Grep Software

GREP (global regular expression print) is essentially a tool for finding snippets within text files. It has been around as a command line tool for a very long time in unix systems.

There are a number of GUI GREP tools out there as well if you don't like the command line, though I suggest getting familar with it because it is almost always more efficient, and on servers, you may not have a nice GUI in front of you!

AstroGrep

PowerGREP

dnGrep

SearchMonkey

Also don't forget a lot of good text editors include Grep in the Find in Files functionality.