
+       pi->alive_cmds = 1;
+
+       debug_printf_exec(": group:%p argv:'%s'\n",
+               command->group, command->argv ? command->argv[0] : "NONE");
+
+       if (command->group) {
+#if ENABLE_HUSH_FUNCTIONS
+               if (command->cmd_type == CMD_FUNCDEF) {
+                       /* "executing" func () { list } */
+                       struct function *funcp;
+
+                       funcp = new_function(command->argv[0]);
+                       /* funcp->name is already set to argv[0] */
+                       funcp->body = command->group;
+# if !BB_MMU
+                       funcp->body_as_string = command->group_as_string;
+                       command->group_as_string = NULL;
+# endif
+                       command->group = NULL;
+                       command->argv[0] = NULL;
+                       debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
+                       funcp->parent_cmd = command;
+                       command->child_func = funcp;
+
+                       debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
+                       debug_leave();
+                       return EXIT_SUCCESS;
+               }
+#endif
+               /* { list } */
+               debug_printf_exec("non-subshell group\n");
+               rcode = 1; /* exitcode if redir failed */
+               if (setup_redirects(command, &squirrel) == 0) {
+                       debug_printf_exec(": run_list\n");
+//FIXME: we need to pass squirrel down into run_list()
+//for SH_STANDALONE case, or else this construct:
+// { find /proc/self/fd; true; } >FILE; cmd2
+//has no way of closing saved fd#1 for "find",
+//and in SH_STANDALONE mode, "find" is not execed,
+//therefore CLOEXEC on saved fd does not help.
+                       rcode = run_list(command->group) & 0xff;
+               }
+               restore_redirects(squirrel);
+               IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
+               debug_leave();
+               debug_printf_exec("run_pipe: return %d\n", rcode);
+               return rcode;
+       }
+
+       argv = command->argv ? command->argv : (char **) &null_ptr;
+       {
+               const struct built_in_command *x;
+               IF_HUSH_FUNCTIONS(const struct function *funcp;)
+               IF_NOT_HUSH_FUNCTIONS(enum { funcp = 0 };)
+               struct variable **sv_shadowed;
+               struct variable *old_vars;
+
+#if ENABLE_HUSH_LINENO_VAR
+               G.execute_lineno = command->lineno;
+#endif
+
+               if (argv[command->assignment_cnt] == NULL) {
+                       /* Assignments, but no command.
+                        * Ensure redirects take effect (that is, create files).
+                        * Try "a=t >file"
+                        */
+                       unsigned i;
+                       G.expand_exitcode = 0;
+ only_assignments:
+                       rcode = setup_redirects(command, &squirrel);
+                       restore_redirects(squirrel);
+
+                       /* Set shell variables */
+                       i = 0;
+                       while (i < command->assignment_cnt) {
+                               char *p = expand_string_to_string(argv[i],
+                                               EXP_FLAG_ESC_GLOB_CHARS,
+                                               /*unbackslash:*/ 1
+                               );
+#if ENABLE_HUSH_MODE_X
+                               if (G_x_mode) {
+                                       char *eq;
+                                       if (i == 0)
+                                               x_mode_prefix();
+                                       x_mode_addchr(' ');
+                                       eq = strchrnul(p, '=');
+                                       if (*eq) eq++;
+                                       x_mode_addblock(p, (eq - p));
+                                       x_mode_print_optionally_squoted(eq);
+                                       x_mode_flush();
+                               }
+#endif
+                               debug_printf_env("set shell var:'%s'->'%s'\n", *argv, p);
+                               if (set_local_var(p, /*flag:*/ 0)) {
+                                       /* assignment to readonly var / putenv error? */
+                                       rcode = 1;
+                               }
+                               i++;
+                       }
+                       /* Redirect error sets $? to 1. Otherwise,
+                        * if evaluating assignment value set $?, retain it.
+                        * Else, clear $?:
+                        *  false; q=`exit 2`; echo $? - should print 2
+                        *  false; x=1; echo $? - should print 0
+                        * Because of the 2nd case, we can't just use G.last_exitcode.
+                        */
+                       if (rcode == 0)
+                               rcode = G.expand_exitcode;
+                       IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
+                       debug_leave();
+                       debug_printf_exec("run_pipe: return %d\n", rcode);
+                       return rcode;
+               }
+
+               /* Expand the rest into (possibly) many strings each */
+#if defined(CMD_TEST2_SINGLEWORD_NOGLOB)
+               if (command->cmd_type == CMD_TEST2_SINGLEWORD_NOGLOB)
+                       argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
+               else
+#endif
+#if defined(CMD_SINGLEWORD_NOGLOB)
+               if (command->cmd_type == CMD_SINGLEWORD_NOGLOB)
+                       argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
+               else
+#endif
+                       argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
+
+               /* If someone gives us an empty string: `cmd with empty output` */
+               if (!argv_expanded[0]) {
+                       free(argv_expanded);
+                       /* `false` still has to set exitcode 1 */
+                       G.expand_exitcode = G.last_exitcode;
+                       goto only_assignments;
+               }
+
+               old_vars = NULL;
+               sv_shadowed = G.shadowed_vars_pp;
+
+               /* Check if argv[0] matches any functions (this goes before bltins) */
+               IF_HUSH_FUNCTIONS(funcp = find_function(argv_expanded[0]);)
+               IF_HUSH_FUNCTIONS(x = NULL;)
+               IF_HUSH_FUNCTIONS(if (!funcp))
+                       x = find_builtin(argv_expanded[0]);
+               if (x || funcp) {
+                       if (x && x->b_function == builtin_exec && argv_expanded[1] == NULL) {
+                               debug_printf("exec with redirects only\n");
+                               /*
+                                * Variable assignments are executed, but then "forgotten":
+                                *  a=`sleep 1;echo A` exec 3>&-; echo $a
+                                * sleeps, but prints nothing.
+                                */
+                               enter_var_nest_level();
+                               G.shadowed_vars_pp = &old_vars;
+                               rcode = redirect_and_varexp_helper(command,
+                                       /*squirrel:*/ ERR_PTR,
+                                       argv_expanded
+                               );
+                               G.shadowed_vars_pp = sv_shadowed;
+                               /* rcode=1 can be if redir file can't be opened */
+
+                               goto clean_up_and_ret1;
+                       }
+
+                       /* Bump var nesting, or this will leak exported $a:
+                        * a=b true; env | grep ^a=
+                        */
+                       enter_var_nest_level();
+                       /* Collect all variables "shadowed" by helper
+                        * (IOW: old vars overridden by "var1=val1 var2=val2 cmd..." syntax)
+                        * into old_vars list:
+                        */
+                       G.shadowed_vars_pp = &old_vars;
+                       rcode = redirect_and_varexp_helper(command, &squirrel, argv_expanded);
+                       if (rcode == 0) {
+                               if (!funcp) {
+                                       /* Do not collect *to old_vars list* vars shadowed
+                                        * by e.g. "local VAR" builtin (collect them
+                                        * in the previously nested list instead):
+                                        * don't want them to be restored immediately
+                                        * after "local" completes.
+                                        */
+                                       G.shadowed_vars_pp = sv_shadowed;
+
+                                       debug_printf_exec(": builtin '%s' '%s'...\n",
+                                               x->b_cmd, argv_expanded[1]);
+                                       fflush_all();
+                                       rcode = x->b_function(argv_expanded) & 0xff;
+                                       fflush_all();
+                               }
+#if ENABLE_HUSH_FUNCTIONS
+                               else {
+                                       debug_printf_exec(": function '%s' '%s'...\n",
+                                               funcp->name, argv_expanded[1]);
+                                       rcode = run_function(funcp, argv_expanded) & 0xff;
+                                       /*
+                                        * But do collect *to old_vars list* vars shadowed
+                                        * within function execution. To that end, restore
+                                        * this pointer _after_ function run:
+                                        */
+                                       G.shadowed_vars_pp = sv_shadowed;
+                               }
+#endif
+                       }
+               } else
+               if (ENABLE_FEATURE_SH_NOFORK && NUM_APPLETS > 1) {
+                       int n = find_applet_by_name(argv_expanded[0]);
+                       if (n < 0 || !APPLET_IS_NOFORK(n))
+                               goto must_fork;
+
+                       enter_var_nest_level();
+                       /* Collect all variables "shadowed" by helper into old_vars list */
+                       G.shadowed_vars_pp = &old_vars;
+                       rcode = redirect_and_varexp_helper(command, &squirrel, argv_expanded);
+                       G.shadowed_vars_pp = sv_shadowed;
+
+                       if (rcode == 0) {
+                               debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
+                                       argv_expanded[0], argv_expanded[1]);
+                               /*
+                                * Note: signals (^C) can't interrupt here.
+                                * We remember them and they will be acted upon
+                                * after applet returns.
+                                * This makes applets which can run for a long time
+                                * and/or wait for user input ineligible for NOFORK:
+                                * for example, "yes" or "rm" (rm -i waits for input).
+                                */
+                               rcode = run_nofork_applet(n, argv_expanded);
+                       }
+               } else
+                       goto must_fork;
+
+               restore_redirects(squirrel);
+ clean_up_and_ret1:
+               leave_var_nest_level();
+               add_vars(old_vars);
+
+               /*
+                * Try "usleep 99999999" + ^C + "echo $?"
+                * with FEATURE_SH_NOFORK=y.
+                */
+               if (!funcp) {
+                       /* It was builtin or nofork.
+                        * if this would be a real fork/execed program,
+                        * it should have died if a fatal sig was received.
+                        * But OTOH, there was no separate process,
+                        * the sig was sent to _shell_, not to non-existing
+                        * child.
+                        * Let's just handle ^C only, this one is obvious:
+                        * we aren't ok with exitcode 0 when ^C was pressed
+                        * during builtin/nofork.
+                        */
+                       if (sigismember(&G.pending_set, SIGINT))
+                               rcode = 128 | SIGINT;
+               }
+               free(argv_expanded);
+               IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
+               debug_leave();
+               debug_printf_exec("run_pipe return %d\n", rcode);
+               return rcode;
+       }
+
+ must_fork:
+       /* NB: argv_expanded may already be created, and that
+        * might include `cmd` runs! Do not rerun it! We *must*
+        * use argv_expanded if it's non-NULL */
+
+       /* Going to fork a child per each pipe member */
+       pi->alive_cmds = 0;
+       next_infd = 0;
+
+       cmd_no = 0;
+       while (cmd_no < pi->num_cmds) {
+               struct fd_pair pipefds;
+#if !BB_MMU
+               int sv_var_nest_level = G.var_nest_level;
+               volatile nommu_save_t nommu_save;
+               nommu_save.old_vars = NULL;
+               nommu_save.argv = NULL;
+               nommu_save.argv_from_re_execing = NULL;
+#endif
+               command = &pi->cmds[cmd_no];
+               cmd_no++;
+               if (command->argv) {
+                       debug_printf_exec(": pipe member '%s' '%s'...\n",
+                                       command->argv[0], command->argv[1]);
+               } else {
+                       debug_printf_exec(": pipe member with no argv\n");
+               }
+
+               /* pipes are inserted between pairs of commands */
+               pipefds.rd = 0;
+               pipefds.wr = 1;
+               if (cmd_no < pi->num_cmds)
+                       xpiped_pair(pipefds);
+
+#if ENABLE_HUSH_LINENO_VAR
+               G.execute_lineno = command->lineno;
+#endif
+
+               command->pid = BB_MMU ? fork() : vfork();
+               if (!command->pid) { /* child */
+#if ENABLE_HUSH_JOB
+                       disable_restore_tty_pgrp_on_exit();
+                       CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
+
+                       /* Every child adds itself to new process group
+                        * with pgid == pid_of_first_child_in_pipe */
+                       if (G.run_list_level == 1 && G_interactive_fd) {
+                               pid_t pgrp;
+                               pgrp = pi->pgrp;
+                               if (pgrp < 0) /* true for 1st process only */
+                                       pgrp = getpid();
+                               if (setpgid(0, pgrp) == 0
+                                && pi->followup != PIPE_BG
+                                && G_saved_tty_pgrp /* we have ctty */
+                               ) {
+                                       /* We do it in *every* child, not just first,
+                                        * to avoid races */
+                                       tcsetpgrp(G_interactive_fd, pgrp);
+                               }
+                       }
+#endif
+                       if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
+                               /* 1st cmd in backgrounded pipe
+                                * should have its stdin /dev/null'ed */
+                               close(0);
+                               if (open(bb_dev_null, O_RDONLY))
+                                       xopen("/", O_RDONLY);
+                       } else {
+                               xmove_fd(next_infd, 0);
+                       }
+                       xmove_fd(pipefds.wr, 1);
+                       if (pipefds.rd > 1)
+                               close(pipefds.rd);
+                       /* Like bash, explicit redirects override pipes,
+                        * and the pipe fd (fd#1) is available for dup'ing:
+                        * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
+                        * of cmd1 goes into pipe.
