[Unix] Term used for shell code, so called because of the prevalence of pipelines that feed the output of one program to the input of another. Under Unix, user utilities can often be implemented or at least prototyped by a suitable collection of pipelines and temp-file grinding encapsulated in a shell script; this is much less effort than writing C every time, and the capability is considered one of Unix's major winning features. A few other OSs such as IBM's VM/CMS support similar facilities. Esp.: used in the construction hairy plumbing (see hairy). “You can kluge together a basic spell-checker out of sort(1), comm(1), and tr(1) with a little plumbing.” See also tee.