"env grep" - add support for regular expression matches

When CONFIG_REGEX is enabled, the new option "-e" becomes available
which causes regular expression matches to be used.  This allows for
example things like these:

- print all MAC addresses:

	=> env grep -e eth.*addr
	eth1addr=00:10:ec:80:c5:15
	ethaddr=00:10:ec:00:c5:15

- print all variables that have at least 2 colons in their value:

	=> env grep -v -e :.*:
	addip=setenv bootargs ${bootargs} ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}:${netdev}:off
	panic=1
	eth1addr=00:10:ec:80:c5:15
	ethaddr=00:10:ec:00:c5:15
	ver=U-Boot 2013.04-rc1-00289-g497746b-dirty (Mar 22 2013 - 12:50:25)

etc.

Signed-off-by: Wolfgang Denk <wd@denx.de>

diff --git a/common/cmd_nvedit.c b/common/cmd_nvedit.c
index 9158b96224a2c87657a52fad4d68e989abb109ac..f8dc38e89a2d3e0e54c1abf28cdee09cc32e0e24 100644 (file)
--- a/common/cmd_nvedit.c
+++ b/common/cmd_nvedit.c
@@ -165,12 +165,13 @@ static int do_env_grep(cmd_tbl_t *cmdtp, int flag,
                       int argc, char * const argv[])
 {
        char *res = NULL;
-       int len, grep_flags;
+       int len, grep_how, grep_what;
 
        if (argc < 2)
                return CMD_RET_USAGE;
 
-       grep_flags = H_MATCH_BOTH;
+       grep_how  = H_MATCH_SUBSTR;     /* default: substring search    */
+       grep_what = H_MATCH_BOTH;       /* default: grep names and values */
 
        while (argc > 1 && **(argv + 1) == '-') {
                char *arg = *++argv;
@@ -178,14 +179,19 @@ static int do_env_grep(cmd_tbl_t *cmdtp, int flag,
                --argc;
                while (*++arg) {
                        switch (*arg) {
+#ifdef CONFIG_REGEX
+                       case 'e':               /* use regex matching */
+                               grep_how  = H_MATCH_REGEX;
+                               break;
+#endif
                        case 'n':               /* grep for name */
-                               grep_flags = H_MATCH_KEY;
+                               grep_what = H_MATCH_KEY;
                                break;
                        case 'v':               /* grep for value */
-                               grep_flags = H_MATCH_DATA;
+                               grep_what = H_MATCH_DATA;
                                break;
                        case 'b':               /* grep for both */
-                               grep_flags = H_MATCH_BOTH;
+                               grep_what = H_MATCH_BOTH;
                                break;
                        case '-':
                                goto DONE;
@@ -197,7 +203,7 @@ static int do_env_grep(cmd_tbl_t *cmdtp, int flag,
 
 DONE:
        len = hexport_r(&env_htab, '\n',
-                       flag | grep_flags | H_MATCH_SUBSTR,
+                       flag | grep_what | grep_how,
                        &res, 0, argc, argv);
 
        if (len > 0) {
@@ -1153,8 +1159,12 @@ static char env_help_text[] =
        "env flags - print variables that have non-default flags\n"
 #endif
 #if defined(CONFIG_CMD_GREPENV)
+#ifdef CONFIG_REGEX
+       "env grep [-e] [-n | -v | -b] string [...] - search environment\n"
+#else
        "env grep [-n | -v | -b] string [...] - search environment\n"
 #endif
+#endif
 #if defined(CONFIG_CMD_IMPORTENV)
        "env import [-d] [-t | -b | -c] addr [size] - import environment\n"
 #endif
@@ -1200,8 +1210,15 @@ U_BOOT_CMD_COMPLETE(
 U_BOOT_CMD_COMPLETE(
        grepenv, CONFIG_SYS_MAXARGS, 0,  do_env_grep,
        "search environment variables",
+#ifdef CONFIG_REGEX
+       "[-e] [-n | -v | -b] string ...\n"
+#else
        "[-n | -v | -b] string ...\n"
+#endif
        "    - list environment name=value pairs matching 'string'\n"
+#ifdef CONFIG_REGEX
+       "      \"-e\": enable regular expressions;\n"
+#endif
        "      \"-n\": search variable names; \"-v\": search values;\n"
        "      \"-b\": search both names and values (default)",
        var_complete

