NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ATTRIBUTES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

GETFSENT(3)               Linux Programmer's Manual              GETFSENT(3)

NAME         top

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

SYNOPSIS         top

       #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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       getmntent(3), fstab(5)

COLOPHON         top

       This page is part of release 4.08 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.

GNU                              2015-03-02                      GETFSENT(3)