small self-containing non-backtracking regular expression engine. supports greedy and non-greedy closures, capturing and non-capturing groups, comments, metacharactes, posix classes, case-insensitive matching in utf-8 mode, matching with non-asciiz strings. consists of three files: re9.h, re9.c (engine) and optional re9_unicode_mapping.c for utf-8 case insensitivity. will add ~20 kb to your binary (~35 kb with utf-8 case insensitivity).