From 9571f1ac6f998d2cf1697c35ae45eefa572bf681 Mon Sep 17 00:00:00 2001 From: Roland Gaudig Date: Fri, 23 Jul 2021 12:29:19 +0000 Subject: [PATCH] cmd: printf: import busybox-1.33.1 printf.c Import printf.c from the Busybox project, which provides Bash like format string handling. src-url: https://git.busybox.net/busybox/ commit bcc5b0e6caca6c7602a6a41f "Bump version to 1.33.1" version: 1.33.1 Signed-off-by: Roland Gaudig --- cmd/printf.c | 455 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 455 insertions(+) create mode 100644 cmd/printf.c diff --git a/cmd/printf.c b/cmd/printf.c new file mode 100644 index 0000000000..a20fc33013 --- /dev/null +++ b/cmd/printf.c @@ -0,0 +1,455 @@ +/* vi: set sw=4 ts=4: */ +/* + * printf - format and print data + * + * Copyright 1999 Dave Cinege + * Portions copyright (C) 1990-1996 Free Software Foundation, Inc. + * + * Licensed under GPLv2 or later, see file LICENSE in this source tree. + */ +/* Usage: printf format [argument...] + * + * A front end to the printf function that lets it be used from the shell. + * + * Backslash escapes: + * + * \" = double quote + * \\ = backslash + * \a = alert (bell) + * \b = backspace + * \c = produce no further output + * \f = form feed + * \n = new line + * \r = carriage return + * \t = horizontal tab + * \v = vertical tab + * \0ooo = octal number (ooo is 0 to 3 digits) + * \xhhh = hexadecimal number (hhh is 1 to 3 digits) + * + * Additional directive: + * + * %b = print an argument string, interpreting backslash escapes + * + * The 'format' argument is re-used as many times as necessary + * to convert all of the given arguments. + * + * David MacKenzie + */ +/* 19990508 Busy Boxed! Dave Cinege */ + +//config:config PRINTF +//config: bool "printf (3.8 kb)" +//config: default y +//config: help +//config: printf is used to format and print specified strings. +//config: It's similar to 'echo' except it has more options. + +//applet:IF_PRINTF(APPLET_NOFORK(printf, printf, BB_DIR_USR_BIN, BB_SUID_DROP, printf)) + +//kbuild:lib-$(CONFIG_PRINTF) += printf.o +//kbuild:lib-$(CONFIG_ASH_PRINTF) += printf.o +//kbuild:lib-$(CONFIG_HUSH_PRINTF) += printf.o + +//usage:#define printf_trivial_usage +//usage: "FORMAT [ARG]..." +//usage:#define printf_full_usage "\n\n" +//usage: "Format and print ARG(s) according to FORMAT (a-la C printf)" +//usage: +//usage:#define printf_example_usage +//usage: "$ printf \"Val=%d\\n\" 5\n" +//usage: "Val=5\n" + +#include "libbb.h" + +/* A note on bad input: neither bash 3.2 nor coreutils 6.10 stop on it. + * They report it: + * bash: printf: XXX: invalid number + * printf: XXX: expected a numeric value + * bash: printf: 123XXX: invalid number + * printf: 123XXX: value not completely converted + * but then they use 0 (or partially converted numeric prefix) as a value + * and continue. They exit with 1 in this case. + * Both accept insane field width/precision (e.g. %9999999999.9999999999d). + * Both print error message and assume 0 if %*.*f width/precision is "bad" + * (but negative numbers are not "bad"). + * Both accept negative numbers for %u specifier. + * + * We try to be compatible. + */ + +typedef void FAST_FUNC (*converter)(const char *arg, void *result); + +static int multiconvert(const char *arg, void *result, converter convert) +{ + if (*arg == '"' || *arg == '\'') { + arg = utoa((unsigned char)arg[1]); + } + errno = 0; + convert(arg, result); + if (errno) { + bb_error_msg("invalid number '%s'", arg); + return 1; + } + return 0; +} + +static void FAST_FUNC conv_strtoull(const char *arg, void *result) +{ + /* Allow leading '+' - bb_strtoull() by itself does not allow it, + * and probably shouldn't (other callers might require purely numeric + * inputs to be allowed. + */ + if (arg[0] == '+') + arg++; + *(unsigned long long*)result = bb_strtoull(arg, NULL, 0); + /* both coreutils 6.10 and bash 3.2: + * $ printf '%x\n' -2 + * fffffffffffffffe + * Mimic that: + */ + if (errno) { + *(unsigned long long*)result = bb_strtoll(arg, NULL, 0); + } +} +static