Make config file parsing (mostly) compatible with the Python implementation

[browser-switch] / main.c

diff --git a/main.c b/main.c
index ec1a042..5429a59 100644 (file)
--- a/main.c
+++ b/main.c
@@ -27,6 +27,7 @@
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <regex.h>
 #include <dbus/dbus-glib.h>
 
 #include "browser-switchboard.h"
@@ -54,14 +55,14 @@ static void waitforzombies(int signalnum) {
 }
 
 static void read_config(int signalnum) {
-       char * homedir;
-       char * configfile;
+       char *homedir, *configfile;
        size_t len;
        char buf[MAXLINE];
-       char * tmp;
-       char * value;
-       char * default_browser = NULL;
-       FILE * fp;
+       char *key, *value;
+       char *default_browser = NULL;
+       FILE *fp;
+       regex_t re_ignore, re_config1, re_config2;
+       regmatch_t substrs[3];
 
        set_config_defaults(&ctx);
 
@@ -76,36 +77,64 @@ static void read_config(int signalnum) {
        if (!(fp = fopen(configfile, "r")))
                goto out_noopen;
 
+       /* compile regex matching blank lines or comments */
+       if (regcomp(&re_ignore, "^[[:space:]]*(#|$)", REG_EXTENDED|REG_NOSUB))
+               goto out_nore;
+       /* compile regex matching foo = "bar", with arbitrary whitespace at
+          beginning and end of line and surrounding the = */
+       if (regcomp(&re_config1,
+                   "^[[:space:]]*([^=[:space:]]+)[[:space:]]*=[[:space:]]*\"(.*)\"[[:space:]]*$",
+                   REG_EXTENDED)) {
+               regfree(&re_ignore);
+               goto out_nore;
+       }
+       /* compile regex matching foo = bar, with arbitrary whitespace at
+          beginning of line and surrounding the = */
+       if (regcomp(&re_config2,
+                   "^[[:space:]]*([^=[:space:]]+)[[:space:]]*=[[:space:]]*(.*)$",
+                   REG_EXTENDED|REG_NEWLINE)) {
+               regfree(&re_ignore);
+               regfree(&re_config1);
+               goto out_nore;
+       }
+
        /* Read in the config file one line at a time and parse it
           XXX doesn't deal with lines longer than MAXLINE */
        while (fgets(buf, MAXLINE, fp)) {
-               /* skip comments */
-               if (buf[0] == '#')
+               printf("%s", buf);
+               /* skip blank lines and comments */
+               if (!regexec(&re_ignore, buf, 0, NULL, 0))
                        continue;
-               /* look for the = in the line */
-               if (!(tmp = strchr(buf, '=')))
+
+               /* Find the substrings corresponding to the key and value
+                  If the line doesn't match our idea of a config file entry,
+                  skip it */
+               if (regexec(&re_config1, buf, 3, substrs, 0) &&
+                   regexec(&re_config2, buf, 3, substrs, 0))
+                       continue;
+               if (substrs[1].rm_so == -1 || substrs[2].rm_so == -1)
                        continue;
 
-               /* split the line into parameter (before =, in buf) and
-                  value (after =, in value) */
-               if (!(value = calloc(strlen(tmp+1)+1, sizeof(char))))
+               /* copy the config value into a new string */
+               len = substrs[2].rm_eo - substrs[2].rm_so;
+               if (!(value = calloc(len+1, sizeof(char))))
                        goto out;
-               strncpy(value, tmp+1, strlen(tmp+1));
-               value[strlen(tmp+1)] = '\0';
-               /* scribble over the = in buf with a \0 -- that makes buf
-                  just the parameter name */
-               *tmp = '\0';
-               /* if we find a newline in value, replace that with a \0 too */
-               if ((tmp = strchr(value, '\n')))
-                       *tmp = '\0';
-
-               if (!strcmp(buf, "continuous_mode")) {
+               strncpy(value, buf+substrs[2].rm_so, len);
+               /* calloc() zeroes the memory, so string is automatically
+                  null terminated */
+
+               /* make key point to a null-terminated string holding the 
+                  config key */
+               key = buf + substrs[1].rm_so;
+               buf[substrs[1].rm_eo] = '\0';
+
+               if (!strcmp(key, "continuous_mode")) {
                        ctx.continuous_mode = atoi(value);
                        free(value);
-               } else if (!strcmp(buf, "default_browser")) {
+               } else if (!strcmp(key, "default_browser")) {
                        if (!default_browser)
                                default_browser = value;
-               } else if (!strcmp(buf, "other_browser_cmd")) {
+               } else if (!strcmp(key, "other_browser_cmd")) {
                        if (!ctx.other_browser_cmd)
                                ctx.other_browser_cmd = value;
                } else {
@@ -120,6 +149,10 @@ static void read_config(int signalnum) {
        printf("other_browser_cmd: '%s'\n", ctx.other_browser_cmd?ctx.other_browser_cmd:"NULL");
 
 out:
+       regfree(&re_ignore);
+       regfree(&re_config1);
+       regfree(&re_config2);
+out_nore:
        fclose(fp);
 out_noopen:
        update_default_browser(&ctx, default_browser);