In vim, the command :g/re/p (where g means "global", re is clearly "regex" and p means "print") will find all lines matching the regex and print them in a list. This was apparently true of vim's predecessors as well, but it's still a valid (and useful) command in vim today. See also Wikipedia.
Comment on Re^2: question for perl book & magazine authors
The g/re/p command actually goes back to ed, which was the original Unix editor, back around 1972, and is still provided with all Unix systems. After ed came vi, the visual editor, with command syntax similar to ed's, and then vim, which is an improved version of vi.
Early versions of Unix also had a gres command (perform a substitution on all matching lines) but it was obsoleted by sed and abandoned.