NAME

fstab − static information about the filesystems

SYNOPSIS

#include <fstab.h>

DESCRIPTION

The file /etc/fstab contains descriptive information about the various file systems.  /etc/fstab is only read by programs, and not written; it is the duty of the system administrator to properly create and maintain this file. 

These programs use /etc/fstab: dump, mount, umount, swapon, fsck and df.  The order of records in /etc/fstab is important, for both fsck, mount, and umount sequentially iterate through /etc/fstab doing their thing. 

The special file name is the block special file name, and not the character special file name.  If a program needs the character special file name, the program must create it by appending a “r” after the last “/” in the special file name. 

If fs_type is “rw” or “ro” then the file system whose name is given in the fs_file field is normally mounted read-write or read-only on the specified special file.  The fs_freq field is used for these file systems by the dump(8) command to determine which file systems need to be dumped. The fs_passno field is used by the fsck(8) program to determine the order in which file system checks are done at reboot time. The root file system should be specified with a fs_passno of 1, and other file systems should have larger numbers.  File systems within a drive should have distinct numbers, but file systems on different drives can be checked on the same pass to utilize parallelism available in the hardware. 

If fs_type is “sw” then the special file is made avaiable as a piece of swap space by the swapon(8) command at the end of the system reboot procedure. The fields other than fs_spec and fs_type are not used in this case. 

Fs_type may be specified as “xx” to cause an entry to be ignored.  This is useful to show disk partitions which are currently not used but will be used later. 

#defineFSTAB"/etc/fstab"
#defineFSNMLG16
 #defineFSTABFMT"%16s:%16s:%2s:%d:%d\n"
#defineFSTABARG(p)(p)−>fs_spec, (p)−>fs_file, \
(p)−>fs_type, &(p)−>fs_freq, &(p)−>fs_passno
#defineFSTABNARGS5
 #defineFSTAB_RW"rw"/\(** read write device \(**/
#defineFSTAB_RO"ro"/\(** read only device \(**/
#defineFSTAB_SW"sw"/\(** swap device \(**/
#defineFSTAB_XX"xx"/\(** ignore totally \(**/
 struct fstab {
charfs_spec[FSNMLG];/\(** block special device name \(**/
charfs_file[FSNMLG];/\(** file system path prefix \(**/
charfs_type[3];/\(** rw,ro,sw or xx \(**/
intfs_freq;/\(** dump frequency, in days \(**/
intfs_passno;/\(** pass number on parallel dump \(**/
};

The proper way to read records from /etc/fstab is to use the routines getfsent(), getfsspec() or getfsfile(). 

FILES

/etc/fstab

SEE ALSO

getfsent(3)

th Berkeley Distribution