1/* Utilities for reading/writing fstab, mtab, etc.
2 Copyright (C) 1995-2026 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#ifndef _MNTENT_H
20#define _MNTENT_H 1
21
22#include <features.h>
23#include <paths.h>
24#include <bits/types/FILE.h>
25
26/* File listing canonical interesting mount points. */
27#define MNTTAB _PATH_MNTTAB /* Deprecated alias. */
28
29/* File listing currently active mount points. */
30#define MOUNTED _PATH_MOUNTED /* Deprecated alias. */
31
32
33/* General filesystem types. */
34#define MNTTYPE_IGNORE "ignore" /* Ignore this entry. */
35#define MNTTYPE_NFS "nfs" /* Network file system. */
36#define MNTTYPE_SWAP "swap" /* Swap device. */
37
38
39/* Generic mount options. */
40#define MNTOPT_DEFAULTS "defaults" /* Use all default options. */
41#define MNTOPT_RO "ro" /* Read only. */
42#define MNTOPT_RW "rw" /* Read/write. */
43#define MNTOPT_SUID "suid" /* Set uid allowed. */
44#define MNTOPT_NOSUID "nosuid" /* No set uid allowed. */
45#define MNTOPT_NOAUTO "noauto" /* Do not auto mount. */
46
47
48__BEGIN_DECLS
49
50/* Structure describing a mount table entry. */
51struct mntent
52 {
53 char *mnt_fsname; /* Device or server for filesystem. */
54 char *mnt_dir; /* Directory mounted on. */
55 char *mnt_type; /* Type of filesystem: ufs, nfs, etc. */
56 char *mnt_opts; /* Comma-separated options for fs. */
57 int mnt_freq; /* Dump frequency (in days). */
58 int mnt_passno; /* Pass number for `fsck'. */
59 };
60
61
62/* Prepare to begin reading and/or writing mount table entries from the
63 beginning of FILE. MODE is as for `fopen'. */
64extern FILE *setmntent (const char *__file, const char *__mode) __THROW;
65
66/* Read one mount table entry from STREAM. Returns a pointer to storage
67 reused on the next call, or null for EOF or error (use feof/ferror to
68 check). */
69extern struct mntent *getmntent (FILE *__stream) __THROW;
70
71#ifdef __USE_MISC
72/* Reentrant version of the above function. */
73extern struct mntent *getmntent_r (FILE *__restrict __stream,
74 struct mntent *__restrict __result,
75 char *__restrict __buffer,
76 int __bufsize) __THROW;
77#endif
78
79/* Write the mount table entry described by MNT to STREAM.
80 Return zero on success, nonzero on failure. */
81extern int addmntent (FILE *__restrict __stream,
82 const struct mntent *__restrict __mnt) __THROW;
83
84/* Close a stream opened with `setmntent'. */
85extern int endmntent (FILE *__stream) __THROW;
86
87/* Search MNT->mnt_opts for an option matching OPT.
88 Returns the address of the substring, or null if none found. */
89extern char *hasmntopt (const struct mntent *__mnt,
90 const char *__opt) __THROW;
91
92
93__END_DECLS
94
95#endif /* mntent.h */