+                        */
+                       if (setup_redirects(command, NULL)) {
+                               /* Happens when redir file can't be opened:
+                                * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
+                                * FOO
+                                * hush: can't open '/qwe/rty': No such file or directory
+                                * BAZ
+                                * (echo BAR is not executed, it hits _exit(1) below)
+                                */
+                               _exit(1);
+                       }
+
+                       /* Stores to nommu_save list of env vars putenv'ed
+                        * (NOMMU, on MMU we don't need that) */
+                       /* cast away volatility... */
+                       pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
+                       /* pseudo_exec() does not return */
+               }
+
+               /* parent or error */
+#if ENABLE_HUSH_FAST
+               G.count_SIGCHLD++;
+//bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
+#endif
+               enable_restore_tty_pgrp_on_exit();
+#if !BB_MMU
+               /* Clean up after vforked child */
+               free(nommu_save.argv);
+               free(nommu_save.argv_from_re_execing);
+               G.var_nest_level = sv_var_nest_level;
+               remove_nested_vars();
+               add_vars(nommu_save.old_vars);
+#endif
+               free(argv_expanded);
+               argv_expanded = NULL;
+               if (command->pid < 0) { /* [v]fork failed */
+                       /* Clearly indicate, was it fork or vfork */
+                       bb_simple_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
+               } else {
+                       pi->alive_cmds++;
+#if ENABLE_HUSH_JOB
+                       /* Second and next children need to know pid of first one */
+                       if (pi->pgrp < 0)
+                               pi->pgrp = command->pid;
+#endif
+               }
+
+               if (cmd_no > 1)
+                       close(next_infd);
+               if (cmd_no < pi->num_cmds)
+                       close(pipefds.wr);
+               /* Pass read (output) pipe end to next iteration */
+               next_infd = pipefds.rd;
+       }
+
+       if (!pi->alive_cmds) {
+               debug_leave();
+               debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
+               return 1;
+       }
+
+       debug_leave();
+       debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
+       return -1;
+}
+
+/* NB: called by pseudo_exec, and therefore must not modify any
+ * global data until exec/_exit (we can be a child after vfork!) */
+static int run_list(struct pipe *pi)
+{
+#if ENABLE_HUSH_CASE
+       char *case_word = NULL;
+#endif
+#if ENABLE_HUSH_LOOPS
+       struct pipe *loop_top = NULL;
+       char **for_lcur = NULL;
+       char **for_list = NULL;
+#endif
+       smallint last_followup;
+       smalluint rcode;
+#if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
+       smalluint cond_code = 0;
+#else
+       enum { cond_code = 0 };
+#endif
+#if HAS_KEYWORDS
+       smallint rword;      /* RES_foo */
+       smallint last_rword; /* ditto */
+#endif
+
+       debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
+       debug_enter();
+
+#if ENABLE_HUSH_LOOPS
+       /* Check syntax for "for" */
+       {
+               struct pipe *cpipe;
+               for (cpipe = pi; cpipe; cpipe = cpipe->next) {
+                       if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
+                               continue;
+                       /* current word is FOR or IN (BOLD in comments below) */
+                       if (cpipe->next == NULL) {
+                               syntax_error("malformed for");
+                               debug_leave();
+                               debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
+                               return 1;
+                       }
+                       /* "FOR v; do ..." and "for v IN a b; do..." are ok */
+                       if (cpipe->next->res_word == RES_DO)
+                               continue;
+                       /* next word is not "do". It must be "in" then ("FOR v in ...") */
+                       if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
+                        || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
+                       ) {
+                               syntax_error("malformed for");
+                               debug_leave();
+                               debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
+                               return 1;
+                       }
+               }
+       }
+#endif
+
+       /* Past this point, all code paths should jump to ret: label
+        * in order to return, no direct "return" statements please.
+        * This helps to ensure that no memory is leaked. */
+
+#if ENABLE_HUSH_JOB
+       G.run_list_level++;
+#endif
+
+#if HAS_KEYWORDS
+       rword = RES_NONE;
+       last_rword = RES_XXXX;
+#endif
+       last_followup = PIPE_SEQ;
+       rcode = G.last_exitcode;
+
+       /* Go through list of pipes, (maybe) executing them. */
+       for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
+               int r;
+               int sv_errexit_depth;
+
+               if (G.flag_SIGINT)
+                       break;
+               if (G_flag_return_in_progress == 1)
+                       break;
+
+               IF_HAS_KEYWORDS(rword = pi->res_word;)
+               debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
+                               rword, cond_code, last_rword);
+
+               sv_errexit_depth = G.errexit_depth;
+               if (
+#if ENABLE_HUSH_IF
+                   rword == RES_IF || rword == RES_ELIF ||
+#endif
+                   pi->followup != PIPE_SEQ
+               ) {
+                       G.errexit_depth++;
+               }
+#if ENABLE_HUSH_LOOPS
+               if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
+                && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
+               ) {
+                       /* start of a loop: remember where loop starts */
+                       loop_top = pi;
+                       G.depth_of_loop++;
+               }
+#endif
+               /* Still in the same "if...", "then..." or "do..." branch? */
+               if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
+                       if ((rcode == 0 && last_followup == PIPE_OR)
+                        || (rcode != 0 && last_followup == PIPE_AND)
+                       ) {
+                               /* It is "<true> || CMD" or "<false> && CMD"
+                                * and we should not execute CMD */
+                               debug_printf_exec("skipped cmd because of || or &&\n");
+                               last_followup = pi->followup;
+                               goto dont_check_jobs_but_continue;
+                       }
+               }
+               last_followup = pi->followup;
+               IF_HAS_KEYWORDS(last_rword = rword;)
+#if ENABLE_HUSH_IF
+               if (cond_code) {
+                       if (rword == RES_THEN) {
+                               /* if false; then ... fi has exitcode 0! */
+                               G.last_exitcode = rcode = EXIT_SUCCESS;
+                               /* "if <false> THEN cmd": skip cmd */
+                               continue;
+                       }
+               } else {
+                       if (rword == RES_ELSE || rword == RES_ELIF) {
+                               /* "if <true> then ... ELSE/ELIF cmd":
+                                * skip cmd and all following ones */
+                               break;
+                       }
+               }
+#endif
+#if ENABLE_HUSH_LOOPS
+               if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
+                       if (!for_lcur) {
+                               /* first loop through for */
+
+                               static const char encoded_dollar_at[] ALIGN1 = {
+                                       SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
+                               }; /* encoded representation of "$@" */
+                               static const char *const encoded_dollar_at_argv[] = {
+                                       encoded_dollar_at, NULL
+                               }; /* argv list with one element: "$@" */
+                               char **vals;
+
+                               G.last_exitcode = rcode = EXIT_SUCCESS;
+                               vals = (char**)encoded_dollar_at_argv;
+                               if (pi->next->res_word == RES_IN) {
+                                       /* if no variable values after "in" we skip "for" */
+                                       if (!pi->next->cmds[0].argv) {
+                                               debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
+                                               break;
+                                       }
+                                       vals = pi->next->cmds[0].argv;
+                               } /* else: "for var; do..." -> assume "$@" list */
+                               /* create list of variable values */
+                               debug_print_strings("for_list made from", vals);
+                               for_list = expand_strvec_to_strvec(vals);
+                               for_lcur = for_list;
+                               debug_print_strings("for_list", for_list);
+                       }
+                       if (!*for_lcur) {
+                               /* "for" loop is over, clean up */
+                               free(for_list);
+                               for_list = NULL;
+                               for_lcur = NULL;
+                               break;
+                       }
+                       /* Insert next value from for_lcur */
+                       /* note: *for_lcur already has quotes removed, $var expanded, etc */
+                       set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0);
+                       continue;
+               }
+               if (rword == RES_IN) {
+                       continue; /* "for v IN list;..." - "in" has no cmds anyway */
+               }
+               if (rword == RES_DONE) {
+                       continue; /* "done" has no cmds too */
+               }
+#endif
+#if ENABLE_HUSH_CASE
+               if (rword == RES_CASE) {
+                       debug_printf_exec("CASE cond_code:%d\n", cond_code);
+                       case_word = expand_string_to_string(pi->cmds->argv[0],
+                               EXP_FLAG_ESC_GLOB_CHARS, /*unbackslash:*/ 1);
+                       debug_printf_exec("CASE word1:'%s'\n", case_word);
+                       //unbackslash(case_word);
+                       //debug_printf_exec("CASE word2:'%s'\n", case_word);
+                       continue;
+               }
+               if (rword == RES_MATCH) {
+                       char **argv;
+
+                       debug_printf_exec("MATCH cond_code:%d\n", cond_code);
+                       if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
+                               break;
+                       /* all prev words didn't match, does this one match? */
+                       argv = pi->cmds->argv;
+                       while (*argv) {
+                               char *pattern;
+                               debug_printf_exec("expand_string_to_string('%s')\n", *argv);
+                               pattern = expand_string_to_string(*argv,
+                                               EXP_FLAG_ESC_GLOB_CHARS,
+                                               /*unbackslash:*/ 0
+                               );
+                               /* TODO: which FNM_xxx flags to use? */
+                               cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
+                               debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n",
+                                               pattern, case_word, cond_code);
+                               free(pattern);
+                               if (cond_code == 0) {
+                                       /* match! we will execute this branch */
+                                       free(case_word);
+                                       case_word = NULL; /* make future "word)" stop */
+                                       break;
+                               }
+                               argv++;
+                       }
+                       continue;
+               }
+               if (rword == RES_CASE_BODY) { /* inside of a case branch */
+                       debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
+                       if (cond_code != 0)
+                               continue; /* not matched yet, skip this pipe */
+               }
+               if (rword == RES_ESAC) {
+                       debug_printf_exec("ESAC cond_code:%d\n", cond_code);
+                       if (case_word) {
+                               /* "case" did not match anything: still set $? (to 0) */
+                               G.last_exitcode = rcode = EXIT_SUCCESS;
+                       }
+               }
+#endif
+               /* Just pressing <enter> in shell should check for jobs.
+                * OTOH, in non-interactive shell this is useless
+                * and only leads to extra job checks */
+               if (pi->num_cmds == 0) {
+                       if (G_interactive_fd)
+                               goto check_jobs_and_continue;
+                       continue;
+               }
+
+               /* After analyzing all keywords and conditions, we decided
+                * to execute this pipe. NB: have to do checkjobs(NULL)
+                * after run_pipe to collect any background children,
+                * even if list execution is to be stopped. */
+               debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
+#if ENABLE_HUSH_LOOPS
+               G.flag_break_continue = 0;
+#endif
+               rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
+               if (r != -1) {
+                       /* We ran a builtin, function, or group.
