vi: fix [end] key handling
[oweals/busybox.git] / util-linux / losetup.c
index c94456522e8bf9d908a74f0fa7133b6c3d56356b..21108d0bfb372fced9e0925ebd1a0037b12c21d4 100644 (file)
+/* vi: set sw=4 ts=4: */
 /*
  * Mini losetup implementation for busybox
  *
  * Copyright (C) 2002  Matt Kraai.
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
-#include <getopt.h>
-#include <stdlib.h>
+//usage:#define losetup_trivial_usage
+//usage:       "[-r] [-o OFS] LOOPDEV FILE - associate loop devices\n"
+//usage:       "       losetup -d LOOPDEV - disassociate\n"
+//usage:       "       losetup [-f] - show"
+//usage:#define losetup_full_usage "\n\n"
+//usage:       "       -o OFS  Start OFS bytes into FILE"
+//usage:     "\n       -r      Read-only"
+//usage:     "\n       -f      Show first free loop device"
+//usage:
+//usage:#define losetup_notes_usage
+//usage:       "No arguments will display all current associations.\n"
+//usage:       "One argument (losetup /dev/loop1) will display the current association\n"
+//usage:       "(if any), or disassociate it (with -d). The display shows the offset\n"
+//usage:       "and filename of the file the loop device is currently bound to.\n\n"
+//usage:       "Two arguments (losetup /dev/loop1 file.img) create a new association,\n"
+//usage:       "with an optional offset (-o 12345). Encryption is not yet supported.\n"
+//usage:       "losetup -f will show the first loop free loop device\n\n"
 
-#include "busybox.h"
+#include "libbb.h"
 
-int
-losetup_main (int argc, char **argv)
+int losetup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int losetup_main(int argc UNUSED_PARAM, char **argv)
 {
-  int delete = 0;
-  int offset = 0;
-  int opt;
-
-  while ((opt = getopt (argc, argv, "do:")) != -1)
-    switch (opt)
-      {
-      case 'd':
-       delete = 1;
-       break;
-
-      case 'o':
-       offset = bb_xparse_number (optarg, NULL);
-       break;
-
-      default:
-       bb_show_usage();
-      }
-
-  if ((delete && (offset || optind + 1 != argc))
-      || (!delete && optind + 2 != argc))
-    bb_show_usage();
-
-  opt = 0;
-  if (delete)
-    return del_loop (argv[optind]) ? EXIT_SUCCESS : EXIT_FAILURE;
-  else
-    return set_loop (argv[optind], argv[optind + 1], offset, &opt)
-      ? EXIT_FAILURE : EXIT_SUCCESS;
+       unsigned opt;
+       int n;
+       char *opt_o;
+       unsigned long long offset = 0;
+       enum {
+               OPT_d = (1 << 0),
+               OPT_o = (1 << 1),
+               OPT_f = (1 << 2),
+               OPT_r = (1 << 3), /* must be last */
+       };
+
+       /* max 2 args, -d,-o,-f opts are mutually exclusive */
+       opt_complementary = "?2:d--of:o--df:f--do";
+       opt = getopt32(argv, "do:fr", &opt_o);
+       argv += optind;
+
+       if (opt == OPT_o)
+               offset = xatoull(opt_o);
+
+       if (opt == OPT_d) {
+               /* -d BLOCKDEV */
+               if (!argv[0] || argv[1])
+                       bb_show_usage();
+               if (del_loop(argv[0]))
+                       bb_simple_perror_msg_and_die(argv[0]);
+               return EXIT_SUCCESS;
+       }
+
+       if (argv[0]) {
+               char *s;
+
+               if (opt == OPT_f) /* -f should not have arguments */
+                       bb_show_usage();
+
+               if (argv[1]) {
+                       /* [-r] [-o OFS] BLOCKDEV FILE */
+                       if (set_loop(&argv[0], argv[1], offset, (opt / OPT_r)) < 0)
+                               bb_simple_perror_msg_and_die(argv[0]);
+                       return EXIT_SUCCESS;
+               }
+               /* [-r] [-o OFS] BLOCKDEV */
+               s = query_loop(argv[0]);
+               if (!s)
+                       bb_simple_perror_msg_and_die(argv[0]);
+               printf("%s: %s\n", argv[0], s);
+               if (ENABLE_FEATURE_CLEAN_UP)
+                       free(s);
+               return EXIT_SUCCESS;
+       }
+
+       /* [-r] [-o OFS|-f] with no params */
+       n = 0;
+       while (1) {
+               char *s;
+               char dev[LOOP_NAMESIZE];
+
+               sprintf(dev, LOOP_FORMAT, n);
+               s = query_loop(dev);
+               n++;
+               if (!s) {
+                       if (n > 9 && errno && errno != ENXIO)
+                               return EXIT_SUCCESS;
+                       if (opt == OPT_f) {
+                               puts(dev);
+                               return EXIT_SUCCESS;
+                       }
+               } else {
+                       if (opt != OPT_f)
+                               printf("%s: %s\n", dev, s);
+                       if (ENABLE_FEATURE_CLEAN_UP)
+                               free(s);
+               }
+       }
+       return EXIT_SUCCESS;
 }