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   autofs    ( 5 )

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AMD FORMAT

This is a description of the text file format. Other methods of specifying mount map entries may be required for different map sources. All empty lines or lines beginning with # are ignored. The basic format of one line in such maps is:

key location-list

key A key is a path (or a single path component alone) that may end in the wildcard key, "*", or the wildcard key alone and must not begin with the "/" character.

location-list Following the key is a mount location-list.

A location-list list has the following syntax:

location[ location[ ... ]] [|| location[ location[ ... ]]

A mount location-list can use the cut operator, ||, to specify locations that should be tried if none of the locations to the left of it where selected for a mount attempt.

A mount location consists of an optional colon separated list of selectors, followed by a colon separated list of option:=value pairs.

The selectors that may be used return a value or boolean result. Those that return a value may be to used with the comparison operators == and != and those that return a boolean result may be negated with the !.

For a location to be selected for a mount attempt all of its selectors must evaluate to true. If a location is selected for a mount attempt and succeeds the lookup is completed and returns success. If the mount attempt fails the procedure continues with the next location until they have all been tried.

In addition, some selectors take no arguments, some one argument and others optionally take two arguments.

The selectors that take no arguments are:

arch The machine architecture which, if not set in the configuration, is obtained using uname(2).

karch The machine kernel architecture which, if not set in the configuration, is obtained using uname(2).

os The operating system name, if not set in the configuration, is obtained using uname(2).

osver The operating system version, if not set in the configuration, is obtained using uname(2).

full_os The full operating system name, if not set in the configuration this selector has no value.

vendor The operating system vendor name, if not set in the configuration this selector has the value "unknown".

byte The endianness of the hardware.

cluster The name of the local cluster. It has a value only if it is set in the configuration.

autodir The base path under which external mounts are done if they are needed. Most mounts are done in place but some can't be and this is the base path under which those mounts will be done.

domain The local domain name. It is set to the value of the configuration option sub_domain. If sub_domain is not given in the configuration it is set to the domain part of the local host name, as given by gethostname(2).

host The local host name, without the domain part, as given by gethostname(2).

hostd The full host name. If sub_domain is given in the configuration this is set to the contatenation of host and sub_domain deperated by a .. If sub_domain is not set in the configuration the value of domain is used instead of sub_domain.

uid The numeric value of the uid of the user that first requested the mount. Note this is usual the same as that used by amd but can be different within autofs.

gid The numeric value of the gid of the user that first requested the mount. Note this is usual the same as that used by amd but can be different within autofs.

key The string value of the key being looked up.

map The string value of the map name used to lookup keys.

path The string value of the full path to the mount being requested.

dollar Evaluates to the string "$".

The selectors that take one argument are:

in_network(network) , network(network) , netnumber(network) , wire(network) These selectors are all the same. in_network() is the preferred usage. The network argument is an address (which may include a subnet mask) or network name. The function compares network against each interface and returns true if network belongs to the network the interface is connected to.

xhost(hostname) The xhost() selector compares hostname to the ${host} and if it doesn't match it attempts to lookup the cannonical name of hostname and compares it to {host} as well.

exists(filename) Returns true if filename exits as determined by lstat(2).

true() Evaluates to true, the argument is ignored and may be empty.

false() Evaluates to false, the argument is ignored and may be empty.

The selectors that take up to two arguments are:

netgrp(netgroup[,hostname]) The netgrp() selector returns true if hostname is a member of the netgroup netgroup. If hostname is not given ${host} is used for the comparison.

netgrpd(netgroup[,hostname]) The netgrpd()i selector behaves the same as netgrp() except that if hostname is not given ${hostd}, the fully qualified hostname, is used instead of ${host}.

The options that may be used are:

type This is the mount filesystem type. It can have a value of auto, link, linkx, host, lofs, ext2-4, xfs, nfs, nfsl or cdfs. Other types that are not yet implemented or are not available in autofs are nfsx, lustre, jfs, program, cachefs and direct.

maptype The maptype option specifies the type of the map source and can have a value of file, nis, nisplus, exec, ldap or hesiod. Map sources either not yet implemented or not available in autofs are sss, ndbm, passwd and union.

fs The option fs is used to specify the local filesystem. The meaning of this option (and whether or not it is used) is dependent on the mount filesystem type.

rhost The remote host name for network mount requests.

rfs The remote host filesystem path for network mount requests.

dev Must resolve to the device file for local device mount requests.

sublink The sublink option is used to specify a subdirectory within the mount location to which this entry will point.

pref The pref option is used to specify a prefix that is prepended to the lookup key before looking up the map entry key.

opts The opts option is used to specify mount options to be used for the mount. If a "-" is given it is ignored. Options that may be used are dependend on the mount filesystem.

addopts The addopts option is used to specify additional mount options used in addition to the default mount options for the mount location.

remopts The addopts option is used to specify mount options used instead the options given in opts when the mount location is on a remote retwork.

A number of options aren't available or aren't yet implemented within autofs, these are:

cache The cache option isn't used by autofs. The map entry cache is continually updated and stale entries cleaned on re-load when map changes are detected so these configuration entries are not used. The regex map key matching is not implemented and may not be due to the potential overhead of the full map scans needed on every key lookup.

cachedir The cachefs filesystem is not available on Linux, a different implementation is used for caching network mounted file systems.

mount , unmount , umount These options are used by the amd program mount type which is not yet implemented.

delay This option is not used by the autofs implementation and is ignored.