shFlags is a port of the Google gflags library for Unix shell. The code is
written in a way to be as portable as possible to work across a wide array of
Unix variants.

shFlags is simply a library that you include into an existing shell script that
gives you some additional functions that can be called. The power behind those
functions though is somewhat amazing though, and you will hopefully be amazed
with the simplicity with which you can handle command-line arguments in shell.

WWW: https://github.com/kward/shflags