1/* Part of SWI-Prolog 2 3 Author: Jan Wielemaker 4 E-mail: J.Wielemaker@vu.nl 5 WWW: http://www.swi-prolog.org 6 Copyright (c) 2006-2015, University of Amsterdam 7 VU University Amsterdam 8 All rights reserved. 9 10 Redistribution and use in source and binary forms, with or without 11 modification, are permitted provided that the following conditions 12 are met: 13 14 1. Redistributions of source code must retain the above copyright 15 notice, this list of conditions and the following disclaimer. 16 17 2. Redistributions in binary form must reproduce the above copyright 18 notice, this list of conditions and the following disclaimer in 19 the documentation and/or other materials provided with the 20 distribution. 21 22 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 25 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 26 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 27 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 28 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 29 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 30 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 32 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 POSSIBILITY OF SUCH DAMAGE. 34*/ 35 36:- module(www_browser, 37 [ www_open_url/1, % +UrlOrSpec 38 expand_url_path/2 % +Spec, -URL 39 ]). 40:- use_module(library(lists)). 41:- if(exists_source(library(process))). 42:- use_module(library(process)). 43:- endif. 44 45:- multifile 46 known_browser/2. 47 48/** <module> Open a URL in the users browser 49 50This library deals with the highly platform specific task of opening a 51web page. In addition, is provides a mechanism similar to 52absolute_file_name/3 that expands compound terms to concrete URLs. For 53example, the SWI-Prolog home page can be opened using: 54 55 == 56 ?- www_open_url(swipl(.)). 57 == 58*/ 59 60%! www_open_url(+Url) 61% 62% Open URL in running version of the users' browser or start a new 63% browser. This predicate tries the following steps: 64% 65% 1. If a prolog flag (see set_prolog_flag/2) =browser= is set 66% and this is the name of a known executable, use this. The 67% flag may be set to `Command-Mode`, where mode is one of `fg` 68% or `bg`, requesting Command to run in foreground or background 69% mode. Default is `bg`. 70% 71% 2. On Windows, use win_shell(open, URL) 72% 73% 3. Find a generic `open' comment. Candidates are =xdg-open=, 74% =open= or =|gnome-open|=. 75% 76% 4. If a environment variable =BROWSER= is set 77% and this is the name of a known executable, use this. 78% 79% 5. Try to find a known browser. 80% 81% @tbd Figure out the right tool in step 3 as it is not 82% uncommon that multiple are installed. 83 84www_open_url(Spec) :- % user configured 85 expand_url_path(Spec, URL), 86 open_url(URL). 87 88open_url(URL) :- 89 current_prolog_flag(browser, Browser), 90 expand_browser_flag(Browser, Command, Mode), 91 has_command(Command), 92 !, 93 run_command(Command, [URL], Mode). 94:- if(current_predicate(win_shell/2)). 95open_url(URL) :- % Windows shell 96 win_shell(open, URL). 97:- endif. 98open_url(URL) :- % Unix `open document' 99 open_command(Open), 100 has_command(Open), 101 !, 102 run_command(Open, [URL], fg). 103open_url(URL) :- % user configured 104 getenv('BROWSER', Browser), 105 has_command(Browser), 106 !, 107 run_browser(Browser, URL). 108open_url(URL) :- % something we know 109 known_browser(Browser, _), 110 has_command(Browser), 111 !, 112 run_browser(Browser, URL). 113 114expand_browser_flag(Command-Mode, Command, Mode) :- !. 115expand_browser_flag(Command, Command, bg) :- atomic(Command). 116 117open_command(open) :- % Apples open command 118 current_prolog_flag(apple, true). 