[Unix] (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
grep1,
sed1,
and
awk1.
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.