void FAST_FUNC conv_strtoll(const char *arg, void *result) +{ + if (arg[0] == '+') + arg++; + *(long long*)result = bb_strtoll(arg, NULL, 0); +} +static void FAST_FUNC conv_strtod(const char *arg, void *result) +{ + char *end; + /* Well, this one allows leading whitespace... so what? */ + /* What I like much less is that "-" accepted too! :( */ + *(double*)result = strtod(arg, &end); + if (end[0]) { + errno = ERANGE; + *(double*)result = 0; + } +} + +/* Callers should check errno to detect errors */ +static unsigned long long my_xstrtoull(const char *arg) +{ + unsigned long long result; + if (multiconvert(arg, &result, conv_strtoull)) + result = 0; + return result; +} +static long long my_xstrtoll(const char *arg) +{ + long long result; + if (multiconvert(arg, &result, conv_strtoll)) + result = 0; + return result; +} +static double my_xstrtod(const char *arg) +{ + double result; + multiconvert(arg, &result, conv_strtod); + return result; +} + +/* Handles %b; return 1 if output is to be short-circuited by \c */ +static int print_esc_string(const char *str) +{ + char c; + while ((c = *str) != '\0') { + str++; + if (c == '\\') { + /* %b also accepts 4-digit octals of the form \0### */ + if (*str == '0') { + if ((unsigned char)(str[1] - '0') < 8) { + /* 2nd char is 0..7: skip leading '0' */ + str++; + } + } + else if (*str == 'c') { + return 1; + } + { + /* optimization: don't force arg to be on-stack, + * use another variable for that. */ + const char *z = str; + c = bb_process_escape_sequence(&z); + str = z; + } + } + putchar(c); + } + + return 0; +} + +static void print_direc(char *format, unsigned fmt_length, + int field_width, int precision, + const char *argument) +{ + long long llv; + double dv; + char saved; + char *have_prec, *have_width; + + saved = format[fmt_length]; + format[fmt_length] = '\0'; + + have_prec = strstr(format, ".*"); + have_width = strchr(format, '*'); + if (have_width - 1 == have_prec) + have_width = NULL; + + /* multiconvert sets errno = 0, but %s needs it cleared */ + errno = 0; + + switch (format[fmt_length - 1]) { + case 'c': + printf(format, *argument); + break; + case 'd': + case 'i': + llv = my_xstrtoll(skip_whitespace(argument)); + print_long: + if (!have_width) { + if (!have_prec) + printf(format, llv); + else + printf(format, precision, llv); + } else { + if (!have_prec) + printf(format, field_width, llv); + else + printf(format, field_width, precision, llv); + } + break; + case 'o': + case 'u': + case 'x': + case 'X': + llv = my_xstrtoull(skip_whitespace(argument)); + /* cheat: unsigned long and long have same width, so... */ + goto print_long; + case 's': + /* Are char* and long long the same? */ + if (sizeof(argument) == sizeof(llv)) { + llv = (long long)(ptrdiff_t)argument; + goto print_long; + } else { + /* Hope compiler will optimize it out by moving call + * instruction after the ifs... */ + if (!have_width) { + if (!have_prec) + printf(format, argument, /*unused:*/ argument, argument); + else + printf(format, precision, argument, /*unused:*/ argument); + } else { + if (!have_prec) + printf(format, field_width, argument, /*unused:*/ argument); + else + printf(format, field_width, precision, argument); + } + break; + } + case 'f': + case 'e': + case 'E': + case 'g': + case 'G': + dv = my_xstrtod(argument); + if (!have_width) { + if (!have_prec) + printf(format, dv); + else + printf(format, precision, dv); + } else { + if (!have_prec) + printf(format, field_width, dv); + else + printf(format, field_width, precision, dv); + } + break; + } /* switch */ + + format[fmt_length] = saved; +} + +/* Handle params for "%*.