Korn Shell Programming by Example

hash

Official Description

Remembers or reports utility locations.

Syntax

hash [utility]

Options

-r forgets remembered locations.

Oddities

The hash command is an alias for alias -t. It sets up tracked aliases. (Not heavily used because processor speeds and caching strategies eliminate the penalty of multiple PATH lookups.)

Example

$ hash                       # Nothing remembered yet
$
$ hash ls                    # Remember the location of ls
$
$ hash                       # In the list now
ls=/bin/ls
$
$ hash cat                   # Location of cat will be remembered also
$
$ hash                       # Both in the hash list
cat=/bin/cat
ls=/bin/ls
$
$ hash –r                    # Refresh the list
$
$ hash                       # Names are known, locations aren't
cat
ls
$