highlight-regexp

highlight-regexp is an alias for `hi-lock-face-buffer' in `hi-lock.el'.

It is bound to M-s h r.

(highlight-regexp REGEXP &optional FACE)

Set face of each match of REGEXP to FACE.
Interactively, prompt for REGEXP using `read-regexp', then FACE.
Use the global history list for FACE.

Use Font lock mode, if enabled, to highlight REGEXP. Otherwise,
use overlays for highlighting. If overlays are used, the
highlighting will not update as you type.