hush: make getopt32 usable in builtins. use it in unset.

 more uses are expected in the future.

function                                             old     new   delta
getopt32                                            1356    1393     +37
builtin_export                                       256     266     +10
builtin_unset                                        418     380     -38

3 files changed, 42 insertions, 36 deletions

diff --git a/libbb/getopt32.c b/libbb/getopt32.c
index 5190fa61a..1eb868c97 100644
--- a/libbb/getopt32.c
+++ b/libbb/getopt32.c
@@ -72,6 +72,9 @@ getopt32(char **argv, const char *applet_opts, ...)
         env -i ls -d /
         Here we want env to process just the '-i', not the '-d'.
 
+ "!"    Report bad option, missing required options,
+        inconsistent options with all-ones return value (instead of abort).
+
 const char *applet_long_options
 
         This struct allows you to define long options:
@@ -327,6 +330,7 @@ getopt32(char **argv, const char *applet_opts, ...)
         unsigned flags = 0;
         unsigned requires = 0;
         t_complementary complementary[33]; /* last stays zero-filled */
+        char first_char;
         int c;
         const unsigned char *s;
         t_complementary *on_off;
@@ -357,6 +361,11 @@ getopt32(char **argv, const char *applet_opts, ...)
         on_off = complementary;
         memset(on_off, 0, sizeof(complementary));
 
+        /* skip bbox extension */
+        first_char = applet_opts[0];
+        if (first_char == '!')
+                applet_opts++;
+
         /* skip GNU extension */
         s = (const unsigned char *)applet_opts;
         if (*s == '+' || *s == '-')
@@ -549,11 +558,11 @@ getopt32(char **argv, const char *applet_opts, ...)
                          * is always NULL (see above) */
                         if (on_off->opt_char == '\0' /* && c != '\0' */) {
                                 /* c is probably '?' - "bad option" */
-                                bb_show_usage();
+                                goto error;
                         }
                 }
                 if (flags & on_off->incongruously)
-                        bb_show_usage();
+                        goto error;
                 trigger = on_off->switch_on & on_off->switch_off;
                 flags &= ~(on_off->switch_off ^ trigger);
                 flags |= on_off->switch_on ^ trigger;
@@ -577,16 +586,24 @@ getopt32(char **argv, const char *applet_opts, ...)
 
         /* check depending requires for given options */
         for (on_off = complementary; on_off->opt_char; on_off++) {
-                if (on_off->requires && (flags & on_off->switch_on) &&
-                                        (flags & on_off->requires) == 0)
-                        bb_show_usage();
+                if (on_off->requires
+                 && (flags & on_off->switch_on)
+                 && (flags & on_off->requires) == 0
+                ) {
+                        goto error;
+                }
         }
         if (requires && (flags & requires) == 0)
-                bb_show_usage();
+                goto error;
         argc -= optind;
         if (argc < min_arg || (max_arg >= 0 && argc > max_arg))
-                bb_show_usage();
+                goto error;
 
         option_mask32 = flags;
         return flags;
+
+ error:
+        if (first_char != '!')
+                bb_show_usage();
+        return (int32_t)-1;
 }
diff --git a/shell/hush.c b/shell/hush.c
index 292b8b2e3..d0819f691 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -6451,7 +6451,11 @@ static int builtin_export(char **argv)
         }
 
 #if ENABLE_HUSH_EXPORT_N
-        opt_unexport = getopt32(argv, "+n"); /* "+": stop at 1st non-option */
+        /* "!": do not abort on errors */
+        /* "+": stop at 1st non-option */
+        opt_unexport = getopt32(argv, "!+n");
+        if (opt_unexport == (unsigned)-1)
+                return EXIT_FAILURE;
         argv += optind;
 #else
         opt_unexport = 0;
@@ -6918,36 +6922,22 @@ static int builtin_umask(char **argv)
 static int builtin_unset(char **argv)
 {
         int ret;
-        char var;
-        char *arg;
-
-        if (!*++argv)
-                return EXIT_SUCCESS;
+        unsigned opts;
 
-        var = 0;
-        while ((arg = *argv) != NULL && arg[0] == '-') {
-                arg++;
-                do {
-                        switch (*arg) {
-                        case 'v':
-                        case 'f':
-                                if (var == 0 || var == *arg) {
-                                        var = *arg;
-                                        break;
-                                }
-                                /* else: unset -vf, which is illegal.
-                                 * fall through */
-                        default:
-                                bb_error_msg("unset: %s: invalid option", *argv);
-                                return EXIT_FAILURE;
-                        }
-                } while (*++arg);
-                argv++;
+        /* "!": do not abort on errors */
+        /* "+": stop at 1st non-option */
+        opts = getopt32(argv, "!+vf");
+        if (opts == (unsigned)-1)
+                return EXIT_FAILURE;
+        if (opts == 3) {
+                bb_error_msg("unset: -v and -f are exclusive");
+                return EXIT_FAILURE;
         }
+        argv += optind;
 
         ret = EXIT_SUCCESS;
         while (*argv) {
-                if (var != 'f') {
+                if (!(opts & 2)) { /* not -f */
                         if (unset_local_var(*argv)) {
                                 /* unset <nonexistent_var> doesn't fail.
                                  * Error is when one tries to unset RO var.
diff --git a/shell/hush_test/hush-vars/unset.right b/shell/hush_test/hush-vars/unset.right
index 8dea7c40d..1fbe76a73 100644
--- a/shell/hush_test/hush-vars/unset.right
+++ b/shell/hush_test/hush-vars/unset.right
@@ -1,6 +1,5 @@
-hush: unset: -: invalid option
-1
-hush: unset: -m: invalid option
+0
+unset: invalid option -- m
 1
 0
 ___