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-rw-r--r--util-linux/mountpoint.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/util-linux/mountpoint.c b/util-linux/mountpoint.c
new file mode 100644
index 0000000..8b9e1d7
--- /dev/null
+++ b/util-linux/mountpoint.c
@@ -0,0 +1,105 @@
+/* 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
+ */
+//config:config MOUNTPOINT
+//config: bool "mountpoint"
+//config: default y
+//config: help
+//config: mountpoint checks if the directory is a mountpoint.
+
+//applet:IF_MOUNTPOINT(APPLET(mountpoint, BB_DIR_BIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_MOUNTPOINT) += mountpoint.o
+
+//usage:#define mountpoint_trivial_usage
+//usage: "[-q] <[-dn] DIR | -x DEVICE>"
+//usage:#define mountpoint_full_usage "\n\n"
+//usage: "Check if the directory is a mountpoint\n"
+//usage: "\n -q Quiet"
+//usage: "\n -d Print major/minor device number of the filesystem"
+//usage: "\n -n Print device name of the filesystem"
+//usage: "\n -x Print major/minor device number of the blockdevice"
+//usage:
+//usage:#define mountpoint_example_usage
+//usage: "$ 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;
+}