getopt32 must remain NOFORK-safe (no mallocs!). Using alloca and pretending

stack is infinite. Unfortunately, +79 bytes.

diff --git a/libbb/getopt32.c b/libbb/getopt32.c
index e5d97e98c59b5e93fa6a2683bf245b8efbcab87a..25eb113df109e3848f9c65e6be928e0b9c738662 100644 (file)
--- a/libbb/getopt32.c
+++ b/libbb/getopt32.c
@@ -307,7 +307,7 @@ getopt32(int argc, char **argv, const char *applet_opts, ...)
        va_list p;
 #if ENABLE_GETOPT_LONG
        const struct option *l_o;
-       struct option *long_options = NULL;
+       struct option *long_options = (struct option *) &bb_null_long_options;
 #endif
        unsigned trigger;
        char **pargv = NULL;
@@ -350,11 +350,11 @@ getopt32(int argc, char **argv, const char *applet_opts, ...)
                count = 1;
                optstr = applet_long_options;
                while (optstr[0]) {
-                       optstr += strlen(optstr) + 3; /* skip \0, has_arg, val */
+                       optstr += strlen(optstr) + 3; /* skip NUL, has_arg, val */
                        count++;
                }
                /* count == no. of longopts + 1 */
-               long_options = xzalloc(count * sizeof(*long_options));
+               long_options = alloca(count * sizeof(*long_options));
                i = 0;
                optstr = applet_long_options;
                while (--count) {
@@ -476,7 +476,7 @@ getopt32(int argc, char **argv, const char *applet_opts, ...)
         * (supposed to act as --header, but doesn't) */
 #if ENABLE_GETOPT_LONG
        while ((c = getopt_long(argc, argv, applet_opts,
-                       long_options ? long_options : bb_null_long_options, NULL)) != -1) {
+                       long_options, NULL)) != -1) {
 #else
        while ((c = getopt(argc, argv, applet_opts)) != -1) {
 #endif
@@ -535,9 +535,6 @@ getopt32(int argc, char **argv, const char *applet_opts, ...)
        if (argc < min_arg || (max_arg >= 0 && argc > max_arg))
                bb_show_usage();
 
-#if ENABLE_GETOPT_LONG
-       free(long_options);
-#endif
        option_mask32 = flags;
        return flags;
 }