+                        * rcode is already known
+                        * and we don't need to wait for anything. */
+                       debug_printf_exec(": builtin/func exitcode %d\n", rcode);
+                       G.last_exitcode = rcode;
+                       check_and_run_traps();
+#if ENABLE_HUSH_TRAP && ENABLE_HUSH_FUNCTIONS
+                       rcode = G.last_exitcode; /* "return" in trap can change it, read back */
+#endif
+#if ENABLE_HUSH_LOOPS
+                       /* Was it "break" or "continue"? */
+                       if (G.flag_break_continue) {
+                               smallint fbc = G.flag_break_continue;
+                               /* We might fall into outer *loop*,
+                                * don't want to break it too */
+                               if (loop_top) {
+                                       G.depth_break_continue--;
+                                       if (G.depth_break_continue == 0)
+                                               G.flag_break_continue = 0;
+                                       /* else: e.g. "continue 2" should *break* once, *then* continue */
+                               } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
+                               if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
+                                       checkjobs(NULL, 0 /*(no pid to wait for)*/);
+                                       break;
+                               }
+                               /* "continue": simulate end of loop */
+                               rword = RES_DONE;
+                               continue;
+                       }
+#endif
+                       if (G_flag_return_in_progress == 1) {
+                               checkjobs(NULL, 0 /*(no pid to wait for)*/);
+                               break;
+                       }
+               } else if (pi->followup == PIPE_BG) {
+                       /* What does bash do with attempts to background builtins? */
+                       /* even bash 3.2 doesn't do that well with nested bg:
+                        * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
+                        * I'm NOT treating inner &'s as jobs */
+#if ENABLE_HUSH_JOB
+                       if (G.run_list_level == 1)
+                               insert_job_into_table(pi);
+#endif
+                       /* Last command's pid goes to $! */
+                       G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
+                       G.last_bg_pid_exitcode = 0;
+                       debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
+/* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash say 0 */
+                       rcode = EXIT_SUCCESS;
+                       goto check_traps;
+               } else {
+#if ENABLE_HUSH_JOB
+                       if (G.run_list_level == 1 && G_interactive_fd) {
+                               /* Waits for completion, then fg's main shell */
+                               rcode = checkjobs_and_fg_shell(pi);
+                               debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
+                               goto check_traps;
+                       }
+#endif
+                       /* This one just waits for completion */
+                       rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
+                       debug_printf_exec(": checkjobs exitcode %d\n", rcode);
+ check_traps:
+                       G.last_exitcode = rcode;
+                       check_and_run_traps();
+#if ENABLE_HUSH_TRAP && ENABLE_HUSH_FUNCTIONS
+                       rcode = G.last_exitcode; /* "return" in trap can change it, read back */
+#endif
+               }
+
+               /* Handle "set -e" */
+               if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
+                       debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
+                       if (G.errexit_depth == 0)
+                               hush_exit(rcode);
+               }
+               G.errexit_depth = sv_errexit_depth;
+
+               /* Analyze how result affects subsequent commands */
+#if ENABLE_HUSH_IF
+               if (rword == RES_IF || rword == RES_ELIF)
+                       cond_code = rcode;
+#endif
+ check_jobs_and_continue:
+               checkjobs(NULL, 0 /*(no pid to wait for)*/);
+ dont_check_jobs_but_continue: ;
+#if ENABLE_HUSH_LOOPS
+               /* Beware of "while false; true; do ..."! */
+               if (pi->next
+                && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
+                /* check for RES_DONE is needed for "while ...; do \n done" case */
+               ) {
+                       if (rword == RES_WHILE) {
+                               if (rcode) {
+                                       /* "while false; do...done" - exitcode 0 */
+                                       G.last_exitcode = rcode = EXIT_SUCCESS;
+                                       debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
+                                       break;
+                               }
+                       }
+                       if (rword == RES_UNTIL) {
+                               if (!rcode) {
+                                       debug_printf_exec(": until expr is true: breaking\n");
+                                       break;
+                               }
+                       }
+               }
+#endif
+       } /* for (pi) */
+
+#if ENABLE_HUSH_JOB
+       G.run_list_level--;
+#endif
+#if ENABLE_HUSH_LOOPS
+       if (loop_top)
+               G.depth_of_loop--;
+       free(for_list);
+#endif
+#if ENABLE_HUSH_CASE
+       free(case_word);
+#endif
+       debug_leave();
+       debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
+       return rcode;
+}
+
+/* Select which version we will use */
+static int run_and_free_list(struct pipe *pi)
+{
+       int rcode = 0;
+       debug_printf_exec("run_and_free_list entered\n");
+       if (!G.o_opt[OPT_O_NOEXEC]) {
+               debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
+               rcode = run_list(pi);
+       }
+       /* free_pipe_list has the side effect of clearing memory.
+        * In the long run that function can be merged with run_list,
+        * but doing that now would hobble the debugging effort. */
+       free_pipe_list(pi);
+       debug_printf_exec("run_and_free_list return %d\n", rcode);
+       return rcode;
+}
+
+
+static void install_sighandlers(unsigned mask)
+{
+       sighandler_t old_handler;
+       unsigned sig = 0;
+       while ((mask >>= 1) != 0) {
+               sig++;
+               if (!(mask & 1))
+                       continue;
+               old_handler = install_sighandler(sig, pick_sighandler(sig));
+               /* POSIX allows shell to re-enable SIGCHLD
+                * even if it was SIG_IGN on entry.
+                * Therefore we skip IGN check for it:
+                */
+               if (sig == SIGCHLD)
+                       continue;
+               /* Interactive bash re-enables SIGHUP which is SIG_IGNed on entry.
+                * Try:
+                * trap '' hup; bash; echo RET  # type "kill -hup $$", see SIGHUP having effect
+                * trap '' hup; bash -c 'kill -hup $$; echo ALIVE'  # here SIGHUP is SIG_IGNed
+                */
+               if (sig == SIGHUP && G_interactive_fd)
+                       continue;
+               /* Unless one of the above signals, is it SIG_IGN? */
+               if (old_handler == SIG_IGN) {
+                       /* oops... restore back to IGN, and record this fact */
+                       install_sighandler(sig, old_handler);
+#if ENABLE_HUSH_TRAP
+                       if (!G_traps)
+                               G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
+                       free(G_traps[sig]);
+                       G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
+#endif
+               }
+       }
+}
+
+/* Called a few times only (or even once if "sh -c") */
+static void install_special_sighandlers(void)
+{
+       unsigned mask;
+
+       /* Which signals are shell-special? */
+       mask = (1 << SIGQUIT) | (1 << SIGCHLD);
+       if (G_interactive_fd) {
+               mask |= SPECIAL_INTERACTIVE_SIGS;
+               if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
+                       mask |= SPECIAL_JOBSTOP_SIGS;
+       }
+       /* Careful, do not re-install handlers we already installed */
+       if (G.special_sig_mask != mask) {
+               unsigned diff = mask & ~G.special_sig_mask;
+               G.special_sig_mask = mask;
+               install_sighandlers(diff);
+       }
+}
+
+#if ENABLE_HUSH_JOB
+/* helper */
+/* Set handlers to restore tty pgrp and exit */
+static void install_fatal_sighandlers(void)
+{
+       unsigned mask;
+
+       /* We will restore tty pgrp on these signals */
+       mask = 0
+               /*+ (1 << SIGILL ) * HUSH_DEBUG*/
+               /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
+               + (1 << SIGBUS ) * HUSH_DEBUG
+               + (1 << SIGSEGV) * HUSH_DEBUG
+               /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
+               + (1 << SIGABRT)
+       /* bash 3.2 seems to handle these just like 'fatal' ones */
+               + (1 << SIGPIPE)
+               + (1 << SIGALRM)
+       /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
+        * if we aren't interactive... but in this case
+        * we never want to restore pgrp on exit, and this fn is not called
+        */
+               /*+ (1 << SIGHUP )*/
+               /*+ (1 << SIGTERM)*/
+               /*+ (1 << SIGINT )*/
+       ;
+       G_fatal_sig_mask = mask;
+
+       install_sighandlers(mask);
+}
+#endif
+
+static int set_mode(int state, char mode, const char *o_opt)
+{
+       int idx;
+       switch (mode) {
+       case 'n':
+               G.o_opt[OPT_O_NOEXEC] = state;
+               break;
+       case 'x':
+               IF_HUSH_MODE_X(G_x_mode = state;)
+               IF_HUSH_MODE_X(if (G.x_mode_fd <= 0) G.x_mode_fd = dup_CLOEXEC(2, 10);)
+               break;
+       case 'e':
+               G.o_opt[OPT_O_ERREXIT] = state;
+               break;
+       case 'o':
+               if (!o_opt) {
+                       /* "set -o" or "set +o" without parameter.
+                        * in bash, set -o produces this output:
+                        *  pipefail        off
+                        * and set +o:
+                        *  set +o pipefail
+                        * We always use the second form.
+                        */
+                       const char *p = o_opt_strings;
+                       idx = 0;
+                       while (*p) {
+                               printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
+                               idx++;
+                               p += strlen(p) + 1;
+                       }
+                       break;
+               }
+               idx = index_in_strings(o_opt_strings, o_opt);
+               if (idx >= 0) {
+                       G.o_opt[idx] = state;
+                       break;
+               }
+               /* fall through to error */
+       default:
+               return EXIT_FAILURE;
+       }
+       return EXIT_SUCCESS;
+}
+
+int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int hush_main(int argc, char **argv)
+{
+       pid_t cached_getpid;
+       enum {
+               OPT_login = (1 << 0),
+       };
+       unsigned flags;
+#if !BB_MMU
+       unsigned builtin_argc = 0;
+#endif
+       char **e;
+       struct variable *cur_var;
+       struct variable *shell_ver;
+
+       INIT_G();
+       if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
+               G.last_exitcode = EXIT_SUCCESS;
+#if ENABLE_HUSH_TRAP
+# if ENABLE_HUSH_FUNCTIONS
+       G.return_exitcode = -1;
+# endif
+       G.pre_trap_exitcode = -1;
+#endif
+
+#if ENABLE_HUSH_FAST
+       G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
+#endif
+#if !BB_MMU
+       G.argv0_for_re_execing = argv[0];
+#endif
+
+       cached_getpid = getpid();   /* for tcsetpgrp() during init */
+       G.root_pid = cached_getpid; /* for $PID  (NOMMU can override via -$HEXPID:HEXPPID:...) */
+       G.root_ppid = getppid();    /* for $PPID (NOMMU can override)  */
+
+       /* Deal with HUSH_VERSION */
+       debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
+       unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
+       shell_ver = xzalloc(sizeof(*shell_ver));
+       shell_ver->flg_export = 1;
+       shell_ver->flg_read_only = 1;
+       /* Code which handles ${var<op>...} needs writable values for all variables,
+        * therefore we xstrdup: */
+       shell_ver->varstr = xstrdup(hush_version_str);
+
+       /* Create shell local variables from the values
+        * currently living in the environment */
+       G.top_var = shell_ver;
+       cur_var = G.top_var;
+       e = environ;
+       if (e) while (*e) {
+               char *value = strchr(*e, '=');
+               if (value) { /* paranoia */
+                       cur_var->next = xzalloc(sizeof(*cur_var));
+                       cur_var = cur_var->next;
+                       cur_var->varstr = *e;
+                       cur_var->max_len = strlen(*e);
+                       cur_var->flg_export = 1;
+               }
+               e++;
+       }
+       /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
+       debug_printf_env("putenv '%s'\n", shell_ver->varstr);
+       putenv(shell_ver->varstr);
+
+       /* Export PWD */
+       set_pwd_var(SETFLAG_EXPORT);
+
+#if BASH_HOSTNAME_VAR
+       /* Set (but not export) HOSTNAME unless already set */
+       if (!get_local_var_value("HOSTNAME")) {
+               struct utsname uts;
+               uname(&uts);
+               set_local_var_from_halves("HOSTNAME", uts.nodename);
+       }
+#endif
+       /* IFS is not inherited from the parent environment */
+       set_local_var_from_halves("IFS", defifs);
+
+       if (!get_local_var_value("PATH"))
+               set_local_var_from_halves("PATH", bb_default_root_path);
+
+       /* PS1/PS2 are set later, if we determine that we are interactive */
+
+       /* bash also exports SHLVL and _,
+        * and sets (but doesn't export) the following variables:
+        * BASH=/bin/bash
+        * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
+        * BASH_VERSION='3.2.0(1)-release'
+        * HOSTTYPE=i386
+        * MACHTYPE=i386-pc-linux-gnu
+        * OSTYPE=linux-gnu
+        * PPID=<NNNNN> - we also do it elsewhere
+        * EUID=<NNNNN>
+        * UID=<NNNNN>
+        * GROUPS=()
+        * LINES=<NNN>
+        * COLUMNS=<NNN>
+        * BASH_ARGC=()
+        * BASH_ARGV=()
+        * BASH_LINENO=()
+        * BASH_SOURCE=()
+        * DIRSTACK=()
+        * PIPESTATUS=([0]="0")
+        * HISTFILE=/<xxx>/.bash_history
+        * HISTFILESIZE=500
+        * HISTSIZE=500
+        * MAILCHECK=60
+        * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
+        * SHELL=/bin/bash
+        * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
+        * TERM=dumb
+        * OPTERR=1
+        * OPTIND=1
+        * PS4='+ '
+        */
+
+#if NUM_SCRIPTS > 0
+       if (argc < 0) {
+               char *script = get_script_content(-argc - 1);
+               G.global_argv = argv;
+               G.global_argc = string_array_len(argv);
+               //install_special_sighandlers(); - needed?
