bionic (3) getfsent.3.gz

NAME

       getfsent, getfsspec, getfsfile, setfsent, endfsent - handle fstab entries

SYNOPSIS

       #include <fstab.h>

       void endfsent(void);

       struct fstab *getfsent(void);

       struct fstab *getfsfile(const char *mount_point);

       struct fstab *getfsspec(const char *special_file);

       int setfsent(void);

DESCRIPTION

       These functions read from the file /etc/fstab.  The struct fstab is defined by:

           struct fstab {
               char       *fs_spec;       /* block device name */
               char       *fs_file;       /* mount point */
               char       *fs_vfstype;    /* file-system type */
               char       *fs_mntops;     /* mount options */
               const char *fs_type;       /* rw/rq/ro/sw/xx option */
               int         fs_freq;       /* dump frequency, in days */
               int         fs_passno;     /* pass number on parallel dump */
           };

       Here  the  field fs_type contains (on a *BSD system) one of the five strings "rw", "rq", "ro", "sw", "xx"
       (read-write, read-write with quota, read-only, swap, ignore).

       The function setfsent() opens the file when required and positions it at the first line.

       The function getfsent() parses the next line from the file.  (After opening it when required.)

       The function endfsent() closes the file when required.

       The function getfsspec() searches the file from the start and returns the first entry found for which the
       fs_spec field matches the special_file argument.

       The function getfsfile() searches the file from the start and returns the first entry found for which the
       fs_file field matches the mount_point argument.

RETURN VALUE

       Upon success, the functions getfsent(), getfsfile(), and getfsspec() return a pointer to a struct  fstab,
       while  setfsent()  returns  1.   Upon  failure  or  end-of-file,  these  functions  return  NULL  and  0,
       respectively.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       ┌─────────────┬───────────────┬─────────────────────────────┐
       │Interface    │ Attribute     │ Value                       │
       ├─────────────┼───────────────┼─────────────────────────────┤
       │endfsent(),  │ Thread safety │ MT-Unsafe race:fsent        │
       │setfsent()   │               │                             │
       ├─────────────┼───────────────┼─────────────────────────────┤
       │getfsent(),  │ Thread safety │ MT-Unsafe race:fsent locale │
       │getfsspec(), │               │                             │
       │getfsfile()  │               │                             │
       └─────────────┴───────────────┴─────────────────────────────┘

CONFORMING TO

       These functions are not in POSIX.1.  Several operating systems  have  them,  for  example,  *BSD,  SunOS,
       Digital  UNIX,  AIX  (which also has a getfstype()).  HP-UX has functions of the same names, that however
       use a struct checklist instead of a struct fstab, and  calls  these  functions  obsolete,  superseded  by
       getmntent(3).

NOTES

       These functions are not thread-safe.

       Since  Linux allows mounting a block special device in several places, and since several devices can have
       the same mount point, where the last device with a given  mount  point  is  the  interesting  one,  while
       getfsfile()  and  getfsspec()  only return the first occurrence, these two functions are not suitable for
       use under Linux.

SEE ALSO

       getmntent(3), fstab(5)

COLOPHON

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