1/* vi: set sw=4 ts=4: */
2/*
3 * mountpoint implementation for busybox
4 *
5 * Copyright (C) 2005 Bernhard Fischer
6 *
7 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
8 *
9 * Based on sysvinit's mountpoint
10 */
11
12#include "libbb.h"
13
14int mountpoint_main(int argc, char **argv);
15int mountpoint_main(int argc, char **argv)
16{
17	struct stat st;
18	char *arg;
19	int opt = getopt32(argv, "qdx");
20#define OPT_q (1)
21#define OPT_d (2)
22#define OPT_x (4)
23
24	if (optind != argc - 1)
25		bb_show_usage();
26
27	arg = argv[optind];
28
29	if ( (opt & OPT_x && stat(arg, &st) == 0) || (lstat(arg, &st) == 0) ) {
30		if (opt & OPT_x) {
31			if (S_ISBLK(st.st_mode)) {
32				printf("%u:%u\n", major(st.st_rdev),
33							minor(st.st_rdev));
34				return EXIT_SUCCESS;
35			} else {
36				if (opt & OPT_q)
37					putchar('\n');
38				else
39					bb_error_msg("%s: not a block device", arg);
40			}
41			return EXIT_FAILURE;
42		} else
43		if (S_ISDIR(st.st_mode)) {
44			dev_t st_dev = st.st_dev;
45			ino_t st_ino = st.st_ino;
46			char *p = xasprintf("%s/..", arg);
47
48			if (stat(p, &st) == 0) {
49				int ret = (st_dev != st.st_dev) ||
50					(st_dev == st.st_dev && st_ino == st.st_ino);
51				if (opt & OPT_d)
52					printf("%u:%u\n", major(st_dev), minor(st_dev));
53				else if (!(opt & OPT_q))
54					printf("%s is %sa mountpoint\n", arg, ret?"":"not ");
55				return !ret;
56			}
57		} else {
58			if (!(opt & OPT_q))
59				bb_error_msg("%s: not a directory", arg);
60			return EXIT_FAILURE;
61		}
62	}
63	if (!(opt & OPT_q))
64		bb_perror_msg("%s", arg);
65	return EXIT_FAILURE;
66}
67