libbb: unified config parser (By Vladimir Dronnikov)

mdev: use it

function                                             old     new   delta
config_read                                            -     400    +400
config_open                                            -      43     +43
config_close                                           -       9      +9
qrealloc                                              33      36      +3
compare_keys                                         735     737      +2
xstrtoull_range_sfx                                  296     295      -1
qgravechar                                           109     106      -3
get_address                                          181     178      -3
next_token                                           928     923      -5
sv_main                                             1228    1222      -6
find_main                                            418     406     -12
next_field                                            32       -     -32
make_device                                         1269    1184     -85
------------------------------------------------------------------------------
(add/remove: 3/1 grow/shrink: 2/7 up/down: 457/-147)          Total: 310 bytes

1 files changed, 25 insertions, 56 deletions

diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index dd9522999..c61521cbb 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -25,16 +25,6 @@ struct globals {
 /* We use additional 64+ bytes in make_device() */
 #define SCRATCH_SIZE 80
 
-static char *next_field(char *s)
-{
-        char *end = skip_non_whitespace(s);
-        s = skip_whitespace(end);
-        *end = '\0';
-        if (*s == '\0')
-                s = NULL;
-        return s;
-}
-
 /* Builds an alias path.
  * This function potentionally reallocates the alias parameter.
  */
@@ -104,33 +94,26 @@ static void make_device(char *path, int delete)
                 type = S_IFBLK;
 
         if (ENABLE_FEATURE_MDEV_CONF) {
-                FILE *fp;
-                char *line, *val, *next;
-                unsigned lineno = 0;
+                parser_t parser;
+                char *tokens[5];
 
                 /* If we have config file, look up user settings */
-                fp = fopen_or_warn("/etc/mdev.conf", "r");
-                if (!fp)
+                if (!config_open(&parser, "/etc/mdev.conf"))
                         goto end_parse;
 
-                while ((line = xmalloc_fgetline(fp)) != NULL) {
+                while (config_read(&parser, tokens, 4, 3, " \t", '#')) {
                         regmatch_t off[1+9*ENABLE_FEATURE_MDEV_RENAME_REGEXP];
-
-                        ++lineno;
-                        trim(line);
-                        if (!line[0])
-                                goto next_line;
+                        char *val;
 
                         /* Fields: regex uid:gid mode [alias] [cmd] */
 
                         /* 1st field: regex to match this device */
-                        next = next_field(line);
                         {
                                 regex_t match;
                                 int result;
 
                                 /* Is this it? */
-                                xregcomp(&match, line, REG_EXTENDED);
+                                xregcomp(&match, tokens[0], REG_EXTENDED);
                                 result = regexec(&match, device_name, ARRAY_SIZE(off), off, 0);
                                 regfree(&match);
 
@@ -147,7 +130,7 @@ static void make_device(char *path, int delete)
                                 if (result || off[0].rm_so
                                  || ((int)off[0].rm_eo != (int)strlen(device_name))
                                 ) {
-                                        goto next_line;
+                                        continue;
                                 }
                         }
 
@@ -155,15 +138,11 @@ static void make_device(char *path, int delete)
                          * after parsing the rest of fields */
 
                         /* 2nd field: uid:gid - device ownership */
-                        if (!next) /* field must exist */
-                                bb_error_msg_and_die("bad line %u", lineno);
-                        val = next;
-                        next = next_field(val);
                         {
                                 struct passwd *pass;
                                 struct group *grp;
-                                char *str_uid = val;
-                                char *str_gid = strchrnul(val, ':');
+                                char *str_uid = tokens[1];
+                                char *str_gid = strchrnul(str_uid, ':');
 
                                 if (*str_gid)
                                         *str_gid++ = '\0';
@@ -182,33 +161,30 @@ static void make_device(char *path, int delete)
                         }
 
                         /* 3rd field: mode - device permissions */
-                        if (!next) /* field must exist */
-                                bb_error_msg_and_die("bad line %u", lineno);
-                        val = next;
-                        next = next_field(val);
-                        mode = strtoul(val, NULL, 8);
+                        mode = strtoul(tokens[2], NULL, 8);
 
+                        val = tokens[3];
                         /* 4th field (opt): >alias */
 #if ENABLE_FEATURE_MDEV_RENAME
-                        if (!next)
+                        if (!val)
                                 break;
-                        if (*next == '>' || *next == '=') {
-#if ENABLE_FEATURE_MDEV_RENAME_REGEXP
+                        aliaslink = *val;
+                        if (aliaslink == '>' || aliaslink == '=') {
                                 char *s, *p;
                                 unsigned i, n;
-
-                                aliaslink = *next;
-                                val = next;
-                                next = next_field(val);
+                                char *a = val;
+                                s = strchr(val, ' ');
+                                val = (s && s[1]) ? s+1 : NULL;
+#if ENABLE_FEATURE_MDEV_RENAME_REGEXP
                                 /* substitute %1..9 with off[1..9], if any */
                                 n = 0;
-                                s = val;
+                                s = a;
                                 while (*s)
                                         if (*s++ == '%')
                                                 n++;
 
-                                p = alias = xzalloc(strlen(val) + n * strlen(device_name));
-                                s = val + 1;
+                                p = alias = xzalloc(strlen(a) + n * strlen(device_name));
+                                s = a + 1;
                                 while (*s) {
                                         *p = *s;
                                         if ('%' == *s) {
@@ -224,24 +200,20 @@ static void make_device(char *path, int delete)
                                         s++;
                                 }
 #else
-                                aliaslink = *next;
-                                val = next;
-                                next = next_field(val);
-                                alias = xstrdup(val + 1);
+                                alias = xstrdup(a + 1);
 #endif
                         }
 #endif /* ENABLE_FEATURE_MDEV_RENAME */
 
                         /* The rest (opt): command to run */
-                        if (!next)
+                        if (!val)
                                 break;
-                        val = next;
                         if (ENABLE_FEATURE_MDEV_EXEC) {
                                 const char *s = "@$*";
                                 const char *s2 = strchr(s, *val);
 
                                 if (!s2)
-                                        bb_error_msg_and_die("bad line %u", lineno);
+                                        bb_error_msg_and_die("bad line %u", parser.lineno);
 
                                 /* Correlate the position in the "@$*" with the delete
                                  * step so that we get the proper behavior:
@@ -255,12 +227,9 @@ static void make_device(char *path, int delete)
                         }
                         /* end of field parsing */
                         break; /* we found matching line, stop */
- next_line:
-                        free(line);
                 } /* end of "while line is read from /etc/mdev.conf" */
 
-                free(line); /* in case we used "break" to get here */
-                fclose(fp);
+                config_close(&parser);
         }
  end_parse: