This library is intended for supporting PrologScript on Unix using 
the
#! magic sequence for scripts using commandline options. 
The entry point main/0 calls 
the user-supplied predicate main/1 passing 
a list of commandline options. Below is `echo' in Prolog (adjust 
/usr/bin/swipl to where SWI-Prolog is installed)
#!/usr/bin/env swipl
:- initialization(main, main).
main(Argv) :-
        echo(Argv).
echo([]) :- nl.
echo([Last]) :- !,
        write(Last), nl.
echo([H|T]) :-
        write(H), write(' '),
        echo(T).
SIGINT (Control-C) that terminates the process 
with status 1.no-, in which case the 
option is mapped to Name(false). Numeric option values are mapped to 
Prolog numbers.