regexp: /reg'eksp/ [UNIX] n. (alt. `regex' or `reg-ex') 1.

:regexp: /reg'eksp/ [UNIX] n. (alt. `regex' or `reg-ex')
1. Common written and spoken abbreviation for `regular
expression', one of the wildcard patterns used, e.g., by UNIX
utilities such as `grep(1)', `sed(1)', and `awk(1)'.
These use conventions similar to but more elaborate than those
described under {glob}. For purposes of this lexicon, it is
sufficient to note that regexps also allow complemented character
sets using `^'; thus, one can specify `any non-alphabetic
character' with `[^A-Za-z]'. 2. Name of a well-known PD
regexp-handling package in portable C, written by revered USENETter
Henry Spencer <henry@zoo.toronto.edu>.
-- The AI Hackers Dictionary