hush/util-linux/losetup.c

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/* 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;
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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) {
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puts(dev);
return EXIT_SUCCESS;
}
} else {
if (opt != OPT_f)
printf("%s: %s\n", dev, s);
if (ENABLE_FEATURE_CLEAN_UP)
free(s);
}
}
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return EXIT_SUCCESS;
}