+               parse_and_run_string(script);
+               goto final_return;
+       }
+#endif
+
+       /* Initialize some more globals to non-zero values */
+       die_func = restore_ttypgrp_and__exit;
+
+       /* Shell is non-interactive at first. We need to call
+        * install_special_sighandlers() if we are going to execute "sh <script>",
+        * "sh -c <cmds>" or login shell's /etc/profile and friends.
+        * If we later decide that we are interactive, we run install_special_sighandlers()
+        * in order to intercept (more) signals.
+        */
+
+       /* Parse options */
+       /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
+       flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
+       while (1) {
+               int opt = getopt(argc, argv, "+" /* stop at 1st non-option */
+                               "cexinsl"
+#if !BB_MMU
+                               "<:$:R:V:"
+# if ENABLE_HUSH_FUNCTIONS
+                               "F:"
+# endif
+#endif
+               );
+               if (opt <= 0)
+                       break;
+               switch (opt) {
+               case 'c':
+                       /* Note: -c is not an option with param!
+                        * "hush -c -l SCRIPT" is valid. "hush -cSCRIPT" is not.
+                        */
+                       G.opt_c = 1;
+                       break;
+               case 'i':
+                       /* Well, we cannot just declare interactiveness,
+                        * we have to have some stuff (ctty, etc) */
+                       /* G_interactive_fd++; */
+                       break;
+               case 's':
+                       G.opt_s = 1;
+                       break;
+               case 'l':
+                       flags |= OPT_login;
+                       break;
+#if !BB_MMU
+               case '<': /* "big heredoc" support */
+                       full_write1_str(optarg);
+                       _exit(0);
+               case '$': {
+                       unsigned long long empty_trap_mask;
+
+                       G.root_pid = bb_strtou(optarg, &optarg, 16);
+                       optarg++;
+                       G.root_ppid = bb_strtou(optarg, &optarg, 16);
+                       optarg++;
+                       G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
+                       optarg++;
+                       G.last_exitcode = bb_strtou(optarg, &optarg, 16);
+                       optarg++;
+                       builtin_argc = bb_strtou(optarg, &optarg, 16);
+                       optarg++;
+                       empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
+                       if (empty_trap_mask != 0) {
+                               IF_HUSH_TRAP(int sig;)
+                               install_special_sighandlers();
+# if ENABLE_HUSH_TRAP
+                               G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
+                               for (sig = 1; sig < NSIG; sig++) {
+                                       if (empty_trap_mask & (1LL << sig)) {
+                                               G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
+                                               install_sighandler(sig, SIG_IGN);
+                                       }
+                               }
+# endif
+                       }
+# if ENABLE_HUSH_LOOPS
+                       optarg++;
+                       G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
+# endif
+                       /* Suppress "killed by signal" message, -$ hack is used
+                        * for subshells: echo `sh -c 'kill -9 $$'`
+                        * should be silent.
+                        */
+                       IF_HUSH_JOB(G.run_list_level = 1;)
+# if ENABLE_HUSH_FUNCTIONS
+                       /* nommu uses re-exec trick for "... | func | ...",
+                        * should allow "return".
+                        * This accidentally allows returns in subshells.
+                        */
+                       G_flag_return_in_progress = -1;
+# endif
+                       break;
+               }
+               case 'R':
+               case 'V':
+                       set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0);
+                       break;
+# if ENABLE_HUSH_FUNCTIONS
+               case 'F': {
+                       struct function *funcp = new_function(optarg);
+                       /* funcp->name is already set to optarg */
+                       /* funcp->body is set to NULL. It's a special case. */
+                       funcp->body_as_string = argv[optind];
+                       optind++;
+                       break;
+               }
+# endif
+#endif
+               /*case '?': invalid option encountered (set_mode('?') will fail) */
+               /*case 'n':*/
+               /*case 'x':*/
+               /*case 'e':*/
+               default:
+                       if (set_mode(1, opt, NULL) == 0) /* no error */
+                               break;
+                       bb_show_usage();
+               }
+       } /* option parsing loop */
+
+       /* Skip options. Try "hush -l": $1 should not be "-l"! */
+       G.global_argc = argc - (optind - 1);
+       G.global_argv = argv + (optind - 1);
+       G.global_argv[0] = argv[0];
+
+       /* If we are login shell... */
+       if (flags & OPT_login) {
+               const char *hp = NULL;
+               HFILE *input;
+
+               debug_printf("sourcing /etc/profile\n");
+               input = hfopen("/etc/profile");
+ run_profile:
+               if (input != NULL) {
+                       install_special_sighandlers();
+                       parse_and_run_file(input);
+                       hfclose(input);
+               }
+               /* bash: after sourcing /etc/profile,
+                * tries to source (in the given order):
+                * ~/.bash_profile, ~/.bash_login, ~/.profile,
+                * stopping on first found. --noprofile turns this off.
+                * bash also sources ~/.bash_logout on exit.
+                * If called as sh, skips .bash_XXX files.
+                */
+               if (!hp) { /* unless we looped on the "goto" already */
+                       hp = get_local_var_value("HOME");
+                       if (hp && hp[0]) {
+                               debug_printf("sourcing ~/.profile\n");
+                               hp = concat_path_file(hp, ".profile");
+                               input = hfopen(hp);
+                               free((char*)hp);
+                               goto run_profile;
+                       }
+               }
+       }
+
+       /* -c takes effect *after* -l */
+       if (G.opt_c) {
+               /* Possibilities:
+                * sh ... -c 'script'
+                * sh ... -c 'script' ARG0 [ARG1...]
+                * On NOMMU, if builtin_argc != 0,
+                * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
+                * "" needs to be replaced with NULL
+                * and BARGV vector fed to builtin function.
+                * Note: the form without ARG0 never happens:
+                * sh ... -c 'builtin' BARGV... ""
+                */
+               char *script;
+
+               install_special_sighandlers();
+
+               G.global_argc--;
+               G.global_argv++;
+#if !BB_MMU
+               if (builtin_argc) {
+                       /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
+                       const struct built_in_command *x;
+                       x = find_builtin(G.global_argv[0]);
+                       if (x) { /* paranoia */
+                               argv = G.global_argv;
+                               G.global_argc -= builtin_argc + 1; /* skip [BARGV...] "" */
+                               G.global_argv += builtin_argc + 1;
+                               G.global_argv[-1] = NULL; /* replace "" */
+                               G.last_exitcode = x->b_function(argv);
+                       }
+                       goto final_return;
+               }
+#endif
+
+               script = G.global_argv[0];
+               if (!script)
+                       bb_error_msg_and_die(bb_msg_requires_arg, "-c");
+               if (!G.global_argv[1]) {
+                       /* -c 'script' (no params): prevent empty $0 */
+                       G.global_argv[0] = argv[0];
+               } else { /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
+                       G.global_argc--;
+                       G.global_argv++;
+               }
+               parse_and_run_string(script);
+               goto final_return;
+       }
+
+       /* -s is: hush -s ARGV1 ARGV2 (no SCRIPT) */
+       if (!G.opt_s && G.global_argv[1]) {
+               HFILE *input;
+               /*
+                * "bash <script>" (which is never interactive (unless -i?))
+                * sources $BASH_ENV here (without scanning $PATH).
+                * If called as sh, does the same but with $ENV.
+                * Also NB, per POSIX, $ENV should undergo parameter expansion.
+                */
+               G.global_argc--;
+               G.global_argv++;
+               debug_printf("running script '%s'\n", G.global_argv[0]);
+               xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
+               input = hfopen(G.global_argv[0]);
+               if (!input) {
+                       bb_simple_perror_msg_and_die(G.global_argv[0]);
+               }
+               xfunc_error_retval = 1;
+               install_special_sighandlers();
+               parse_and_run_file(input);
+#if ENABLE_FEATURE_CLEAN_UP
+               hfclose(input);
+#endif
+               goto final_return;
+       }
+       /* "implicit" -s: bare interactive hush shows 's' in $- */
+       G.opt_s = 1;
+
+       /* Up to here, shell was non-interactive. Now it may become one.
+        * NB: don't forget to (re)run install_special_sighandlers() as needed.
+        */
+
+       /* A shell is interactive if the '-i' flag was given,
+        * or if all of the following conditions are met:
+        *    no -c command
+        *    no arguments remaining or the -s flag given
+        *    standard input is a terminal
+        *    standard output is a terminal
+        * Refer to Posix.2, the description of the 'sh' utility.
+        */
+#if ENABLE_HUSH_JOB
+       if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
+               G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
+               debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
+               if (G_saved_tty_pgrp < 0)
+                       G_saved_tty_pgrp = 0;
+
+               /* try to dup stdin to high fd#, >= 255 */
+               G_interactive_fd = dup_CLOEXEC(STDIN_FILENO, 254);
+               if (G_interactive_fd < 0) {
+                       /* try to dup to any fd */
+                       G_interactive_fd = dup(STDIN_FILENO);
+                       if (G_interactive_fd < 0) {
+                               /* give up */
+                               G_interactive_fd = 0;
+                               G_saved_tty_pgrp = 0;
+                       }
+               }
+       }
+       debug_printf("interactive_fd:%d\n", G_interactive_fd);
+       if (G_interactive_fd) {
+               close_on_exec_on(G_interactive_fd);
+
+               if (G_saved_tty_pgrp) {
+                       /* If we were run as 'hush &', sleep until we are
+                        * in the foreground (tty pgrp == our pgrp).
