Code Search is a tool for indexing and then performing
regular expression searches over large bodies of source code.
It is a set of command-line programs written in Go.
Binary downloads are available for those who do not have Go installed.
See http://code.google.com/p/codesearch/

For background and an overview of the commands,
see http://swtch.com/~rsc/regexp/regexp4.html.

Russ Cox 
January 2012