Grep searches one or more input files for lines containing a match to a specified pattern. By default, Grep outputs the matching lines.
Grep can be found on the main GNU ftp server: http://ftp.gnu.org/gnu/grep/ (via HTTP) and ftp://ftp.gnu.org/gnu/grep/ (via FTP). It can also be found on the GNU mirrors; please use a mirror if possible.
For other ways to obtain grep, please read How to get GNU software.
Documentation for Grep is available online, as is documentation for most GNU software. You may also find more information about Grep by running info grep or man grep, or by looking at /usr/share/doc/grep/, /usr/local/doc/grep/, or similar directories on your system. A brief summary is available by running grep --help.
Grep has the following mailing lists:
Security reports that should not be made immediately public can be sent directly to the maintainer. If there is no response to an urgent issue, you can escalate to the general security mailing list for advice.
Development of Grep, and GNU in general, is a volunteer effort, and you can contribute. For information, please read How to help GNU. If you'd like to get involved, it's a good idea to join the bug mailing list (see above).
Grep is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.
The Free Software Foundation is the principal organizational sponsor of the GNU Operating System. Support GNU and the FSF by buying manuals and gear, joining the FSF as an associate member, or making a donation, either directly to the FSF or via Flattr.