+                        * If we get started under a job aware app (like bash),
+                        * make sure we are now in charge so we don't fight over
+                        * who gets the foreground */
+                       while (1) {
+                               pid_t shell_pgrp = getpgrp();
+                               G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
+                               if (G_saved_tty_pgrp == shell_pgrp)
+                                       break;
+                               /* send TTIN to ourself (should stop us) */
+                               kill(- shell_pgrp, SIGTTIN);
+                       }
+               }
+
+               /* Install more signal handlers */
+               install_special_sighandlers();
+
+               if (G_saved_tty_pgrp) {
+                       /* Set other signals to restore saved_tty_pgrp */
+                       install_fatal_sighandlers();
+                       /* Put ourselves in our own process group
+                        * (bash, too, does this only if ctty is available) */
+                       bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
+                       /* Grab control of the terminal */
+                       tcsetpgrp(G_interactive_fd, cached_getpid);
+               }
+               enable_restore_tty_pgrp_on_exit();
+
+# if ENABLE_FEATURE_EDITING
+               G.line_input_state = new_line_input_t(FOR_SHELL);
+#  if EDITING_HAS_get_exe_name
+               G.line_input_state->get_exe_name = get_builtin_name;
+#  endif
+# endif
+# if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
+               {
+                       const char *hp = get_local_var_value("HISTFILE");
+                       if (!hp) {
+                               hp = get_local_var_value("HOME");
+                               if (hp)
+                                       hp = concat_path_file(hp, ".hush_history");
+                       } else {
+                               hp = xstrdup(hp);
+                       }
+                       if (hp) {
+                               G.line_input_state->hist_file = hp;
+                               //set_local_var(xasprintf("HISTFILE=%s", ...));
+                       }
+#  if ENABLE_FEATURE_SH_HISTFILESIZE
+                       hp = get_local_var_value("HISTFILESIZE");
+                       G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
+#  endif
+               }
+# endif
+       } else {
+               install_special_sighandlers();
+       }
+#elif ENABLE_HUSH_INTERACTIVE
+       /* No job control compiled in, only prompt/line editing */
+       if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
+               G_interactive_fd = dup_CLOEXEC(STDIN_FILENO, 254);
+               if (G_interactive_fd < 0) {
+                       /* try to dup to any fd */
+                       G_interactive_fd = dup_CLOEXEC(STDIN_FILENO, -1);
+                       if (G_interactive_fd < 0)
+                               /* give up */
+                               G_interactive_fd = 0;
+               }
+       }
+       if (G_interactive_fd) {
+               close_on_exec_on(G_interactive_fd);
+       }
+       install_special_sighandlers();
+#else
+       /* We have interactiveness code disabled */
+       install_special_sighandlers();
+#endif
+       /* bash:
+        * if interactive but not a login shell, sources ~/.bashrc
+        * (--norc turns this off, --rcfile <file> overrides)
+        */
+
+       if (G_interactive_fd) {
+#if ENABLE_HUSH_INTERACTIVE && ENABLE_FEATURE_EDITING_FANCY_PROMPT
+               /* Set (but not export) PS1/2 unless already set */
+               if (!get_local_var_value("PS1"))
+                       set_local_var_from_halves("PS1", "\\w \\$ ");
+               if (!get_local_var_value("PS2"))
+                       set_local_var_from_halves("PS2", "> ");
+#endif
+               if (!ENABLE_FEATURE_SH_EXTRA_QUIET) {
+                       /* note: ash and hush share this string */
+                       printf("\n\n%s %s\n"
+                               IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
+                               "\n",
+                               bb_banner,
+                               "hush - the humble shell"
+                       );
+               }
+       }
+
+       parse_and_run_file(hfopen(NULL)); /* stdin */
+
+ final_return:
+       hush_exit(G.last_exitcode);
+}
+
+
+/*
+ * Built-ins
+ */
+static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
+{
+       return 0;
+}
+
+#if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
+static NOINLINE int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
+{
+       int argc = string_array_len(argv);
+       return applet_main_func(argc, argv);
+}
+#endif
+#if ENABLE_HUSH_TEST || BASH_TEST2
+static int FAST_FUNC builtin_test(char **argv)
+{
+       return run_applet_main(argv, test_main);
+}
+#endif
+#if ENABLE_HUSH_ECHO
+static int FAST_FUNC builtin_echo(char **argv)
+{
+       return run_applet_main(argv, echo_main);
+}
+#endif
+#if ENABLE_HUSH_PRINTF
+static int FAST_FUNC builtin_printf(char **argv)
+{
+       return run_applet_main(argv, printf_main);
+}
+#endif
+
+#if ENABLE_HUSH_HELP
+static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
+{
+       const struct built_in_command *x;
+
+       printf(
+               "Built-in commands:\n"
+               "------------------\n");
+       for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
+               if (x->b_descr)
+                       printf("%-10s%s\n", x->b_cmd, x->b_descr);
+       }
+       return EXIT_SUCCESS;
+}
+#endif
+
+#if MAX_HISTORY && ENABLE_FEATURE_EDITING
+static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
+{
+       show_history(G.line_input_state);
+       return EXIT_SUCCESS;
+}
+#endif
+
+static char **skip_dash_dash(char **argv)
+{
+       argv++;
+       if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
+               argv++;
+       return argv;
+}
+
+static int FAST_FUNC builtin_cd(char **argv)
+{
+       const char *newdir;
+
+       argv = skip_dash_dash(argv);
+       newdir = argv[0];
+       if (newdir == NULL) {
+               /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
+                * bash says "bash: cd: HOME not set" and does nothing
+                * (exitcode 1)
+                */
+               const char *home = get_local_var_value("HOME");
+               newdir = home ? home : "/";
+       }
+       if (chdir(newdir)) {
+               /* Mimic bash message exactly */
+               bb_perror_msg("cd: %s", newdir);
+               return EXIT_FAILURE;
+       }
+       /* Read current dir (get_cwd(1) is inside) and set PWD.
+        * Note: do not enforce exporting. If PWD was unset or unexported,
+        * set it again, but do not export. bash does the same.
+        */
+       set_pwd_var(/*flag:*/ 0);
+       return EXIT_SUCCESS;
+}
+
+static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
+{
+       puts(get_cwd(0));
+       return EXIT_SUCCESS;
+}
+
+static int FAST_FUNC builtin_eval(char **argv)
+{
+       argv = skip_dash_dash(argv);
+
+       if (!argv[0])
+               return EXIT_SUCCESS;
+
+       IF_HUSH_MODE_X(G.x_mode_depth++;)
+       //bb_error_msg("%s: ++x_mode_depth=%d", __func__, G.x_mode_depth);
+       if (!argv[1]) {
+               /* bash:
+                * eval "echo Hi; done" ("done" is syntax error):
+                * "echo Hi" will not execute too.
+                */
+               parse_and_run_string(argv[0]);
+       } else {
+               /* "The eval utility shall construct a command by
+                * concatenating arguments together, separating
+                * each with a <space> character."
+                */
+               char *str, *p;
+               unsigned len = 0;
+               char **pp = argv;
+               do
+                       len += strlen(*pp) + 1;
+               while (*++pp);
+               str = p = xmalloc(len);
+               pp = argv;
+               for (;;) {
+                       p = stpcpy(p, *pp);
+                       pp++;
+                       if (!*pp)
+                               break;
+                       *p++ = ' ';
+               }
+               parse_and_run_string(str);
+               free(str);
+       }
+       IF_HUSH_MODE_X(G.x_mode_depth--;)
+       //bb_error_msg("%s: --x_mode_depth=%d", __func__, G.x_mode_depth);
+       return G.last_exitcode;
+}
+
+static int FAST_FUNC builtin_exec(char **argv)
+{
+       argv = skip_dash_dash(argv);
+       if (argv[0] == NULL)
+               return EXIT_SUCCESS; /* bash does this */
+
+       /* Careful: we can end up here after [v]fork. Do not restore
+        * tty pgrp then, only top-level shell process does that */
+       if (G_saved_tty_pgrp && getpid() == G.root_pid)
+               tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
+
+       /* Saved-redirect fds, script fds and G_interactive_fd are still
+        * open here. However, they are all CLOEXEC, and execv below
+        * closes them. Try interactive "exec ls -l /proc/self/fd",
+        * it should show no extra open fds in the "ls" process.
+        * If we'd try to run builtins/NOEXECs, this would need improving.
+        */
+       //close_saved_fds_and_FILE_fds();
+
+       /* TODO: if exec fails, bash does NOT exit! We do.
+        * We'll need to undo trap cleanup (it's inside execvp_or_die)
+        * and tcsetpgrp, and this is inherently racy.
+        */
+       execvp_or_die(argv);
+}
+
+static int FAST_FUNC builtin_exit(char **argv)
+{
+       debug_printf_exec("%s()\n", __func__);
+
+       /* interactive bash:
+        * # trap "echo EEE" EXIT
+        * # exit
+        * exit
+        * There are stopped jobs.
+        * (if there are _stopped_ jobs, running ones don't count)
+        * # exit
+        * exit
+        * EEE (then bash exits)
+        *
+        * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
+        */
+
+       /* note: EXIT trap is run by hush_exit */
+       argv = skip_dash_dash(argv);
+       if (argv[0] == NULL) {
+#if ENABLE_HUSH_TRAP
+               if (G.pre_trap_exitcode >= 0) /* "exit" in trap uses $? from before the trap */
+                       hush_exit(G.pre_trap_exitcode);
+#endif
+               hush_exit(G.last_exitcode);
+       }
+       /* mimic bash: exit 123abc == exit 255 + error msg */
+       xfunc_error_retval = 255;
+       /* bash: exit -2 == exit 254, no error msg */
+       hush_exit(xatoi(argv[0]) & 0xff);
+}
+
+#if ENABLE_HUSH_TYPE
+/* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
+static int FAST_FUNC builtin_type(char **argv)
+{
+       int ret = EXIT_SUCCESS;
+
+       while (*++argv) {
+               const char *type;
+               char *path = NULL;
+
+               if (0) {} /* make conditional compile easier below */
+               /*else if (find_alias(*argv))
+                       type = "an alias";*/
+# if ENABLE_HUSH_FUNCTIONS
+               else if (find_function(*argv))
+                       type = "a function";
+# endif
+               else if (find_builtin(*argv))
+                       type = "a shell builtin";
+               else if ((path = find_in_path(*argv)) != NULL)
+                       type = path;
+               else {
+                       bb_error_msg("type: %s: not found", *argv);
+                       ret = EXIT_FAILURE;
+                       continue;
+               }
+
+               printf("%s is %s\n", *argv, type);
+               free(path);
+       }
+
+       return ret;
+}
+#endif
+
+#if ENABLE_HUSH_READ
+/* Interruptibility of read builtin in bash
+ * (tested on bash-4.2.8 by sending signals (not by ^C)):
+ *
+ * Empty trap makes read ignore corresponding signal, for any signal.
+ *
+ * SIGINT:
+ * - terminates non-interactive shell;
+ * - interrupts read in interactive shell;
+ * if it has non-empty trap:
+ * - executes trap and returns to command prompt in interactive shell;
+ * - executes trap and returns to read in non-interactive shell;
+ * SIGTERM:
+ * - is ignored (does not interrupt) read in interactive shell;
+ * - terminates non-interactive shell;
+ * if it has non-empty trap:
+ * - executes trap and returns to read;
+ * SIGHUP:
+ * - terminates shell (regardless of interactivity);
+ * if it has non-empty trap:
+ * - executes trap and returns to read;
+ * SIGCHLD from children:
+ * - does not interrupt read regardless of interactivity:
+ *   try: sleep 1 & read x; echo $x
+ */
+static int FAST_FUNC builtin_read(char **argv)
+{
+       const char *r;
+       struct builtin_read_params params;
+
+       memset(&params, 0, sizeof(params));
+
+       /* "!": do not abort on errors.
+        * Option string must start with "sr" to match BUILTIN_READ_xxx
+        */
+       params.read_flags = getopt32(argv,
+# if BASH_READ_D
+               IF_NOT_HUSH_BASH_COMPAT("^")
+               "!srn:p:t:u:d:" IF_NOT_HUSH_BASH_COMPAT("\0" "-1"/*min 1 arg*/),
+               &params.opt_n, &params.opt_p, &params.opt_t, &params.opt_u, &params.opt_d
+# else
+               IF_NOT_HUSH_BASH_COMPAT("^")
+               "!srn:p:t:u:" IF_NOT_HUSH_BASH_COMPAT("\0" "-1"/*min 1 arg*/),
+               &params.opt_n, &params.opt_p, &params.opt_t, &params.opt_u
+# endif
+//TODO: print "read: need variable name"
+//for the case of !BASH "read" with no args (now it fails silently)
+//(or maybe extend getopt32() to emit a message if "-1" fails)
+       );
+       if ((uint32_t)params.read_flags == (uint32_t)-1)
+               return EXIT_FAILURE;
+       argv += optind;
+       params.argv = argv;
+       params.setvar = set_local_var_from_halves;
+       params.ifs = get_local_var_value("IFS"); /* can be NULL */
+
+ again:
+       r = shell_builtin_read(&params);
+
+       if ((uintptr_t)r == 1 && errno == EINTR) {
+               unsigned sig = check_and_run_traps();
+               if (sig != SIGINT)
+                       goto again;
+       }
+
+       if ((uintptr_t)r > 1) {
+               bb_simple_error_msg(r);
+               r = (char*)(uintptr_t)1;
+       }
+
+       return (uintptr_t)r;
+}
+#endif
+
+#if ENABLE_HUSH_UMASK
+static int FAST_FUNC builtin_umask(char **argv)
+{
+       int rc;
+       mode_t mask;
+
+       rc = 1;
+       mask = umask(0);
+       argv = skip_dash_dash(argv);
+       if (argv[0]) {
+               mode_t old_mask = mask;
+
+               /* numeric umasks are taken as-is */
+               /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
+               if (!isdigit(argv[0][0]))
+                       mask ^= 0777;
+               mask = bb_parse_mode(argv[0], mask);
+               if (!isdigit(argv[0][0]))
+                       mask ^= 0777;
+               if ((unsigned)mask > 0777) {
+                       mask = old_mask;
+                       /* bash messages:
+                        * bash: umask: 'q': invalid symbolic mode operator
+                        * bash: umask: 999: octal number out of range
+                        */
+                       bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
+                       rc = 0;
+               }
+       } else {
+               /* Mimic bash */
+               printf("%04o\n", (unsigned) mask);
+               /* fall through and restore mask which we set to 0 */
+       }
+       umask(mask);
+
+       return !rc; /* rc != 0 - success */
+}
+#endif
+
+#if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
+static void print_escaped(const char *s)
+{
+       if (*s == '\'')
+               goto squote;
+       do {
+               const char *p = strchrnul(s, '\'');
+               /* print 'xxxx', possibly just '' */
+               printf("'%.*s'", (int)(p - s), s);
+               if (*p == '\0')
+                       break;
+               s = p;
+ squote:
+               /* s points to '; print "'''...'''" */
+               putchar('"');
+               do putchar('\''); while (*++s == '\'');
+               putchar('"');
+       } while (*s);
+}
+#endif
+
+#if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY
+static int helper_export_local(char **argv, unsigned flags)
+{
+       do {
+               char *name = *argv;
+               const char *name_end = endofname(name);
+
+               if (*name_end == '\0') {
+                       struct variable *var, **vpp;
+
+                       vpp = get_ptr_to_local_var(name, name_end - name);
+                       var = vpp ? *vpp : NULL;
+
+                       if (flags & SETFLAG_UNEXPORT) {
+                               /* export -n NAME (without =VALUE) */
+                               if (var) {
+                                       var->flg_export = 0;
+                                       debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
+                                       unsetenv(name);
+                               } /* else: export -n NOT_EXISTING_VAR: no-op */
+                               continue;
+                       }
+                       if (flags & SETFLAG_EXPORT) {
+                               /* export NAME (without =VALUE) */
+                               if (var) {
+                                       var->flg_export = 1;
+                                       debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
+                                       putenv(var->varstr);
+                                       continue;
+                               }
+                       }
+                       if (flags & SETFLAG_MAKE_RO) {
+                               /* readonly NAME (without =VALUE) */
+                               if (var) {
+                                       var->flg_read_only = 1;
+                                       continue;
+                               }
+                       }
+# if ENABLE_HUSH_LOCAL
+                       /* Is this "local" bltin? */
+                       if (!(flags & (SETFLAG_EXPORT|SETFLAG_UNEXPORT|SETFLAG_MAKE_RO))) {
+                               unsigned lvl = flags >> SETFLAG_VARLVL_SHIFT;
+                               if (var && var->var_nest_level == lvl) {
+                                       /* "local x=abc; ...; local x" - ignore second local decl */
+                                       continue;
+                               }
+                       }
+# endif
+                       /* Exporting non-existing variable.
