Enhanced AutoFS Administrator's Guide

Configuring and Administering AutoFS
Executable Maps
Chapter 3 43
Executable Maps
An executable map has its entries generated dynamically by a program
or a script. AutoFS determines whether a map is executable by checking
whether the execute bit is set in its permissions string. If a map is not
executable, make sure its execute bit is not set.
When the AutoFS daemon locates a map and detects that its execute bit
is set, then instead of opening the file and searching for an entry, the
AutoFS daemon executes the file as a program and passes the key to be
located within the map as an argument. The executable AutoFS map
returns a map entry on the standard output. If they cannot supply a map
entry for the key, they should return nothing. You can list executable
AutoFS maps in the master map or include them in local AutoFS map
files.
For example, the following executable map, implemented as a shell
script, emulates the AutoFS built-in -hosts map for /net. It obtains a
list of exported file systems from an NFS server (its name given as the
key argument), formats the path names into a multiple-mount map
entry, and sorts the list to order the mounts correctly into a top-down
hierarchy:
# ! /bin/sh
Server=$1
showmount -e $1 | awk ‘{print $1 “\t’$Server’: $1 “\\”} | sort