Erlang command-line option handling

options.erl

#!/usr/bin/escript

-module(options).

% main/1 calls main/3 with default values
main(Args) -> main(false, "", Args).

main(_,    _,     ["-h"        | _    ] ) -> io:format("Help text...~n");  % help
main(_,    Value, ["-f"        | Args ] ) -> main(true, Value, Args);      % set flag
main(Flag, _,     ["-v", Value | Args ] ) -> main(Flag, Value, Args);      % set value
main(Flag, Value, Args)                   -> do_stuff(Flag, Value, Args).  % go!

do_stuff(Flag, Value, Args) ->
    %% Do stuff
    ok.