System Administration Guide: Network Services

Autofs and Metacharacters

Autofs recognizes some characters as having a special meaning. Some characters are used for substitutions, and some characters are used to protect other characters from the autofs map parser.

Ampersand (&)

If you have a map with many subdirectories specified, as in the following, consider using string substitutions.

john        willow:/home/john
mary        willow:/home/mary
joe         willow:/home/joe
able        pine:/export/able
baker       peach:/export/baker

You can use the ampersand character (&) to substitute the key wherever the key appears. If you use the ampersand, the previous map changes to the following:

john        willow:/home/&
mary        willow:/home/&
joe         willow:/home/&
able        pine:/export/&
baker       peach:/export/&

You could also use key substitutions in a direct map, in situations such as the following:

/usr/man						willow,cedar,poplar:/usr/man

You can also simplify the entry further as follows:

/usr/man						willow,cedar,poplar:&

Notice that the ampersand substitution uses the whole key string. Therefore, if the key in a direct map starts with a / (as it should), the slash is included in the substitution. Consequently, for example, you could not do the following:

/progs				&1,&2,&3:/export/src/progs 

The reason is that autofs would interpret the example as the following:

/progs 				/progs1,/progs2,/progs3:/export/src/progs

Asterisk (*)

You can use the universal substitute character, the asterisk (*), to match any key. You could mount the /export file system from all hosts through this map entry.

*						&:/export

Each ampersand is substituted by the value of any given key. Autofs interprets the asterisk as an end-of-file character.