/* Part of SWI-Prolog Author: Jan Wielemaker E-mail: J.Wielemaker@vu.nl WWW: http://www.swi-prolog.org Copyright (c) 2006-2015, 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(www_browser, [ www_open_url/1, % +UrlOrSpec expand_url_path/2 % +Spec, -URL ]). :- use_module(library(lists)). :- if(exists_source(library(process))). :- use_module(library(process)). :- endif. :- multifile known_browser/2. /** Open a URL in the users browser This library deals with the highly platform specific task of opening a web page. In addition, is provides a mechanism similar to absolute_file_name/3 that expands compound terms to concrete URLs. For example, the SWI-Prolog home page can be opened using: == ?- www_open_url(swipl(.)). == */ %! www_open_url(+Url) % % Open URL in running version of the users' browser or start a new % browser. This predicate tries the following steps: % % 1. If a prolog flag (see set_prolog_flag/2) =browser= is set % and this is the name of a known executable, use this. The % flag may be set to `Command-Mode`, where mode is one of `fg` % or `bg`, requesting Command to run in foreground or background % mode. Default is `bg`. % % 2. On Windows, use win_shell(open, URL) % % 3. Find a generic `open' comment. Candidates are =xdg-open=, % =open= or =|gnome-open|=. % % 4. If a environment variable =BROWSER= is set % and this is the name of a known executable, use this. % % 5. Try to find a known browser. % % @tbd Figure out the right tool in step 3 as it is not % uncommon that multiple are installed. www_open_url(Spec) :- % user configured expand_url_path(Spec, URL), open_url(URL). open_url(URL) :- current_prolog_flag(browser, Browser), expand_browser_flag(Browser, Command, Mode), has_command(Command), !, run_command(Command, [URL], Mode). :- if(current_predicate(win_shell/2)). open_url(URL) :- % Windows shell win_shell(open, URL). :- endif. open_url(URL) :- % Unix `open document' open_command(Open), has_command(Open), !, run_command(Open, [URL], fg). open_url(URL) :- % user configured getenv('BROWSER', Browser), has_command(Browser), !, run_browser(Browser, URL). open_url(URL) :- % something we know known_browser(Browser, _), has_command(Browser), !, run_browser(Browser, URL). expand_browser_flag(Command-Mode, Command, Mode) :- !. expand_browser_flag(Command, Command, bg) :- atomic(Command). open_command(open) :- % Apples open command current_prolog_flag(apple, true). open_command('xdg-open'). % Free desktop open_command('gnome-open'). % Gnome (deprecated in favour of xdg-open open_command(open). % Who knows %! run_browser(+Browser, +URL) is det. % % Open a page using a browser. run_browser(Browser, URL) :- run_command(Browser, [URL], bg). %! run_command(+Command, +Args, +Background) % % Run OS command Command using Args, silencing the error output % because many browsers are rather verbose. :- if(current_predicate(process_create/3)). run_command(Command, Args, fg) :- !, process_create(path(Command), Args, [stderr(null)]). :- endif. :- if(current_prolog_flag(unix, true)). run_command(Command, [Arg], fg) :- format(string(Cmd), "\"~w\" \"~w\" &> /dev/null", [Command, Arg]), shell(Cmd). run_command(Command, [Arg], bg) :- format(string(Cmd), "\"~w\" \"~w\" &> /dev/null &", [Command, Arg]), shell(Cmd). :- else. run_command(Command, [Arg], fg) :- format(string(Cmd), "\"~w\" \"~w\"", [Command, Arg]), shell(Cmd). run_command(Command, [Arg], bg) :- format(string(Cmd), "\"~w\" \"~w\" &", [Command, Arg]), shell(Cmd). :- endif. %! known_browser(+FileBaseName, -Compatible) % % True if browser FileBaseName has a remote protocol compatible to % Compatible. known_browser(firefox, netscape). known_browser(mozilla, netscape). known_browser(netscape, netscape). known_browser(konqueror, -). known_browser(opera, -). %! has_command(+Command) % % Succeeds if Command is in $PATH. Works for Unix systems. For % Windows we have to test for executable extensions. :- dynamic command_cache/2. :- volatile command_cache/2. has_command(Command) :- command_cache(Command, Path), !, Path \== (-). has_command(Command) :- ( getenv('PATH', Path), ( current_prolog_flag(windows, true) -> Sep = (;) ; Sep = (:) ), atomic_list_concat(Parts, Sep, Path), member(Part, Parts), prolog_to_os_filename(PlPart, Part), atomic_list_concat([PlPart, Command], /, Exe), access_file(Exe, execute) -> assert(command_cache(Command, Exe)) ; assert(command_cache(Command, -)), fail ). /******************************* * NET PATHS * *******************************/ %! url_path(+Alias, -Expansion) is nondet. % % Define URL path aliases. This multifile predicate is defined in % module =user=. Expansion is either a URL, or a term Alias(Sub). :- multifile user:url_path/2. user:url_path(swipl, 'http://www.swi-prolog.org'). user:url_path(swipl_book, 'http://books.google.nl/books/about/\c SWI_Prolog_Reference_Manual_6_2_2.html?\c id=q6R3Q3B-VC4C&redir_esc=y'). user:url_path(swipl_faq, swipl('FAQ')). user:url_path(swipl_man, swipl('pldoc/doc_for?object=manual')). user:url_path(swipl_mail, swipl('Mailinglist.html')). user:url_path(swipl_download, swipl('Download.html')). user:url_path(swipl_pack, swipl('pack/list')). user:url_path(swipl_bugs, swipl('bugzilla/')). user:url_path(swipl_quick, swipl('man/quickstart.html')). %! expand_url_path(+Spec, -URL) % % Expand URL specifications similar to absolute_file_name/3. The % predicate url_path/2 plays the role of file_search_path/2. % % @error existence_error(url_path, Spec) if the location is not % defined. expand_url_path(URL, URL) :- atomic(URL), !. % Allow atom and string expand_url_path(Spec, URL) :- Spec =.. [Path, Local], ( user:url_path(Path, Spec2) -> expand_url_path(Spec2, URL0), ( Local == '.' -> URL = URL0 ; sub_atom(Local, 0, _, _, #) -> atom_concat(URL0, Local, URL) ; atomic_list_concat([URL0, Local], /, URL) ) ; throw(error(existence_error(url_path, Path), expand_url_path/2)) ).