* http://imil.net/docs/BSD-Makefile.txt

  * man pcreapi
  * man pcresample
  * pcredemo.c

  * http://tldp.org/HOWTO/Program-Library-HOWTO/more-examples.html

  * http://www.mentby.com/Group/openbsd-misc/pf-pfctl-and-parsey.html
  * http://ds9a.nl/lex-yacc/#download