1GETFSENT(3) Linux Programmer's Manual GETFSENT(3)
2
6 getfsent, getfsspec, getfsfile, setfsent, endfsent - handle fstab en‐
7 tries
8
10 #include <fstab.h>
11 int setfsent(void);
13 struct fstab *getfsent(void);
14 void endfsent(void);
15 struct fstab *getfsfile(const char *mount_point);
17 struct fstab *getfsspec(const char *special_file);
18
20 These functions read from the file /etc/fstab. The struct fstab is de‐
21 fined by:
22 struct fstab {
24 char *fs_spec; /* block device name */
25 char *fs_file; /* mount point */
26 char *fs_vfstype; /* filesystem type */
27 char *fs_mntops; /* mount options */
28 const char *fs_type; /* rw/rq/ro/sw/xx option */
29 int fs_freq; /* dump frequency, in days */
30 int fs_passno; /* pass number on parallel dump */
31 };
32 Here the field fs_type contains (on a *BSD system) one of the five
34 strings "rw", "rq", "ro", "sw", "xx" (read-write, read-write with
35 quota, read-only, swap, ignore).
36 The function setfsent() opens the file when required and positions it
38 at the first line.
39 The function getfsent() parses the next line from the file. (After
41 opening it when required.)
42 The function endfsent() closes the file when required.
44 The function getfsspec() searches the file from the start and returns
46 the first entry found for which the fs_spec field matches the spe‐
47 cial_file argument.
48 The function getfsfile() searches the file from the start and returns
50 the first entry found for which the fs_file field matches the
51 mount_point argument.
52
54 Upon success, the functions getfsent(), getfsfile(), and getfsspec()
55 return a pointer to a struct fstab, while setfsent() returns 1. Upon
56 failure or end-of-file, these functions return NULL and 0, respec‐
57 tively.
58
60 For an explanation of the terms used in this section, see at‐
61 tributes(7).
62 ┌─────────────┬───────────────┬────────────────────────────────────────┐
64 │Interface │ Attribute │ Value │
65 ├─────────────┼───────────────┼────────────────────────────────────────┤
66 │endfsent(), │ Thread safety │ MT-Unsafe race:fsent │
67 │setfsent() │ │ │
68 ├─────────────┼───────────────┼────────────────────────────────────────┤
69 │getfsent(), │ Thread safety │ MT-Unsafe race:fsent locale │
70 │getfsspec(), │ │ │
71 │getfsfile() │ │ │
72 └─────────────┴───────────────┴────────────────────────────────────────┘
73
75 These functions are not in POSIX.1. Several operating systems have
76 them, for example, *BSD, SunOS, Digital UNIX, AIX (which also has a
77 getfstype()). HP-UX has functions of the same names, that however use
78 a struct checklist instead of a struct fstab, and calls these functions
79 obsolete, superseded by getmntent(3).
80
82 These functions are not thread-safe.
83 Since Linux allows mounting a block special device in several places,
85 and since several devices can have the same mount point, where the last
86 device with a given mount point is the interesting one, while getfs‐
87 file() and getfsspec() only return the first occurrence, these two
88 functions are not suitable for use under Linux.
89
91 getmntent(3), fstab(5)
92
94 This page is part of release 5.12 of the Linux man-pages project. A
95 description of the project, information about reporting bugs, and the
96 latest version of this page, can be found at
97 https://www.kernel.org/doc/man-pages/.
98GNU 2021-03-22 GETFSENT(3)