source: MondoRescue/branches/3.2/mindi-busybox/util-linux/losetup.c@ 3232

/* vi: set sw=4 ts=4: */
/*
 * Mini losetup implementation for busybox
 *
 * Copyright (C) 2002  Matt Kraai.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

//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 "libbb.h"

int losetup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int losetup_main(int argc UNUSED_PARAM, char **argv)
{
    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;
}