1 /* vi: set sw=4 ts=4: */
3 * mountpoint implementation for busybox
5 * Copyright (C) 2005 Bernhard Reutner-Fischer
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
9 * Based on sysvinit's mountpoint
12 //usage:#define mountpoint_trivial_usage
13 //usage: "[-q] <[-dn] DIR | -x DEVICE>"
14 //usage:#define mountpoint_full_usage "\n\n"
15 //usage: "Check if the directory is a mountpoint\n"
16 //usage: "\n -q Quiet"
17 //usage: "\n -d Print major/minor device number of the filesystem"
18 //usage: "\n -n Print device name of the filesystem"
19 //usage: "\n -x Print major/minor device number of the blockdevice"
21 //usage:#define mountpoint_example_usage
22 //usage: "$ mountpoint /proc\n"
23 //usage: "/proc is not a mountpoint\n"
24 //usage: "$ mountpoint /sys\n"
25 //usage: "/sys is a mountpoint\n"
29 int mountpoint_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
30 int mountpoint_main(int argc UNUSED_PARAM, char **argv)
37 opt_complementary = "=1"; /* must have one argument */
38 opt = getopt32(argv, "qdxn");
46 rc = (opt & OPT_x) ? stat(arg, &st) : lstat(arg, &st);
51 if (S_ISBLK(st.st_mode)) {
52 printf("%u:%u\n", major(st.st_rdev),
56 errno = 0; /* make perror_msg work as error_msg */
57 msg = "%s: not a block device";
62 if (S_ISDIR(st.st_mode)) {
63 dev_t st_dev = st.st_dev;
64 ino_t st_ino = st.st_ino;
65 char *p = xasprintf("%s/..", arg);
67 if (stat(p, &st) == 0) {
68 //int is_mnt = (st_dev != st.st_dev) || (st_dev == st.st_dev && st_ino == st.st_ino);
69 int is_not_mnt = (st_dev == st.st_dev) && (st_ino != st.st_ino);
72 printf("%u:%u\n", major(st_dev), minor(st_dev));
74 const char *d = find_block_device(arg);
75 /* name is undefined, but device is mounted -> anonymous superblock! */
76 /* happens with btrfs */
79 /* TODO: iterate /proc/mounts, or /proc/self/mountinfo
80 * to find out the device name */
82 printf("%s %s\n", d, arg);
84 if (!(opt & (OPT_q | OPT_d | OPT_n)))
85 printf("%s is %sa mountpoint\n", arg, is_not_mnt ? "not " : "");
89 /* else: stat had set errno, just fall through */
94 bb_perror_msg(msg, arg);