dirname

Convert a full pathname to just a path

SYNTAX
     dirname PATHNAME

DESCRIPTION

Prints all but the final slash-delimited component of a
string (presumably a filename).
If PATHNAME is a single component, `dirname' prints `.' 
(meaning the current directory)

Related commands:

hash - Remember the full pathname of a name argument
ls - List information about File(s)
which - Show full path of commands

Equivalent Windows NT commands:

SET Parameters - get a full or partial pathname from a command line variable.