*f". Negative numbers are ok (compat). */ +static int get_width_prec(const char *str) +{ + int v = bb_strtoi(str, NULL, 10); + if (errno) { + bb_error_msg("invalid number '%s'", str); + v = 0; + } + return v; +} + +/* Print the text in FORMAT, using ARGV for arguments to any '%' directives. + Return advanced ARGV. */ +static char **print_formatted(char *f, char **argv, int *conv_err) +{ + char *direc_start; /* Start of % directive. */ + unsigned direc_length; /* Length of % directive. */ + int field_width; /* Arg to first '*' */ + int precision; /* Arg to second '*' */ + char **saved_argv = argv; + + for (; *f; ++f) { + switch (*f) { + case '%': + direc_start = f++; + direc_length = 1; + field_width = precision = 0; + if (*f == '%') { + bb_putchar('%'); + break; + } + if (*f == 'b') { + if (*argv) { + if (print_esc_string(*argv)) + return saved_argv; /* causes main() to exit */ + ++argv; + } + break; + } + if (*f && strchr("-+ #", *f)) { + ++f; + ++direc_length; + } + if (*f == '*') { + ++f; + ++direc_length; + if (*argv) + field_width = get_width_prec(*argv++); + } else { + while (isdigit(*f)) { + ++f; + ++direc_length; + } + } + if (*f == '.') { + ++f; + ++direc_length; + if (*f == '*') { + ++f; + ++direc_length; + if (*argv) + precision = get_width_prec(*argv++); + } else { + while (isdigit(*f)) { + ++f; + ++direc_length; + } + } + } + + /* Remove "lLhz" size modifiers, repeatedly. + * bash does not like "%lld", but coreutils + * happily takes even "%Llllhhzhhzd"! + * We are permissive like coreutils */ + while ((*f | 0x20) == 'l' || *f == 'h' || *f == 'z') { + overlapping_strcpy(f, f + 1); + } + /* Add "ll" if integer modifier, then print */ + { + static const char format_chars[] ALIGN1 = "diouxXfeEgGcs"; + char *p = strchr(format_chars, *f); + /* needed - try "printf %" without it */ + if (p == NULL || *f == '\0') { + bb_error_msg("%s: invalid format", direc_start); + /* causes main() to exit with error */ + return saved_argv - 1; + } + ++direc_length; + if (p - format_chars <= 5) { + /* it is one of "diouxX" */ + p = xmalloc(direc_length + 3); + memcpy(p, direc_start, direc_length); + p[direc_length + 1] = p[direc_length - 1]; + p[direc_length - 1] = 'l'; + p[direc_length] = 'l'; + //bb_error_msg("<%s>", p); + direc_length += 2; + direc_start = p; + } else { + p = NULL; + } + if (*argv) { + print_direc(direc_start, direc_length, field_width, + precision, *argv++); + } else { + print_direc(direc_start, direc_length, field_width, + precision, ""); + } + *conv_err |= errno; + free(p); + } + break; + case '\\': + if (*++f == 'c') { + return saved_argv; /* causes main() to exit */ + } + bb_putchar(bb_process_escape_sequence((const char **)&f)); + f--; + break; + default: + putchar(*f); + } + } + + return argv; +} + +int printf_main(int argc UNUSED_PARAM, char **argv) +{ + int conv_err; + char *format; + char **argv2; + + /* We must check that stdout is not closed. + * The reason for this is highly non-obvious. + * printf_main is used from shell. + * Shell must correctly handle 'printf "%s" foo' + * if stdout is closed. With stdio, output gets shoveled into + * stdout buffer, and even fflush cannot clear it out. It seems that + * even if libc receives EBADF on write attempts, it feels determined + * to output data no matter what. So it will try later, + * and possibly will clobber future output. Not good. */ +// TODO: check fcntl() & O_ACCMODE == O_WRONLY or O_RDWR? + if (fcntl(1, F_GETFL) == -1) + return 1; /* match coreutils 6.10 (sans error msg to stderr) */ + //if (dup2(1, 1) != 1) - old way + // return 1; + + /* bash builtin errors out on "printf '-%s-\n' foo", + * coreutils-6.9 works. Both work with "printf -- '-%s-\n' foo". + * We will mimic coreutils. */ + if (argv[1] && argv[1][0] == '-' && argv[1][1] == '-' && !argv[1][2]) + argv++; + if (!argv[1]) { + if (ENABLE_ASH_PRINTF + && applet_name[0] != 'p' + ) { + bb_simple_error_msg("usage: printf FORMAT [ARGUMENT...]"); + return 2; /* bash compat */ + } + bb_show_usage(); + } + + format = argv[1]; + argv2 = argv + 2; + + conv_err = 0; + do { + argv = argv2; + argv2 = print_formatted(format, argv, &conv_err); + } while (argv2 > argv && *argv2); + + /* coreutils compat (bash doesn't do this): + if (*argv) + fprintf(stderr, "excess args ignored"); + */ + + return (argv2 < argv) /* if true, print_formatted errored out */ + || conv_err; /* print_formatted saw invalid number */ +} -- 2.39.5