unzip: make options parsing more robust on getopt w/o gnu extensions

Also, code shrank:

function                                             old     new   delta
static.extn                                           15      10      -5
packed_usage                                       29231   29217     -14
unzip_main                                          2388    2291     -97
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-116)           Total: -116 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 70 insertions, 67 deletions

diff --git a/archival/unzip.c b/archival/unzip.c
index c1b945a44..380674701 100644
--- a/archival/unzip.c
+++ b/archival/unzip.c
@@ -20,11 +20,11 @@
  */
 
 //usage:#define unzip_trivial_usage
-//usage:       "[-opts[modifiers]] FILE[.zip] [LIST] [-x XLIST] [-d DIR]"
+//usage:       "[-lnopq] FILE[.zip] [LIST] [-x XLIST] [-d DIR]"
 //usage:#define unzip_full_usage "\n\n"
 //usage:       "Extract files from ZIP archives\n"
 //usage:     "\n        -l      List archive contents (with -q for short form)"
-//usage:     "\n        -n      Never overwrite files (default)"
+//usage:     "\n        -n      Never overwrite files (default: ask)"
 //usage:     "\n        -o      Overwrite"
 //usage:     "\n        -p      Send output to stdout"
 //usage:     "\n        -q      Quiet"
@@ -277,6 +277,7 @@ int unzip_main(int argc, char **argv)
         IF_NOT_DESKTOP(const) smallint verbose = 0;
         smallint listing = 0;
         smallint overwrite = O_PROMPT;
+        smallint x_opt_seen;
 #if ENABLE_DESKTOP
         uint32_t cdf_offset;
 #endif
@@ -290,7 +291,6 @@ int unzip_main(int argc, char **argv)
         llist_t *zreject = NULL;
         char *base_dir = NULL;
         int i, opt;
-        int opt_range = 0;
         char key_buf[80];
         struct stat stat_buf;
 
@@ -335,81 +335,81 @@ int unzip_main(int argc, char **argv)
  *    204372                   1 file
  */
 
+        x_opt_seen = 0;
         /* '-' makes getopt return 1 for non-options */
         while ((opt = getopt(argc, argv, "-d:lnopqxv")) != -1) {
-                switch (opt_range) {
-                case 0: /* Options */
-                        switch (opt) {
-                        case 'l': /* List */
-                                listing = 1;
-                                break;
+                switch (opt) {
+                case 'd':  /* Extract to base directory */
+                        base_dir = optarg;
+                        break;
 
-                        case 'n': /* Never overwrite existing files */
-                                overwrite = O_NEVER;
-                                break;
+                case 'l': /* List */
+                        listing = 1;
+                        break;
 
-                        case 'o': /* Always overwrite existing files */
-                                overwrite = O_ALWAYS;
-                                break;
+                case 'n': /* Never overwrite existing files */
+                        overwrite = O_NEVER;
+                        break;
 
-                        case 'p': /* Extract files to stdout and fall through to set verbosity */
-                                dst_fd = STDOUT_FILENO;
+                case 'o': /* Always overwrite existing files */
+                        overwrite = O_ALWAYS;
+                        break;
 
-                        case 'q': /* Be quiet */
-                                quiet++;
-                                break;
+                case 'p': /* Extract files to stdout and fall through to set verbosity */
+                        dst_fd = STDOUT_FILENO;
 
-                        case 'v': /* Verbose list */
-                                IF_DESKTOP(verbose++;)
-                                listing = 1;
-                                break;
+                case 'q': /* Be quiet */
+                        quiet++;
+                        break;
 
-                        case 1: /* The zip file */
-                                /* +5: space for ".zip" and NUL */
-                                src_fn = xmalloc(strlen(optarg) + 5);
-                                strcpy(src_fn, optarg);
-                                opt_range++;
-                                break;
+                case 'v': /* Verbose list */
+                        IF_DESKTOP(verbose++;)
+                        listing = 1;
+                        break;
 
-                        default:
-                                bb_show_usage();
-                        }
+                case 'x':
+                        x_opt_seen = 1;
                         break;
 
-                case 1: /* Include files */
-                        if (opt == 1) {
+                case 1:
+                        if (!src_fn) {
+                                /* The zip file */
+                                /* +5: space for ".zip" and NUL */
+                                src_fn = xmalloc(strlen(optarg) + 5);
+                                strcpy(src_fn, optarg);
+                        } else if (!x_opt_seen) {
+                                /* Include files */
                                 llist_add_to(&zaccept, optarg);
-                                break;
-                        }
-                        if (opt == 'd') {
-                                base_dir = optarg;
-                                opt_range += 2;
-                                break;
-                        }
-                        if (opt == 'x') {
-                                opt_range++;
-                                break;
-                        }
-                        bb_show_usage();
-
-                case 2 : /* Exclude files */
-                        if (opt == 1) {
+                        } else {
+                                /* Exclude files */
                                 llist_add_to(&zreject, optarg);
-                                break;
                         }
-                        if (opt == 'd') { /* Extract to base directory */
-                                base_dir = optarg;
-                                opt_range++;
-                                break;
-                        }
-                        /* fall through */
+                        break;
 
                 default:
                         bb_show_usage();
                 }
         }
 
-        if (src_fn == NULL) {
+#ifndef __GLIBC__
+        /*
+         * This code is needed for non-GNU getopt
+         * which doesn't understand "-" in option string.
+         * The -x option won't work properly in this case:
+         * "unzip a.zip q -x w e" will be interpreted as
+         * "unzip a.zip q w e -x" = "unzip a.zip q w e"
+         */
+        argv += optind;
+        if (argv[0]) {
+                /* +5: space for ".zip" and NUL */
+                src_fn = xmalloc(strlen(argv[0]) + 5);
+                strcpy(src_fn, argv[0]);
+                while (*++argv)
+                        llist_add_to(&zaccept, *argv);
+        }
+#endif
+
+        if (!src_fn) {
                 bb_show_usage();
         }
 
@@ -420,17 +420,20 @@ int unzip_main(int argc, char **argv)
                 if (overwrite == O_PROMPT)
                         overwrite = O_NEVER;
         } else {
-                static const char extn[][5] = {"", ".zip", ".ZIP"};
-                int orig_src_fn_len = strlen(src_fn);
-                int src_fd = -1;
+                static const char extn[][5] = { ".zip", ".ZIP" };
+                char *ext = src_fn + strlen(src_fn);
+                int src_fd;
 
-                for (i = 0; (i < 3) && (src_fd == -1); i++) {
-                        strcpy(src_fn + orig_src_fn_len, extn[i]);
+                i = 0;
+                for (;;) {
                         src_fd = open(src_fn, O_RDONLY);
-                }
-                if (src_fd == -1) {
-                        src_fn[orig_src_fn_len] = '\0';
-                        bb_error_msg_and_die("can't open %s, %s.zip, %s.ZIP", src_fn, src_fn, src_fn);
+                        if (src_fd >= 0)
+                                break;
+                        if (++i > 2) {
+                                *ext = '\0';
+                                bb_error_msg_and_die("can't open %s[.zip]", src_fn);
+                        }
+                        strcpy(ext, extn[i - 1]);
                 }
                 xmove_fd(src_fd, zip_fd);
         }