from Wiktionary, Creative Commons Attribution/Share-Alike License
- proper n. A program which selects lines in a file which match a given pattern.
- v. To use a program such as grep to search in a file.
- v. By extension, to search anything (perhaps a paper document by eye).
From an idiomatic command sequence in the qed and ed text editors: ‘g/re/p’, meaning: globally search for a regular expression and print. (Wiktionary)