The YASP (Yet-Another-Serial-Parser) library is a simple to use command parser 
based on a LUA-like pattern matching lib (from Nick Gammon, see 
http://www.gammon.com.au/forum/?id=11063).  It's first use is for parsing 
serial data on the Arduino, but could be easily extended.  At the moment it 
will work with any interface that uses the Arduino Print class.  It is not 
particularly small or fast, but it is easy to setup and use, which is it's 
main purpose.

See the examples folder for a sketch that illustrates basic usage.

The YASP.h header file includes some references to resources that describe LUA 
pattern matching in more detail.