119open_command('xdg-open'). % Free desktop 120open_command('gnome-open'). % Gnome (deprecated in favour of xdg-open 121open_command(open). % Who knows 122 123%! run_browser(+Browser, +URL) is det. 124% 125% Open a page using a browser. 126 127run_browser(Browser, URL) :- 128 run_command(Browser, [URL], bg). 129 130%! run_command(+Command, +Args, +Background) 131% 132% Run OS command Command using Args, silencing the error output 133% because many browsers are rather verbose. 134 135:- if(current_predicate(process_create/3)). 136run_command(Command, Args, fg) :- 137 !, 138 process_create(path(Command), Args, [stderr(null)]). 139:- endif. 140:- if(current_prolog_flag(unix, true)). 141run_command(Command, [Arg], fg) :- 142 format(string(Cmd), "\"~w\" \"~w\" &> /dev/null", [Command, Arg]), 143 shell(Cmd). 144run_command(Command, [Arg], bg) :- 145 format(string(Cmd), "\"~w\" \"~w\" &> /dev/null &", [Command, Arg]), 146 shell(Cmd). 147:- else. 148run_command(Command, [Arg], fg) :- 149 format(string(Cmd), "\"~w\" \"~w\"", [Command, Arg]), 150 shell(Cmd). 151run_command(Command, [Arg], bg) :- 152 format(string(Cmd), "\"~w\" \"~w\" &", [Command, Arg]), 153 shell(Cmd). 154:- endif. 155 156%! known_browser(+FileBaseName, -Compatible) 157% 158% True if browser FileBaseName has a remote protocol compatible to 159% Compatible. 160 161known_browser(firefox, netscape). 162known_browser(mozilla, netscape). 163known_browser(netscape, netscape). 164known_browser(konqueror, -). 165known_browser(opera, -). 166 167 168%! has_command(+Command) 169% 170% Succeeds if Command is in $PATH. Works for Unix systems. For 171% Windows we have to test for executable extensions. 172 173:- dynamic 174 command_cache/2. 175:- volatile 176 command_cache/2. 177 178has_command(Command) :- 179 command_cache(Command, Path), 180 !, 181 Path \== (-). 182has_command(Command) :- 183 ( getenv('PATH', Path), 184 ( current_prolog_flag(windows, true) 185 -> Sep = (;) 186 ; Sep = (:) 187 ), 188 atomic_list_concat(Parts, Sep, Path), 189 member(Part, Parts), 190 prolog_to_os_filename(PlPart, Part), 191 atomic_list_concat([PlPart, Command], /, Exe), 192 access_file(Exe, execute) 193 -> assert(command_cache(Command, Exe)) 194 ; assert(command_cache(Command, -)), 195 fail 196 ). 197 198 199 /******************************* 200 * NET PATHS * 201 *******************************/ 202 203%! url_path(+Alias, -Expansion) is nondet. 204% 205% Define URL path aliases. This multifile predicate is defined in 206% module =user=. Expansion is either a URL, or a term Alias(Sub). 207 208:- multifile 209 user:url_path/2. 210 211userurl_path(swipl, 'http://www.swi-prolog.org'). 212userurl_path(swipl_book, 'http://books.google.nl/books/about/\c 213 SWI_Prolog_Reference_Manual_6_2_2.html?\c 214 id=q6R3Q3B-VC4C&redir_esc=y'). 215 216userurl_path(swipl_faq, swipl('FAQ')). 217userurl_path(swipl_man, swipl('pldoc/doc_for?object=manual')). 218userurl_path(swipl_mail, swipl('Mailinglist.html')). 219userurl_path(swipl_download, swipl('Download.html')). 220userurl_path(swipl_pack, swipl('pack/list')). 221userurl_path(swipl_bugs, swipl('bugzilla/')). 222userurl_path(swipl_quick, swipl('man/quickstart.html')). 223 224%! expand_url_path(+Spec, -URL) 225% 226% Expand URL specifications similar to absolute_file_name/3. The 227% predicate url_path/2 plays the role of file_search_path/2. 228% 229% @error existence_error(url_path, Spec) if the location is not 230% defined. 231 232expand_url_path(URL, URL) :- 233 atomic(URL), 234 !. % Allow atom and string 235expand_url_path(Spec, URL) :- 236 Spec =.. [Path, Local], 237 ( user:url_path(Path, Spec2) 238 -> expand_url_path(Spec2, URL0), 239 ( Local == '.' 240 -> URL = URL0 241 ; sub_atom(Local, 0, _, _, #) 242 -> atom_concat(URL0, Local, URL) 243 ; atomic_list_concat([URL0, Local], /, URL) 244 ) 245 ; throw(error(existence_error(url_path, Path), expand_url_path/2)) 246 )