| /* vi: set sw=4 ts=4: */ |
| /* |
| * mountpoint implementation for busybox |
| * |
| * Copyright (C) 2005 Bernhard Reutner-Fischer |
| * |
| * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
| * |
| * Based on sysvinit's mountpoint |
| */ |
| |
| //usage:#define mountpoint_trivial_usage |
| //usage: "[-q] <[-dn] DIR | -x DEVICE>" |
| //usage:#define mountpoint_full_usage "\n\n" |
| //usage: "Check if the directory is a mountpoint\n" |
| //usage: "\n -q Quiet" |
| //usage: "\n -d Print major/minor device number of the filesystem" |
| //usage: "\n -n Print device name of the filesystem" |
| //usage: "\n -x Print major/minor device number of the blockdevice" |
| //usage: |
| //usage:#define mountpoint_example_usage |
| //usage: "$ mountpoint /proc\n" |
| //usage: "/proc is not a mountpoint\n" |
| //usage: "$ mountpoint /sys\n" |
| //usage: "/sys is a mountpoint\n" |
| |
| #include "libbb.h" |
| |
| int mountpoint_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| int mountpoint_main(int argc UNUSED_PARAM, char **argv) |
| { |
| struct stat st; |
| const char *msg; |
| char *arg; |
| int rc, opt; |
| |
| opt_complementary = "=1"; /* must have one argument */ |
| opt = getopt32(argv, "qdxn"); |
| #define OPT_q (1) |
| #define OPT_d (2) |
| #define OPT_x (4) |
| #define OPT_n (8) |
| arg = argv[optind]; |
| msg = "%s"; |
| |
| rc = (opt & OPT_x) ? stat(arg, &st) : lstat(arg, &st); |
| if (rc != 0) |
| goto err; |
| |
| if (opt & OPT_x) { |
| if (S_ISBLK(st.st_mode)) { |
| printf("%u:%u\n", major(st.st_rdev), |
| minor(st.st_rdev)); |
| return EXIT_SUCCESS; |
| } |
| errno = 0; /* make perror_msg work as error_msg */ |
| msg = "%s: not a block device"; |
| goto err; |
| } |
| |
| errno = ENOTDIR; |
| if (S_ISDIR(st.st_mode)) { |
| dev_t st_dev = st.st_dev; |
| ino_t st_ino = st.st_ino; |
| char *p = xasprintf("%s/..", arg); |
| |
| if (stat(p, &st) == 0) { |
| //int is_mnt = (st_dev != st.st_dev) || (st_dev == st.st_dev && st_ino == st.st_ino); |
| int is_not_mnt = (st_dev == st.st_dev) && (st_ino != st.st_ino); |
| |
| if (opt & OPT_d) |
| printf("%u:%u\n", major(st_dev), minor(st_dev)); |
| if (opt & OPT_n) { |
| const char *d = find_block_device(arg); |
| /* name is undefined, but device is mounted -> anonymous superblock! */ |
| /* happens with btrfs */ |
| if (!d) { |
| d = "UNKNOWN"; |
| /* TODO: iterate /proc/mounts, or /proc/self/mountinfo |
| * to find out the device name */ |
| } |
| printf("%s %s\n", d, arg); |
| } |
| if (!(opt & (OPT_q | OPT_d | OPT_n))) |
| printf("%s is %sa mountpoint\n", arg, is_not_mnt ? "not " : ""); |
| return is_not_mnt; |
| } |
| arg = p; |
| /* else: stat had set errno, just fall through */ |
| } |
| |
| err: |
| if (!(opt & OPT_q)) |
| bb_perror_msg(msg, arg); |
| return EXIT_FAILURE; |
| } |