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(8)). 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!
AUTO.MASTER
  Each line that is no comment in auto.master(8) will deliver the arguments for a single automounter process. The format is therefore different from the other maps that provide input to these processes.
  If you need to disable maps temporarily, please add a comment sign in front of the line concerned and restart the automounter.
FILE TYPE MAPS
  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 subdirectory 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 auto­ mounter 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 -Dvari­ able=Value option to automount(8).
PROGRAM TYPE 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 that only contains options and location 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 imple­ mented in the initialization 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.
EXAMPLE
  If the program map should allow the same mounts as the file map it should answer if called with the argument "kernel" 
        -ro,soft,intr       ftp.kernel.org:/pub/linux
and if called with the argument "boot" it should state 
        -fstype=ext2        :/dev/hda1
to allow the same behaviour,
UNSUPPORTED
  The automounter does not support direct maps or mount trees (more than one filesystem to be mounted under a spe­ cific 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 , for the Debian GNU/Linux system. Edited by H. Peter Anvin and Andreas Neuper (Andreas(at)Neuper(dot)de)