/* Part of SWI-Prolog
Author: Jan Wielemaker
E-mail: J.Wielemaker@vu.nl
WWW: http://www.swi-prolog.org
Copyright (c) 2002-2017, University of Amsterdam
VU University Amsterdam
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
:- module(prolog_main,
[ main/0,
argv_options/3 % +Argv, -RestArgv, -Options
]).
/** <module> Provide entry point for scripts
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).
==
@see XPCE users should have a look at library(pce_main), which
starts the GUI and processes events until all windows have gone.
*/
:- module_transparent
main/0.
%! main
%
% Call main/1 using the passed command-line arguments. Before calling
% main/1 this predicate installs a signal handler for =SIGINT=
% (Control-C) that terminates the process with status 1.
main :-
context_module(M),
set_signals,
current_prolog_flag(argv, Av),
call(M:main, Av).
set_signals :-
on_signal(int, _, interrupt).
%! interrupt(+Signal)
%
% We received an interrupt. This handler is installed using
% on_signal/3.
interrupt(_Sig) :-
halt(1).
%! argv_options(+Argv, -RestArgv, -Options) is det.
%
% Generic transformation of long commandline arguments to options.
% Each --Name=Value is mapped to Name(Value). Each plain name is
% mapped to Name(true), unless Name starts with =|no-|=, in which
% case the option is mapped to Name(false). Numeric option values
% are mapped to Prolog numbers.
%
% @see library(optparse) provides a more involved option library,
% providing both short and long options, help and error handling.
% This predicate is more for quick-and-dirty scripts.
argv_options([], [], []).
argv_options([H0|T0], R, [H|T]) :-
sub_atom(H0, 0, _, _, --),
!,
( sub_atom(H0, B, _, A, =)
-> B2 is B-2,
sub_atom(H0, 2, B2, _, Name),
sub_string(H0, _, A, 0, Value0),
convert_option(Name, Value0, Value)
; sub_atom(H0, 2, _, 0, Name0),
( sub_atom(Name0, 0, _, _, 'no-')
-> sub_atom(Name0, 3, _, 0, Name),
Value = false
; Name = Name0,
Value = true
)
),
H =.. [Name,Value],
argv_options(T0, R, T).
argv_options([H|T0], [H|R], T) :-
argv_options(T0, R, T).
convert_option(password, String, String) :- !.
convert_option(_, String, Number) :-
number_string(Number, String),
!.
convert_option(_, String, Atom) :-
atom_string(Atom, String).
:- multifile
prolog:called_by/2.
prolog:called_by(main, [main(_)]).