diff --git a/include/search.h b/include/search.h
index d06a2017a5c8e405db3bb0d0d06b045f8e824725..d9ac8dfa071c6a24b7b49635900003436ab34105 100644 (file)
--- a/include/search.h
+++ b/include/search.h
@@ -129,7 +129,8 @@ extern int hwalk_r(struct hsearch_data *__htab, int (*callback)(ENTRY *));
 #define H_MATCH_DATA   (1 << 5) /* search/grep data = variable values       */
 #define H_MATCH_BOTH   (H_MATCH_KEY | H_MATCH_DATA) /* search/grep both     */
 #define H_MATCH_IDENT  (1 << 6) /* search for indentical strings            */
-#define H_MATCH_SUBSTR  (1 << 7) /* search for substring matches            */
-#define H_MATCH_METHOD (H_MATCH_IDENT | H_MATCH_SUBSTR)
+#define H_MATCH_SUBSTR (1 << 7) /* search for substring matches             */
+#define H_MATCH_REGEX  (1 << 8) /* search for regular expression matches    */
+#define H_MATCH_METHOD (H_MATCH_IDENT | H_MATCH_SUBSTR | H_MATCH_REGEX)
 
 #endif /* search.h */

diff --git a/lib/hashtable.c b/lib/hashtable.c
index 1703941a5ab3f704d905ec46b9262a5994e26925..6050dd0829f9ac3ce3bc399d1cc7e9428af3afa0 100644 (file)
--- a/lib/hashtable.c
+++ b/lib/hashtable.c
@@ -57,6 +57,7 @@
 #include <env_callback.h>
 #include <env_flags.h>
 #include <search.h>
+#include <slre.h>
 
 /*
  * [Aho,Sethi,Ullman] Compilers: Principles, Techniques and Tools, 1986
@@ -540,7 +541,7 @@ static int cmpkey(const void *p1, const void *p2)
        return (strcmp(e1->key, e2->key));
 }
 
-static int match_string(int flag, const char *str, const char *pat)
+static int match_string(int flag, const char *str, const char *pat, void *priv)
 {
        switch (flag & H_MATCH_METHOD) {
        case H_MATCH_IDENT:
@@ -551,6 +552,17 @@ static int match_string(int flag, const char *str, const char *pat)
                if (strstr(str, pat))
                        return 1;
                break;
+#ifdef CONFIG_REGEX
+       case H_MATCH_REGEX:
+               {
+                       struct slre *slrep = (struct slre *)priv;
+                       struct cap caps[slrep->num_caps + 2];
+
+                       if (slre_match(slrep, str, strlen(str), caps))
+                               return 1;
+               }
+               break;
+#endif
        default:
                printf("## ERROR: unsupported match method: 0x%02x\n",
                        flag & H_MATCH_METHOD);
@@ -563,14 +575,25 @@ static int match_entry(ENTRY *ep, int flag,
                 int argc, char * const argv[])
 {
        int arg;
+       void *priv = NULL;
 
        for (arg = 1; arg < argc; ++arg) {
+#ifdef CONFIG_REGEX
+               struct slre slre;
+
+               if (slre_compile(&slre, argv[arg]) == 0) {
+                       printf("Error compiling regex: %s\n", slre.err_str);
+                       return 0;
+               }
+
+               priv = (void *)&slre;
+#endif
                if (flag & H_MATCH_KEY) {
-                       if (match_string(flag, ep->key, argv[arg]))
+                       if (match_string(flag, ep->key, argv[arg], priv))
                                return 1;
                }
                if (flag & H_MATCH_DATA) {
-                       if (match_string(flag, ep->data, argv[arg]))
+                       if (match_string(flag, ep->data, argv[arg], priv))
                                return 1;
                }
        }