/reg'eksp/ n. [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 `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 <>.