GREP (Wordhole)

From XPUB & Lens-Based wiki

A command-line utility for searching in plain-text data sets for patterns (eg. for regular expressions). It can be a powerful tool (alone or even better along other commands, for finding and handling elements in a text or list.

In context

The function of this command-line is so important that it has entered the Oxford English Dictionary (2003) both as a verb and noun. (Famous phrase: "You can't grep dead trees", referring to physical data)