+                        * bash does not put it in environment,
+                        * but remembers that it is exported,
+                        * and does put it in env when it is set later.
+                        * We just set it to "" and export.
+                        */
+                       /* Or, it's "local NAME" (without =VALUE).
+                        * bash sets the value to "".
+                        */
+                       /* Or, it's "readonly NAME" (without =VALUE).
+                        * bash remembers NAME and disallows its creation
+                        * in the future.
+                        */
+                       name = xasprintf("%s=", name);
+               } else {
+                       if (*name_end != '=') {
+                               bb_error_msg("'%s': bad variable name", name);
+                               /* do not parse following argv[]s: */
+                               return 1;
+                       }
+                       /* (Un)exporting/making local NAME=VALUE */
+                       name = xstrdup(name);
+                       /* Testcase: export PS1='\w \$ ' */
+                       unbackslash(name);
+               }
+               debug_printf_env("%s: set_local_var('%s')\n", __func__, name);
+               if (set_local_var(name, flags))
+                       return EXIT_FAILURE;
+       } while (*++argv);
+       return EXIT_SUCCESS;
+}
+#endif
+
+#if ENABLE_HUSH_EXPORT
+static int FAST_FUNC builtin_export(char **argv)
+{
+       unsigned opt_unexport;
+
+# if ENABLE_HUSH_EXPORT_N
+       /* "!": do not abort on errors */
+       opt_unexport = getopt32(argv, "!n");
+       if (opt_unexport == (uint32_t)-1)
+               return EXIT_FAILURE;
+       argv += optind;
+# else
+       opt_unexport = 0;
+       argv++;
+# endif
+
+       if (argv[0] == NULL) {
+               char **e = environ;
+               if (e) {
+                       while (*e) {
+# if 0
+                               puts(*e++);
+# else
+                               /* ash emits: export VAR='VAL'
+                                * bash: declare -x VAR="VAL"
+                                * we follow ash example */
+                               const char *s = *e++;
+                               const char *p = strchr(s, '=');
+
+                               if (!p) /* wtf? take next variable */
+                                       continue;
+                               /* export var= */
+                               printf("export %.*s", (int)(p - s) + 1, s);
+                               print_escaped(p + 1);
+                               putchar('\n');
+# endif
+                       }
+                       /*fflush_all(); - done after each builtin anyway */
+               }
+               return EXIT_SUCCESS;
+       }
+
+       return helper_export_local(argv, opt_unexport ? SETFLAG_UNEXPORT : SETFLAG_EXPORT);
+}
+#endif
+
+#if ENABLE_HUSH_LOCAL
+static int FAST_FUNC builtin_local(char **argv)
+{
+       if (G.func_nest_level == 0) {
+               bb_error_msg("%s: not in a function", argv[0]);
+               return EXIT_FAILURE; /* bash compat */
+       }
+       argv++;
+       /* Since all builtins run in a nested variable level,
+        * need to use level - 1 here. Or else the variable will be removed at once
+        * after builtin returns.
+        */
+       return helper_export_local(argv, (G.var_nest_level - 1) << SETFLAG_VARLVL_SHIFT);
+}
+#endif
+
+#if ENABLE_HUSH_READONLY
+static int FAST_FUNC builtin_readonly(char **argv)
+{
+       argv++;
+       if (*argv == NULL) {
+               /* bash: readonly [-p]: list all readonly VARs
+                * (-p has no effect in bash)
+                */
+               struct variable *e;
+               for (e = G.top_var; e; e = e->next) {
+                       if (e->flg_read_only) {
+//TODO: quote value: readonly VAR='VAL'
+                               printf("readonly %s\n", e->varstr);
+                       }
+               }
+               return EXIT_SUCCESS;
+       }
+       return helper_export_local(argv, SETFLAG_MAKE_RO);
+}
+#endif
+
+#if ENABLE_HUSH_UNSET
+/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
+static int FAST_FUNC builtin_unset(char **argv)
+{
+       int ret;
+       unsigned opts;
+
+       /* "!": do not abort on errors */
+       /* "+": stop at 1st non-option */
+       opts = getopt32(argv, "!+vf");
+       if (opts == (unsigned)-1)
+               return EXIT_FAILURE;
+       if (opts == 3) {
+               bb_simple_error_msg("unset: -v and -f are exclusive");
+               return EXIT_FAILURE;
+       }
+       argv += optind;
+
+       ret = EXIT_SUCCESS;
+       while (*argv) {
+               if (!(opts & 2)) { /* not -f */
+                       if (unset_local_var(*argv)) {
+                               /* unset <nonexistent_var> doesn't fail.
+                                * Error is when one tries to unset RO var.
+                                * Message was printed by unset_local_var. */
+                               ret = EXIT_FAILURE;
+                       }
+               }
+# if ENABLE_HUSH_FUNCTIONS
+               else {
+                       unset_func(*argv);
+               }
+# endif
+               argv++;
+       }
+       return ret;
+}
+#endif
+
+#if ENABLE_HUSH_SET
+/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
+ * built-in 'set' handler
+ * SUSv3 says:
+ * set [-abCefhmnuvx] [-o option] [argument...]
+ * set [+abCefhmnuvx] [+o option] [argument...]
+ * set -- [argument...]
+ * set -o
+ * set +o
+ * Implementations shall support the options in both their hyphen and
+ * plus-sign forms. These options can also be specified as options to sh.
+ * Examples:
+ * Write out all variables and their values: set
+ * Set $1, $2, and $3 and set "$#" to 3: set c a b
+ * Turn on the -x and -v options: set -xv
+ * Unset all positional parameters: set --
+ * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
+ * Set the positional parameters to the expansion of x, even if x expands
+ * with a leading '-' or '+': set -- $x
+ *
+ * So far, we only support "set -- [argument...]" and some of the short names.
+ */
+static int FAST_FUNC builtin_set(char **argv)
+{
+       int n;
+       char **pp, **g_argv;
+       char *arg = *++argv;
+
+       if (arg == NULL) {
+               struct variable *e;
+               for (e = G.top_var; e; e = e->next)
+                       puts(e->varstr);
+               return EXIT_SUCCESS;
+       }
+
+       do {
+               if (strcmp(arg, "--") == 0) {
+                       ++argv;
+                       goto set_argv;
+               }
+               if (arg[0] != '+' && arg[0] != '-')
+                       break;
+               for (n = 1; arg[n]; ++n) {
+                       if (set_mode((arg[0] == '-'), arg[n], argv[1])) {
+                               bb_error_msg("%s: %s: invalid option", "set", arg);
+                               return EXIT_FAILURE;
+                       }
+                       if (arg[n] == 'o' && argv[1])
+                               argv++;
+               }
+       } while ((arg = *++argv) != NULL);
+       /* Now argv[0] is 1st argument */
+
+       if (arg == NULL)
+               return EXIT_SUCCESS;
+ set_argv:
+
+       /* NB: G.global_argv[0] ($0) is never freed/changed */
+       g_argv = G.global_argv;
+       if (G.global_args_malloced) {
+               pp = g_argv;
+               while (*++pp)
+                       free(*pp);
+               g_argv[1] = NULL;
+       } else {
+               G.global_args_malloced = 1;
+               pp = xzalloc(sizeof(pp[0]) * 2);
+               pp[0] = g_argv[0]; /* retain $0 */
+               g_argv = pp;
+       }
+       /* This realloc's G.global_argv */
+       G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
+
+       G.global_argc = 1 + string_array_len(pp + 1);
+
+       return EXIT_SUCCESS;
+}
+#endif
+
+static int FAST_FUNC builtin_shift(char **argv)
+{
+       int n = 1;
+       argv = skip_dash_dash(argv);
+       if (argv[0]) {
+               n = bb_strtou(argv[0], NULL, 10);
+               if (errno || n < 0) {
+                       /* shared string with ash.c */
+                       bb_error_msg("Illegal number: %s", argv[0]);
+                       /*
+                        * ash aborts in this case.
+                        * bash prints error message and set $? to 1.
+                        * Interestingly, for "shift 99999" bash does not
+                        * print error message, but does set $? to 1
+                        * (and does no shifting at all).
+                        */
+               }
+       }
+       if (n >= 0 && n < G.global_argc) {
+               if (G_global_args_malloced) {
+                       int m = 1;
+                       while (m <= n)
+                               free(G.global_argv[m++]);
+               }
+               G.global_argc -= n;
+               memmove(&G.global_argv[1], &G.global_argv[n+1],
+                               G.global_argc * sizeof(G.global_argv[0]));
+               return EXIT_SUCCESS;
+       }
+       return EXIT_FAILURE;
+}
+
+#if ENABLE_HUSH_GETOPTS
+static int FAST_FUNC builtin_getopts(char **argv)
+{
+/* http://pubs.opengroup.org/onlinepubs/9699919799/utilities/getopts.html
+
+TODO:
+If a required argument is not found, and getopts is not silent,
+a question mark (?) is placed in VAR, OPTARG is unset, and a
+diagnostic message is printed.  If getopts is silent, then a
+colon (:) is placed in VAR and OPTARG is set to the option
+character found.
+
+Test that VAR is a valid variable name?
