LXR busybox/util-linux/losetup.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * Mini losetup implementation for busybox
   4 *
   5 * Copyright (C) 2002  Matt Kraai.
   6 *
   7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   8 */
   9
  10#include "libbb.h"
  11
  12int losetup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  13int losetup_main(int argc, char **argv)
  14{
  15        char dev[] = LOOP_NAME"0";
  16        unsigned opt;
  17        char *opt_o;
  18        char *s;
  19        unsigned long long offset = 0;
  20
  21        /* max 2 args, all opts are mutually exclusive */
  22        opt_complementary = "?2:d--of:o--df:f-do";
  23        opt = getopt32(argv, "do:f", &opt_o);
  24        argc -= optind;
  25        argv += optind;
  26
  27        if (opt == 0x2) // -o
  28                offset = xatoull(opt_o);
  29
  30        if (opt == 0x4 && argc) // -f does not take any argument
  31                bb_show_usage();
  32
  33        if (opt == 0x1) { // -d
  34                /* detach takes exactly one argument */
  35                if (argc != 1)
  36                        bb_show_usage();
  37                if (del_loop(argv[0]))
  38                        bb_simple_perror_msg_and_die(argv[0]);
  39                return EXIT_SUCCESS;
  40        }
  41
  42        if (argc == 2) {
  43                /* -o or no option */
  44                if (set_loop(&argv[0], argv[1], offset) < 0)
  45                        bb_simple_perror_msg_and_die(argv[0]);
  46                return EXIT_SUCCESS;
  47        }
  48
  49        if (argc == 1) {
  50                /* -o or no option */
  51                s = query_loop(argv[0]);
  52                if (!s)
  53                        bb_simple_perror_msg_and_die(argv[0]);
  54                printf("%s: %s\n", argv[0], s);
  55                if (ENABLE_FEATURE_CLEAN_UP)
  56                        free(s);
  57                return EXIT_SUCCESS;
  58        }
  59
  60        /* -o, -f or no option */
  61        while (1) {
  62                s = query_loop(dev);
  63                if (!s) {
  64                        if (opt == 0x4) {
  65                                puts(dev);
  66                                return EXIT_SUCCESS;
  67                        }
  68                } else {
  69                        if (opt != 0x4)
  70                                printf("%s: %s\n", dev, s);
  71                        if (ENABLE_FEATURE_CLEAN_UP)
  72                                free(s);
  73                }
  74
  75                if (++dev[sizeof(dev) - 2] > '9')
  76                        break;
  77        }
  78        return EXIT_SUCCESS;
  79}
  80