setfsent(3)

1getfsent(3)                Library Functions Manual                getfsent(3)
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NAME

6       getfsent,  getfsspec,  getfsfile, setfsent, endfsent - handle fstab en‐
7       tries
8

LIBRARY

10       Standard C library (libc, -lc)
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SYNOPSIS

13       #include <fstab.h>
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15       int setfsent(void);
16       struct fstab *getfsent(void);
17       void endfsent(void);
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19       struct fstab *getfsfile(const char *mount_point);
20       struct fstab *getfsspec(const char *special_file);
21

DESCRIPTION

23       These functions read from the file /etc/fstab.  The struct fstab is de‐
24       fined by:
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26           struct fstab {
27               char       *fs_spec;       /* block device name */
28               char       *fs_file;       /* mount point */
29               char       *fs_vfstype;    /* filesystem type */
30               char       *fs_mntops;     /* mount options */
31               const char *fs_type;       /* rw/rq/ro/sw/xx option */
32               int         fs_freq;       /* dump frequency, in days */
33               int         fs_passno;     /* pass number on parallel dump */
34           };
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36       Here  the  field  fs_type  contains  (on a *BSD system) one of the five
37       strings "rw", "rq",  "ro",  "sw",  "xx"  (read-write,  read-write  with
38       quota, read-only, swap, ignore).
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40       The  function  setfsent() opens the file when required and positions it
41       at the first line.
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43       The function getfsent() parses the next line  from  the  file.   (After
44       opening it when required.)
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46       The function endfsent() closes the file when required.
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48       The  function  getfsspec() searches the file from the start and returns
49       the first entry found for which the  fs_spec  field  matches  the  spe‐
50       cial_file argument.
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52       The  function  getfsfile() searches the file from the start and returns
53       the  first  entry  found  for  which  the  fs_file  field  matches  the
54       mount_point argument.
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RETURN VALUE

57       Upon  success,  the  functions getfsent(), getfsfile(), and getfsspec()
58       return a pointer to a struct fstab, while setfsent() returns  1.   Upon
59       failure  or  end-of-file,  these  functions  return NULL and 0, respec‐
60       tively.
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ATTRIBUTES

63       For an  explanation  of  the  terms  used  in  this  section,  see  at‐
64       tributes(7).
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66       ┌─────────────┬───────────────┬────────────────────────────────────────┐
67       │Interface    │ Attribute     │ Value                                  │
68       ├─────────────┼───────────────┼────────────────────────────────────────┤
69       │endfsent(),  │ Thread safety │ MT-Unsafe race:fsent                   │
70       │setfsent()   │               │                                        │
71       ├─────────────┼───────────────┼────────────────────────────────────────┤
72       │getfsent(),  │ Thread safety │ MT-Unsafe race:fsent locale            │
73       │getfsspec(), │               │                                        │
74       │getfsfile()  │               │                                        │
75       └─────────────┴───────────────┴────────────────────────────────────────┘
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VERSIONS

78       Several operating systems have  these  functions,  for  example,  *BSD,
79       SunOS,  Digital  UNIX,  AIX  (which also has a getfstype()).  HP-UX has
80       functions of the same names, that however use a  struct  checklist  in‐
81       stead of a struct fstab, and calls these functions obsolete, superseded
82       by getmntent(3).
83

STANDARDS

85       None.
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HISTORY

88       The getfsent() function appeared in 4.0BSD; the  other  four  functions
89       appeared in 4.3BSD.
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NOTES

92       These functions are not thread-safe.
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94       Since  Linux  allows mounting a block special device in several places,
95       and since several devices can have the same mount point, where the last
96       device  with  a  given mount point is the interesting one, while getfs‐
97       file() and getfsspec() only return  the  first  occurrence,  these  two
98       functions are not suitable for use under Linux.
99