AUTOFS(5)							File Formats Manual							 AUTOFS(5)

NAME

       autofs - Format of the automounter maps

DESCRIPTION

       The  automounter  maps  are  files or NIS maps referred to by the master map of the automounter (see auto.master(5)).  The automounter maps
       describe how file systems below the mountpoint of the map (given in the auto.master file) are to be mounted.  This describes  the  sun  map
       format; if another map format is specified (e.g. hesiod), this documentation does not apply.

       Maps  can be changed on the fly and the automouter will recognize those changes on the next operation it performs on that map.  This is not
       true for the auto.master map!

FORMAT

       This is a description of the text file format.  Other methods of specifying these files may exist.  All empty lines or lines beginning with
       # are ignored. The basic format of one line in such maps is:

       key [-options] location

   key
       is the part of the pathname between the mountpoint and the path into the filesystem mounted.  Usually you can think about the key as a sub-
       directory name below the mountpoint.

   options
       Options are optional.  Options can also be given in the auto.master file in which case both values are cumulative  (this  is  a	difference
       from  SunOS).   The options are a list of comma separated options as customary for the mount(8) command. There is a special option -fstype=
       used to specify a filesystem type if the filesystem is not of the default NFS type.  This option is processed by the automounter and not by
       the mount command.

   location
       The  location  specifies  from where the file system is to be mounted.  In the most cases this will be an NFS volume and the usual notation
       host:pathname is used to indicate the remote filesystem and path to be mounted.	If the filesystem to be mounted begins with a /  (such	as
       local /dev entries or smbfs shares) a : needs to be prefixed (e.g.  :/dev/sda1).

EXAMPLE

	 kernel    -ro,soft,intr       ftp.kernel.org:/pub/linux
	 boot	   -fstype=ext2        :/dev/hda1
	 windoze   -fstype=smbfs       ://windoze/c
	 removable -fstype=ext2        :/dev/hdd
	 cd	   -fstype=iso9660,ro  :/dev/hdc
	 floppy    -fstype=auto        :/dev/fd0

       In the first line we have a NFS remote mount of the kernel directory on ftp.kernel.org.	This is mounted read-only.  The second line mounts
       an ext2 volume on a local ide drive.  The third makes a share exported from a Windows machine available for automounting.  The rest  should
       be fairly self-explanatory.

FEATURES

   Map Key Substitution
       An  &  character  in the location is expanded to the value of the key field that matched the line (which probably only makes sense together
       with a wildcard key).

   Wildcard Key
       A * in the key field matches all keys.  An example for the usefulness is the following entry:

	 *	   &:/home/&

       This will enable you to access all the home directory of local hosts using the path /mountpoint/hostname/local-path.

   Variable Substitution
       The following special variables will be substituted in the key and location fields of an automounter map if prefixed with  $  as  customary
       from shell scripts (Curly braces can be used to separate the fieldname):

	 ARCH		Architecture (uname -m)
	 CPU		Processor Type
	 HOST		Hostname (uname -n)
	 OSNAME 	Operating System (uname -s)
	 OSREL		Release of OS (uname -r)
	 OSVERS 	Version of OS (uname -v)

       Additional entries can be defined with the -Dvariable=Value option to automount(8).

   Executable Maps
       A  map can be marked as executable.  The init script that parses the auto.master map will pass this as a program map to the automounter.  A
       program map will be called as a script with the key as an argument.  The script needs to return one line of a map or no output  at  all	if
       the key cannot be matched.

       To do this the automount(8) daemon has to be started with the program type insted of the file type.  This is implemented in the initializa-
       tion script.

       A executable map can return an errorcode to indicate the failure in addition to no output at all.  All output sent to stderr is logged into
       the system logs.

UNSUPPORTED

       The  automounter does not support direct maps or mount trees (more than one filesystem to be mounted under a specific automount point), and
       handles SunOS-style replicated filesystems only to the extent that mount(8) does.

SEE ALSO

       automount(8), auto.master(5), autofs(8), mount(8).

AUTHOR

       This manual page was written by Christoph Lameter  <chris@waterf.org>,  for  the  Debian  GNU/Linux  system.   Edited  by  H.  Peter  Anvin
       <hpa@transmeta.com>.

								    6 Apr 1998								 AUTOFS(5)