NAME

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

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #include <fstab.h>

       int setfsent(void);
       struct fstab *getfsent(void);
       void endfsent(void);

       struct fstab *getfsfile(const char *mount_point);
       struct fstab *getfsspec(const char *special_file);

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;    /* filesystem 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(), setfsent()   │ Thread safety │ MT-Unsafe race:fsent                                       │
       ├──────────────────────────┼───────────────┼────────────────────────────────────────────────────────────┤
       │ getfsent(), getfsspec(), │ Thread safety │ MT-Unsafe race:fsent locale                                │
       │ getfsfile()              │               │                                                            │
       └──────────────────────────┴───────────────┴────────────────────────────────────────────────────────────┘

VERSIONS

       Several operating systems have these functions, 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).

STANDARDS

       None.

HISTORY

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

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)

Linux man-pages 6.7                                2023-10-31                                        getfsent(3)