haskell
This library provides an easy way to define command line parsers. Most users
will want to use the "System.Console.CmdArgs.Implicit" module, whose
documentation contains an example.
* "System.Console.CmdArgs.Explicit" provides a way to write command line
parsers for both single mode programs (most programs) and multiple
mode programs (e.g. darcs or cabal). Parsers are defined by constructing
a data structure.
* "System.Console.CmdArgs.Implicit" provides a way to concisely define
command line parsers, up to three times shorter than getopt. These parsers
are translated into the Explicit data type.
* "System.Console.CmdArgs.GetOpt" provides a wrapper allowing compatiblity
with existing getopt parsers, mapping to the Explicit data type.
For a general reference on what command line flags are commonly used,
see <http://www.faqs.org/docs/artu/ch10s05.html>.