blob: 98e1d3096b89d5d2ed7fa0cf439fde3814a13ed4 [file] [log] [blame]
/* mountpoint.c - Check if a directory is a mountpoint.
* Copyright 2012 Elie De Brauwer <>
USE_MOUNTPOINT(NEWTOY(mountpoint, "<1qdx[-dx]", TOYFLAG_BIN))
bool "mountpoint"
default y
usage: mountpoint [-q] [-d] directory
mountpoint [-q] [-x] device
-q Be quiet, return zero if directory is a mountpoint
-d Print major/minor device number of the directory
-x Print major/minor device number of the block device
#define FOR_mountpoint
#include "toys.h"
static void die(char *gripe)
if (!(toys.optflags & FLAG_q)) printf("%s: not a %s\n", *toys.optargs, gripe);
void mountpoint_main(void)
struct stat st1, st2;
char *arg = *toys.optargs;
int quiet = toys.optflags & FLAG_q;
if (lstat(arg, &st1)) perror_exit_raw(arg);
if (toys.optflags & FLAG_x) {
if (S_ISBLK(st1.st_mode)) {
if (!quiet)
printf("%u:%u\n", dev_major(st1.st_rdev), dev_minor(st1.st_rdev));
die("block device");
// TODO: Ignore the fact a file can be a mountpoint for --bind mounts.
if (!S_ISDIR(st1.st_mode)) die("directory");
arg = xmprintf("%s/..", arg);
xstat(arg, &st2);
if (CFG_TOYBOX_FREE) free(arg);
// If the device is different, it's a mount point. If the device _and_
// inode are the same, it's probably "/". This misses --bind mounts from
// elsewhere in the same filesystem, but so does the other one and in the
// absence of a spec I guess that's the expected behavior?
toys.exitval = !(st1.st_dev != st2.st_dev || st1.st_ino == st2.st_ino);
if (toys.optflags & FLAG_d)
printf("%u:%u\n", dev_major(st1.st_dev), dev_minor(st1.st_dev));
else if (!quiet)
printf("%s is %sa mountpoint\n", *toys.optargs, toys.exitval ? "not " : "");