+
+"Whenever the shell is invoked, OPTIND shall be initialized to 1"
+*/
+       char cbuf[2];
+       const char *cp, *optstring, *var;
+       int c, n, exitcode, my_opterr;
+       unsigned count;
+
+       optstring = *++argv;
+       if (!optstring || !(var = *++argv)) {
+               bb_simple_error_msg("usage: getopts OPTSTRING VAR [ARGS]");
+               return EXIT_FAILURE;
+       }
+
+       if (argv[1])
+               argv[0] = G.global_argv[0]; /* for error messages in getopt() */
+       else
+               argv = G.global_argv;
+       cbuf[1] = '\0';
+
+       my_opterr = 0;
+       if (optstring[0] != ':') {
+               cp = get_local_var_value("OPTERR");
+               /* 0 if "OPTERR=0", 1 otherwise */
+               my_opterr = (!cp || NOT_LONE_CHAR(cp, '0'));
+       }
+
+       /* getopts stops on first non-option. Add "+" to force that */
+       /*if (optstring[0] != '+')*/ {
+               char *s = alloca(strlen(optstring) + 2);
+               sprintf(s, "+%s", optstring);
+               optstring = s;
+       }
+
+       /* Naively, now we should just
+        *      cp = get_local_var_value("OPTIND");
+        *      optind = cp ? atoi(cp) : 0;
+        *      optarg = NULL;
+        *      opterr = my_opterr;
+        *      c = getopt(string_array_len(argv), argv, optstring);
+        * and be done? Not so fast...
+        * Unlike normal getopt() usage in C programs, here
+        * each successive call will (usually) have the same argv[] CONTENTS,
+        * but not the ADDRESSES. Worse yet, it's possible that between
+        * invocations of "getopts", there will be calls to shell builtins
+        * which use getopt() internally. Example:
+        *      while getopts "abc" RES -a -bc -abc de; do
+        *              unset -ff func
+        *      done
+        * This would not work correctly: getopt() call inside "unset"
+        * modifies internal libc state which is tracking position in
+        * multi-option strings ("-abc"). At best, it can skip options
+        * or return the same option infinitely. With glibc implementation
+        * of getopt(), it would use outright invalid pointers and return
+        * garbage even _without_ "unset" mangling internal state.
+        *
+        * We resort to resetting getopt() state and calling it N times,
+        * until we get Nth result (or failure).
+        * (N == G.getopt_count is reset to 0 whenever OPTIND is [un]set).
+        */
+       GETOPT_RESET();
+       count = 0;
+       n = string_array_len(argv);
+       do {
+               optarg = NULL;
+               opterr = (count < G.getopt_count) ? 0 : my_opterr;
+               c = getopt(n, argv, optstring);
+               if (c < 0)
+                       break;
+               count++;
+       } while (count <= G.getopt_count);
+
+       /* Set OPTIND. Prevent resetting of the magic counter! */
+       set_local_var_from_halves("OPTIND", utoa(optind));
+       G.getopt_count = count; /* "next time, give me N+1'th result" */
+       GETOPT_RESET(); /* just in case */
+
+       /* Set OPTARG */
+       /* Always set or unset, never left as-is, even on exit/error:
+        * "If no option was found, or if the option that was found
+        * does not have an option-argument, OPTARG shall be unset."
+        */
+       cp = optarg;
+       if (c == '?') {
+               /* If ":optstring" and unknown option is seen,
+                * it is stored to OPTARG.
+                */
+               if (optstring[1] == ':') {
+                       cbuf[0] = optopt;
+                       cp = cbuf;
+               }
+       }
+       if (cp)
+               set_local_var_from_halves("OPTARG", cp);
+       else
+               unset_local_var("OPTARG");
+
+       /* Convert -1 to "?" */
+       exitcode = EXIT_SUCCESS;
+       if (c < 0) { /* -1: end of options */
+               exitcode = EXIT_FAILURE;
+               c = '?';
+       }
+
+       /* Set VAR */
+       cbuf[0] = c;
+       set_local_var_from_halves(var, cbuf);
+
+       return exitcode;
+}
+#endif
+
+static int FAST_FUNC builtin_source(char **argv)
+{
+       char *arg_path, *filename;
+       HFILE *input;
+       save_arg_t sv;
+       char *args_need_save;
+#if ENABLE_HUSH_FUNCTIONS
+       smallint sv_flg;
+#endif
+
+       argv = skip_dash_dash(argv);
+       filename = argv[0];
+       if (!filename) {
+               /* bash says: "bash: .: filename argument required" */
+               return 2; /* bash compat */
+       }
+       arg_path = NULL;
+       if (!strchr(filename, '/')) {
+               arg_path = find_in_path(filename);
+               if (arg_path)
+                       filename = arg_path;
+               else if (!ENABLE_HUSH_BASH_SOURCE_CURDIR) {
+                       errno = ENOENT;
+                       bb_simple_perror_msg(filename);
+                       return EXIT_FAILURE;
+               }
+       }
+       input = hfopen(filename);
+       free(arg_path);
+       if (!input) {
+               bb_perror_msg("%s", filename);
+               /* POSIX: non-interactive shell should abort here,
+                * not merely fail. So far no one complained :)
+                */
+               return EXIT_FAILURE;
+       }
+
+#if ENABLE_HUSH_FUNCTIONS
+       sv_flg = G_flag_return_in_progress;
+       /* "we are inside sourced file, ok to use return" */
+       G_flag_return_in_progress = -1;
+#endif
+       args_need_save = argv[1]; /* used as a boolean variable */
+       if (args_need_save)
+               save_and_replace_G_args(&sv, argv);
+
+       /* "false; . ./empty_line; echo Zero:$?" should print 0 */
+       G.last_exitcode = 0;
+       parse_and_run_file(input);
+       hfclose(input);
+
+       if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
+               restore_G_args(&sv, argv);
+#if ENABLE_HUSH_FUNCTIONS
+       G_flag_return_in_progress = sv_flg;
+#endif
+
+       return G.last_exitcode;
+}
+
+#if ENABLE_HUSH_TRAP
+static int FAST_FUNC builtin_trap(char **argv)
+{
+       int sig;
+       char *new_cmd;
+
+       if (!G_traps)
+               G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
+
+       argv++;
+       if (!*argv) {
+               int i;
+               /* No args: print all trapped */
+               for (i = 0; i < NSIG; ++i) {
+                       if (G_traps[i]) {
+                               printf("trap -- ");
+                               print_escaped(G_traps[i]);
+                               /* note: bash adds "SIG", but only if invoked
+                                * as "bash". If called as "sh", or if set -o posix,
+                                * then it prints short signal names.
+                                * We are printing short names: */
+                               printf(" %s\n", get_signame(i));
+                       }
+               }
+               /*fflush_all(); - done after each builtin anyway */
+               return EXIT_SUCCESS;
+       }
+
+       new_cmd = NULL;
+       /* If first arg is a number: reset all specified signals */
+       sig = bb_strtou(*argv, NULL, 10);
+       if (errno == 0) {
+               int ret;
+ process_sig_list:
+               ret = EXIT_SUCCESS;
+               while (*argv) {
+                       sighandler_t handler;
+
+                       sig = get_signum(*argv++);
+                       if (sig < 0) {
+                               ret = EXIT_FAILURE;
+                               /* Mimic bash message exactly */
+                               bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
+                               continue;
+                       }
+
+                       free(G_traps[sig]);
+                       G_traps[sig] = xstrdup(new_cmd);
+
+                       debug_printf("trap: setting SIG%s (%i) to '%s'\n",
+                               get_signame(sig), sig, G_traps[sig]);
+
+                       /* There is no signal for 0 (EXIT) */
+                       if (sig == 0)
+                               continue;
+
+                       if (new_cmd)
+                               handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
+                       else
+                               /* We are removing trap handler */
+                               handler = pick_sighandler(sig);
+                       install_sighandler(sig, handler);
+               }
+               return ret;
+       }
+
+       if (!argv[1]) { /* no second arg */
+               bb_simple_error_msg("trap: invalid arguments");
+               return EXIT_FAILURE;
+       }
+
+       /* First arg is "-": reset all specified to default */
+       /* First arg is "--": skip it, the rest is "handler SIGs..." */
+       /* Everything else: set arg as signal handler
+        * (includes "" case, which ignores signal) */
+       if (argv[0][0] == '-') {
+               if (argv[0][1] == '\0') { /* "-" */
+                       /* new_cmd remains NULL: "reset these sigs" */
+                       goto reset_traps;
+               }
+               if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
+                       argv++;
+               }
+               /* else: "-something", no special meaning */
+       }
+       new_cmd = *argv;
+ reset_traps:
+       argv++;
+       goto process_sig_list;
+}
+#endif
+
+#if ENABLE_HUSH_JOB
+static struct pipe *parse_jobspec(const char *str)
+{
+       struct pipe *pi;
+       unsigned jobnum;
+
+       if (sscanf(str, "%%%u", &jobnum) != 1) {
+               if (str[0] != '%'
+                || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
+               ) {
+                       bb_error_msg("bad argument '%s'", str);
+                       return NULL;
+               }
+               /* It is "%%", "%+" or "%" - current job */
+               jobnum = G.last_jobid;
+               if (jobnum == 0) {
+                       bb_simple_error_msg("no current job");
+                       return NULL;
+               }
+       }
+       for (pi = G.job_list; pi; pi = pi->next) {
+               if (pi->jobid == jobnum) {
+                       return pi;
+               }
+       }
+       bb_error_msg("%u: no such job", jobnum);
+       return NULL;
+}
+
+static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
+{
+       struct pipe *job;
+       const char *status_string;
+
+       checkjobs(NULL, 0 /*(no pid to wait for)*/);
+       for (job = G.job_list; job; job = job->next) {
+               if (job->alive_cmds == job->stopped_cmds)
+                       status_string = "Stopped";
+               else
+                       status_string = "Running";
+
+               printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
+       }
+
+       clean_up_last_dead_job();
+
+       return EXIT_SUCCESS;
+}
+
+/* built-in 'fg' and 'bg' handler */
+static int FAST_FUNC builtin_fg_bg(char **argv)
+{
+       int i;
+       struct pipe *pi;
+
+       if (!G_interactive_fd)
+               return EXIT_FAILURE;
+
+       /* If they gave us no args, assume they want the last backgrounded task */
+       if (!argv[1]) {
+               for (pi = G.job_list; pi; pi = pi->next) {
+                       if (pi->jobid == G.last_jobid) {
+                               goto found;
+                       }
+               }
+               bb_error_msg("%s: no current job", argv[0]);
+               return EXIT_FAILURE;
+       }
+
+       pi = parse_jobspec(argv[1]);
+       if (!pi)
+               return EXIT_FAILURE;
+ found:
+       /* TODO: bash prints a string representation
+        * of job being foregrounded (like "sleep 1 | cat") */
+       if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
+               /* Put the job into the foreground.  */
+               tcsetpgrp(G_interactive_fd, pi->pgrp);
+       }
+
+       /* Restart the processes in the job */
+       debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
+       for (i = 0; i < pi->num_cmds; i++) {
+               debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
+       }
+       pi->stopped_cmds = 0;
+
+       i = kill(- pi->pgrp, SIGCONT);
+       if (i < 0) {
+               if (errno == ESRCH) {
+                       delete_finished_job(pi);
+                       return EXIT_SUCCESS;
+               }
+               bb_simple_perror_msg("kill (SIGCONT)");
+       }
+
+       if (argv[0][0] == 'f') {
+               remove_job_from_table(pi); /* FG job shouldn't be in job table */
+               return checkjobs_and_fg_shell(pi);
+       }
+       return EXIT_SUCCESS;
+}
+#endif
+
+#if ENABLE_HUSH_KILL
+static int FAST_FUNC builtin_kill(char **argv)
+{
+       int ret = 0;
+
+# if ENABLE_HUSH_JOB
+       if (argv[1] && strcmp(argv[1], "-l") != 0) {
+               int i = 1;
+
+               do {
+                       struct pipe *pi;
+                       char *dst;
+                       int j, n;
+
+                       if (argv[i][0] != '%')
+                               continue;
+                       /*
+                        * "kill %N" - job kill
+                        * Converting to pgrp / pid kill
+                        */
+                       pi = parse_jobspec(argv[i]);
+                       if (!pi) {
+                               /* Eat bad jobspec */
+                               j = i;
+                               do {
+                                       j++;
+                                       argv[j - 1] = argv[j];
+                               } while (argv[j]);
+                               ret = 1;
+                               i--;
+                               continue;
+                       }
+                       /*
+                        * In jobs started under job control, we signal
+                        * entire process group by kill -PGRP_ID.
+                        * This happens, f.e., in interactive shell.
+                        *
+                        * Otherwise, we signal each child via
+                        * kill PID1 PID2 PID3.
