source: branches/3.2/mindi-busybox/miscutils/mountpoint.c @ 3232

Last change on this file since 3232 was 3232, checked in by bruno, 5 years ago
  • Update mindi-busybox to 1.21.1
File size: 2.6 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * mountpoint implementation for busybox
4 *
5 * Copyright (C) 2005 Bernhard Reutner-Fischer
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
8 *
9 * Based on sysvinit's mountpoint
10 */
11
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"
20//usage:
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"
26
27#include "libbb.h"
28
29int mountpoint_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
30int mountpoint_main(int argc UNUSED_PARAM, char **argv)
31{
32    struct stat st;
33    const char *msg;
34    char *arg;
35    int rc, opt;
36
37    opt_complementary = "=1"; /* must have one argument */
38    opt = getopt32(argv, "qdxn");
39#define OPT_q (1)
40#define OPT_d (2)
41#define OPT_x (4)
42#define OPT_n (8)
43    arg = argv[optind];
44    msg = "%s";
45
46    rc = (opt & OPT_x) ? stat(arg, &st) : lstat(arg, &st);
47    if (rc != 0)
48        goto err;
49
50    if (opt & OPT_x) {
51        if (S_ISBLK(st.st_mode)) {
52            printf("%u:%u\n", major(st.st_rdev),
53                        minor(st.st_rdev));
54            return EXIT_SUCCESS;
55        }
56        errno = 0; /* make perror_msg work as error_msg */
57        msg = "%s: not a block device";
58        goto err;
59    }
60
61    errno = ENOTDIR;
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);
66
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);
70
71            if (opt & OPT_d)
72                printf("%u:%u\n", major(st_dev), minor(st_dev));
73            if (opt & OPT_n) {
74                const char *d = find_block_device(arg);
75                /* name is undefined, but device is mounted -> anonymous superblock! */
76                /* happens with btrfs */
77                if (!d) {
78                    d = "UNKNOWN";
79                    /* TODO: iterate /proc/mounts, or /proc/self/mountinfo
80                     * to find out the device name */
81                }
82                printf("%s %s\n", d, arg);
83            }
84            if (!(opt & (OPT_q | OPT_d | OPT_n)))
85                printf("%s is %sa mountpoint\n", arg, is_not_mnt ? "not " : "");
86            return is_not_mnt;
87        }
88        arg = p;
89        /* else: stat had set errno, just fall through */
90    }
91
92 err:
93    if (!(opt & OPT_q))
94        bb_perror_msg(msg, arg);
95    return EXIT_FAILURE;
96}
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