This is flex, the fast lexical analyzer generator.

flex is a tool for generating scanners: programs which recognize lexical patterns in text.

The flex codebase is kept in Git on GitHub. Source releases of flex with some intermediate files already built can be found on the github releases page.

Use GitHub's issues and pull request features to file bugs and submit patches.

There are several mailing lists available as well:

• flex-announce@lists.sourceforge.net - where posts will be made announcing new releases of flex.
• flex-help@lists.sourceforge.net - where you can post questions about using flex
• flex-devel@lists.sourceforge.net - where you can discuss development of flex itself

Find information on subscribing to the mailing lists or search in the archive at: https://sourceforge.net/p/flex/mailman/ Note: Posting is only allowed from addresses that are subscribed to the lists.

The flex distribution contains the following files which may be of interest:

• README.md - This file.
• NEWS - current version number and list of user-visible changes.
• INSTALL.md - basic installation information.
• ABOUT-NLS - description of internationalization support in flex.
• COPYING - flex's copyright and license.
• doc/ - user documentation.
• examples/ - containing examples of some possible flex scanners and a few other things. See the file examples/README for more details.
• tests/ - regression tests. See tests/README for details.
• po/ - internationalization support files.

This file is part of flex.

This code is derived from software contributed to Berkeley by Vern Paxson.

The United States Government has rights in this work pursuant to contract no. DE-AC03-76SF00098 between the United States Department of Energy and the University of California.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

Neither the name of the University nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.