+                        * Testcases:
+                        * sh -c 'sleep 1|sleep 1 & kill %1'
+                        * sh -c 'true|sleep 2 & sleep 1; kill %1'
+                        * sh -c 'true|sleep 1 & sleep 2; kill %1'
+                        */
+                       n = G_interactive_fd ? 1 : pi->num_cmds;
+                       dst = alloca(n * sizeof(int)*4);
+                       argv[i] = dst;
+                       if (G_interactive_fd)
+                               dst += sprintf(dst, " -%u", (int)pi->pgrp);
+                       else for (j = 0; j < n; j++) {
+                               struct command *cmd = &pi->cmds[j];
+                               /* Skip exited members of the job */
+                               if (cmd->pid == 0)
+                                       continue;
+                               /*
+                                * kill_main has matching code to expect
+                                * leading space. Needed to not confuse
+                                * negative pids with "kill -SIGNAL_NO" syntax
+                                */
+                               dst += sprintf(dst, " %u", (int)cmd->pid);
+                       }
+                       *dst = '\0';
+               } while (argv[++i]);
+       }
+# endif
+
+       if (argv[1] || ret == 0) {
+               ret = run_applet_main(argv, kill_main);
+       }
+       /* else: ret = 1, "kill %bad_jobspec" case */
+       return ret;
+}
+#endif
+
+#if ENABLE_HUSH_WAIT
+/* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
+# if !ENABLE_HUSH_JOB
+#  define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
+# endif
+static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
+{
+       int ret = 0;
+       for (;;) {
+               int sig;
+               sigset_t oldset;
+
+               if (!sigisemptyset(&G.pending_set))
+                       goto check_sig;
+
+               /* waitpid is not interruptible by SA_RESTARTed
+                * signals which we use. Thus, this ugly dance:
+                */
+
+               /* Make sure possible SIGCHLD is stored in kernel's
+                * pending signal mask before we call waitpid.
+                * Or else we may race with SIGCHLD, lose it,
+                * and get stuck in sigsuspend...
+                */
+               sigfillset(&oldset); /* block all signals, remember old set */
+               sigprocmask2(SIG_SETMASK, &oldset);
+
+               if (!sigisemptyset(&G.pending_set)) {
+                       /* Crap! we raced with some signal! */
+                       goto restore;
+               }
+
+               /*errno = 0; - checkjobs does this */
+/* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
+               ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
+               debug_printf_exec("checkjobs:%d\n", ret);
+# if ENABLE_HUSH_JOB
+               if (waitfor_pipe) {
+                       int rcode = job_exited_or_stopped(waitfor_pipe);
+                       debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
+                       if (rcode >= 0) {
+                               ret = rcode;
+                               sigprocmask(SIG_SETMASK, &oldset, NULL);
+                               break;
+                       }
+               }
+# endif
+               /* if ECHILD, there are no children (ret is -1 or 0) */
+               /* if ret == 0, no children changed state */
+               /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
+               if (errno == ECHILD || ret) {
+                       ret--;
+                       if (ret < 0) /* if ECHILD, may need to fix "ret" */
+                               ret = 0;
+# if ENABLE_HUSH_BASH_COMPAT
+                       if (waitfor_pid == -1 && errno == ECHILD) {
+                               /* exitcode of "wait -n" with no children is 127, not 0 */
+                               ret = 127;
+                       }
+# endif
+                       sigprocmask(SIG_SETMASK, &oldset, NULL);
+                       break;
+               }
+               /* Wait for SIGCHLD or any other signal */
+               /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
+               /* Note: sigsuspend invokes signal handler */
+               sigsuspend(&oldset);
+               /* ^^^ add "sigdelset(&oldset, SIGCHLD)" before sigsuspend
+                * to make sure SIGCHLD is not masked off?
+                * It was reported that this:
+                *      fn() { : | return; }
+                *      shopt -s lastpipe
+                *      fn
+                *      exec hush SCRIPT
+                * under bash 4.4.23 runs SCRIPT with SIGCHLD masked,
+                * making "wait" commands in SCRIPT block forever.
+                */
+ restore:
+               sigprocmask(SIG_SETMASK, &oldset, NULL);
+ check_sig:
+               /* So, did we get a signal? */
+               sig = check_and_run_traps();
+               if (sig /*&& sig != SIGCHLD - always true */) {
+                       /* Do this for any (non-ignored) signal, not only for ^C */
+                       ret = 128 | sig;
+                       break;
+               }
+               /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
+       }
+       return ret;
+}
+
+static int FAST_FUNC builtin_wait(char **argv)
+{
+       int ret;
+       int status;
+
+       argv = skip_dash_dash(argv);
+# if ENABLE_HUSH_BASH_COMPAT
+       if (argv[0] && strcmp(argv[0], "-n") == 0) {
+               /* wait -n */
+               /* (bash accepts "wait -n PID" too and ignores PID) */
+               G.dead_job_exitcode = -1;
+               return wait_for_child_or_signal(NULL, -1 /*no job, wait for one job*/);
+       }
+# endif
+       if (argv[0] == NULL) {
+               /* Don't care about wait results */
+               /* Note 1: must wait until there are no more children */
+               /* Note 2: must be interruptible */
+               /* Examples:
+                * $ sleep 3 & sleep 6 & wait
+                * [1] 30934 sleep 3
+                * [2] 30935 sleep 6
+                * [1] Done                   sleep 3
+                * [2] Done                   sleep 6
+                * $ sleep 3 & sleep 6 & wait
+                * [1] 30936 sleep 3
+                * [2] 30937 sleep 6
+                * [1] Done                   sleep 3
+                * ^C <-- after ~4 sec from keyboard
+                * $
+                */
+               return wait_for_child_or_signal(NULL, 0 /*no job and no pid to wait for*/);
+       }
+
+       do {
+               pid_t pid = bb_strtou(*argv, NULL, 10);
+               if (errno || pid <= 0) {
+# if ENABLE_HUSH_JOB
+                       if (argv[0][0] == '%') {
+                               struct pipe *wait_pipe;
+                               ret = 127; /* bash compat for bad jobspecs */
+                               wait_pipe = parse_jobspec(*argv);
+                               if (wait_pipe) {
+                                       ret = job_exited_or_stopped(wait_pipe);
+                                       if (ret < 0) {
+                                               ret = wait_for_child_or_signal(wait_pipe, 0);
+                                       } else {
+                                               /* waiting on "last dead job" removes it */
+                                               clean_up_last_dead_job();
+                                       }
+                               }
+                               /* else: parse_jobspec() already emitted error msg */
+                               continue;
+                       }
+# endif
+                       /* mimic bash message */
+                       bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
+                       ret = EXIT_FAILURE;
+                       continue; /* bash checks all argv[] */
+               }
+
+               /* Do we have such child? */
+               ret = waitpid(pid, &status, WNOHANG);
+               if (ret < 0) {
+                       /* No */
+                       ret = 127;
+                       if (errno == ECHILD) {
+                               if (pid == G.last_bg_pid) {
+                                       /* "wait $!" but last bg task has already exited. Try:
+                                        * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
+                                        * In bash it prints exitcode 0, then 3.
+                                        * In dash, it is 127.
+                                        */
+                                       ret = G.last_bg_pid_exitcode;
+                               } else {
+                                       /* Example: "wait 1". mimic bash message */
+                                       bb_error_msg("wait: pid %u is not a child of this shell", (unsigned)pid);
+                               }
+                       } else {
+                               /* ??? */
+                               bb_perror_msg("wait %s", *argv);
+                       }
+                       continue; /* bash checks all argv[] */
+               }
+               if (ret == 0) {
+                       /* Yes, and it still runs */
+                       ret = wait_for_child_or_signal(NULL, pid);
+               } else {
+                       /* Yes, and it just exited */
+                       process_wait_result(NULL, pid, status);
+                       ret = WEXITSTATUS(status);
+                       if (WIFSIGNALED(status))
+                               ret = 128 | WTERMSIG(status);
+               }
+       } while (*++argv);
+
+       return ret;
+}
+#endif
+
+#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
+static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
+{
+       if (argv[1]) {
+               def = bb_strtou(argv[1], NULL, 10);
+               if (errno || def < def_min || argv[2]) {
+                       bb_error_msg("%s: bad arguments", argv[0]);
+                       def = UINT_MAX;
+               }
+       }
+       return def;
+}
+#endif
+
+#if ENABLE_HUSH_LOOPS
+static int FAST_FUNC builtin_break(char **argv)
+{
+       unsigned depth;
+       if (G.depth_of_loop == 0) {
+               bb_error_msg("%s: only meaningful in a loop", argv[0]);
+               /* if we came from builtin_continue(), need to undo "= 1" */
+               G.flag_break_continue = 0;
+               return EXIT_SUCCESS; /* bash compat */
+       }
+       G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
+
+       G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
+       if (depth == UINT_MAX)
+               G.flag_break_continue = BC_BREAK;
+       if (G.depth_of_loop < depth)
+               G.depth_break_continue = G.depth_of_loop;
+
+       return EXIT_SUCCESS;
+}
+
+static int FAST_FUNC builtin_continue(char **argv)
+{
+       G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
+       return builtin_break(argv);
+}
+#endif
+
+#if ENABLE_HUSH_FUNCTIONS
+static int FAST_FUNC builtin_return(char **argv)
+{
+       int rc;
+
+       if (G_flag_return_in_progress != -1) {
+               bb_error_msg("%s: not in a function or sourced script", argv[0]);
+               return EXIT_FAILURE; /* bash compat */
+       }
+
+       G_flag_return_in_progress = 1;
+
+       /* bash:
+        * out of range: wraps around at 256, does not error out
+        * non-numeric param:
+        * f() { false; return qwe; }; f; echo $?
+        * bash: return: qwe: numeric argument required  <== we do this
+        * 255  <== we also do this
+        */
+       rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
+# if ENABLE_HUSH_TRAP
+       if (argv[1]) { /* "return ARG" inside a running trap sets $? */
+               debug_printf_exec("G.return_exitcode=%d\n", rc);
+               G.return_exitcode = rc;
+       }
+# endif
+       return rc;
+}
+#endif
+
+#if ENABLE_HUSH_TIMES
+static int FAST_FUNC builtin_times(char **argv UNUSED_PARAM)
+{
+       static const uint8_t times_tbl[] ALIGN1 = {
+               ' ',  offsetof(struct tms, tms_utime),
+               '\n', offsetof(struct tms, tms_stime),
+               ' ',  offsetof(struct tms, tms_cutime),
+               '\n', offsetof(struct tms, tms_cstime),
+               0
+       };
+       const uint8_t *p;
+       unsigned clk_tck;
+       struct tms buf;
+
+       clk_tck = bb_clk_tck();
+
+       times(&buf);
+       p = times_tbl;
+       do {
+               unsigned sec, frac;
+               unsigned long t;
+               t = *(clock_t *)(((char *) &buf) + p[1]);
+               sec = t / clk_tck;
+               frac = t % clk_tck;
+               printf("%um%u.%03us%c",
+                       sec / 60, sec % 60,
+                       (frac * 1000) / clk_tck,
+                       p[0]);
+               p += 2;
+       } while (*p);
+
+       return EXIT_SUCCESS;
+}
+#endif
+
+#if ENABLE_HUSH_MEMLEAK
+static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
+{
+       void *p;
+       unsigned long l;
+
+# ifdef M_TRIM_THRESHOLD
+       /* Optional. Reduces probability of false positives */
+       malloc_trim(0);
+# endif
+       /* Crude attempt to find where "free memory" starts,
+        * sans fragmentation. */
+       p = malloc(240);
+       l = (unsigned long)p;
+       free(p);
+       p = malloc(3400);
+       if (l < (unsigned long)p) l = (unsigned long)p;
+       free(p);
+
+
+# if 0  /* debug */
+       {
+               struct mallinfo mi = mallinfo();
+               printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
+                       mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
+       }
+# endif
+
+       if (!G.memleak_value)
+               G.memleak_value = l;
+
+       l -= G.memleak_value;
+       if ((long)l < 0)
+               l = 0;
+       l /= 1024;
+       if (l > 127)
+               l = 127;
+
+       /* Exitcode is "how many kilobytes we leaked since 1st call" */
+       return l;
+}
+#endif