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:- autoload(library(lists),[member/2]). 41 42:- if(exists_source(library(process))). 43:- autoload(library(process), [process_create/3]). 44:- endif. 45 46:- multifile 47 known_browser/2. 48 49/** <module> Open a URL in the users browser 50 51This library deals with the highly platform specific task of opening a 52web page. In addition, is provides a mechanism similar to 53absolute_file_name/3 that expands compound terms to concrete URLs. For 54example, the SWI-Prolog home page can be opened using: 55 56 == 57 ?- www_open_url(swipl(.)). 58 == 59*/ 60 61%! www_open_url(+Url) 62% 63% Open URL in running version of the users' browser or start a new 64% browser. This predicate tries the following steps: 65% 66% 1. If a prolog flag (see set_prolog_flag/2) =browser= is set 67% and this is the name of a known executable, use this. The 68% flag may be set to `Command-Mode`, where mode is one of `fg` 69% or `bg`, requesting Command to run in foreground or background 70% mode. Default is `bg`. 71% 72% 2. On Windows, use win_shell(open, URL) 73% 74% 3. Find a generic `open' comment. Candidates are =xdg-open=, 75% =open= or =|gnome-open|=. 76% 77% 4. If a environment variable =BROWSER= is set 78% and this is the name of a known executable, use this. 79% 80% 5. Try to find a known browser. 81% 82% @tbd Figure out the right tool in step 3 as it is not 83% uncommon that multiple are installed. 84 85www_open_url(Spec) :- % user configured 86 expand_url_path(Spec, URL), 87 open_url(URL). 88 89open_url(URL) :- 90 current_prolog_flag(browser, Browser), 91 expand_browser_flag(Browser, Command, Mode), 92 has_command(Command), 93 !, 94 run_command(Command, [URL], Mode). 95:- if(current_predicate(win_shell/2)). 96open_url(URL) :- % Windows shell 97 win_shell(open, URL), 98 !. 99:- endif. 100open_url(URL) :- % Unix `open document' 101 open_command(Open), 102 has_command(Open), 103 !, 104 run_command(Open, [URL], fg). 105open_url(URL) :- % user configured 106 getenv('BROWSER', Browser), 107 has_command(Browser), 108 !, 109 run_browser(Browser, URL). 110open_url(URL) :- % something we know 111 known_browser(Browser, _), 112 has_command(Browser), 113 !, 114 run_browser(Browser, URL). 115 116expand_browser_flag(Command-Mode, Command, Mode) :- !. 117expand_browser_flag(Command, Command, bg) :- atomic(Command). 118 119open_command(open) :- % Apples open command 120 current_prolog_flag(apple, true). 121open_command('xdg-open'). % Free desktop 122open_command('gnome-open'). % Gnome (deprecated in favour of xdg-open 123open_command(open). % Who knows 124 125%! run_browser(+Browser, +URL) is det. 126% 127% Open a page using a browser. 128 129run_browser(Browser, URL) :- 130 run_command(Browser, [URL], bg). 131 132%! run_command(+Command, +Args, +Background) 133% 134% Run OS command Command using Args, silencing the error output 135% because many browsers are rather verbose. 136 137:- if(current_predicate(process_create/3)). 138run_command(Command, Args, fg) :- 139 !, 140 process_create(path(Command), Args, [stderr(null)]). 141:- endif. 142:- if(current_prolog_flag(unix, true)). 143run_command(Command, [Arg], fg) :- 144 format(string(Cmd), "\"~w\" \"~w\" &> /dev/null", [Command, Arg]), 145 shell(Cmd). 146run_command(Command, [Arg], bg) :- 147 format(string(Cmd), "\"~w\" \"~w\" &> /dev/null &", [Command, Arg]), 148 shell(Cmd). 149:- else. 150run_command(Command, [Arg], fg) :- 151 format(string(Cmd), "\"~w\" \"~w\"", [Command, Arg]), 152 shell(Cmd). 153run_command(Command, [Arg], bg) :- 154 format(string(Cmd), "\"~w\" \"~w\" &", [Command, Arg]), 155 shell(Cmd). 156:- endif. 157 158%! known_browser(+FileBaseName, -Compatible) 159% 160% True if browser FileBaseName has a remote protocol compatible to 161% Compatible. 162 163known_browser(firefox, netscape). 164known_browser(mozilla, netscape). 165known_browser(netscape, netscape). 166known_browser(konqueror, -). 167known_browser(opera, -). 168 169 170%! has_command(+Command) 171% 172% Succeeds if Command is in $PATH. Works for Unix systems. For 173% Windows we have to test for executable extensions. 174 175:- dynamic 176 command_cache/2. 177:- volatile 178 command_cache/2. 179 180has_command(Command) :- 181 command_cache(Command, Path), 182 !, 183 Path \== (-). 184has_command(Command) :- 185 ( getenv('PATH', Path), 186 ( current_prolog_flag(windows, true) 187 -> Sep = (;) 188 ; Sep = (:) 189 ), 190 atomic_list_concat(Parts, Sep, Path), 191 member(Part, Parts), 192 prolog_to_os_filename(PlPart, Part), 193 atomic_list_concat([PlPart, Command], /, Exe), 194 access_file(Exe, execute) 195 -> assert(command_cache(Command, Exe)) 196 ; assert(command_cache(Command, -)), 197 fail 198 ). 199 200 201 /******************************* 202 * NET PATHS * 203 *******************************/ 204 205%! url_path(+Alias, -Expansion) is nondet. 206% 207% Define URL path aliases. This multifile predicate is defined in 208% module =user=. Expansion is either a URL, or a term Alias(Sub). 209 210:- multifile 211 user:url_path/2. 212 213userurl_path(swipl, 'http://www.swi-prolog.org'). 214userurl_path(swipl_book, 'http://books.google.nl/books/about/\c 215 SWI_Prolog_Reference_Manual_6_2_2.html?\c 216 id=q6R3Q3B-VC4C&redir_esc=y'). 217 218userurl_path(swipl_faq, swipl('FAQ')). 219userurl_path(swipl_man, swipl('pldoc/doc_for?object=manual')). 220userurl_path(swipl_mail, swipl('Mailinglist.html')). 221userurl_path(swipl_download, swipl('Download.html')). 222userurl_path(swipl_pack, swipl('pack/list')). 223userurl_path(swipl_bugs, swipl('bug.html')). 224userurl_path(swipl_quick, swipl('man/quickstart.html')). 225 226%! expand_url_path(+Spec, -URL) 227% 228% Expand URL specifications similar to absolute_file_name/3. The 229% predicate url_path/2 plays the role of file_search_path/2. 230% 231% @error existence_error(url_path, Spec) if the location is not 232% defined. 233 234expand_url_path(URL, URL) :- 235 atomic(URL), 236 !. % Allow atom and string 237expand_url_path(Spec, URL) :- 238 Spec =.. [Path, Local], 239 ( user:url_path(Path, Spec2) 240 -> expand_url_path(Spec2, URL0), 241 ( Local == '.' 242 -> URL = URL0 243 ; sub_atom(Local, 0, _, _, #) 244 -> atom_concat(URL0, Local, URL) 245 ; sub_atom(URL0, 0, _, _, /) 246 -> absolute_file_name(Local, URL, [relative_to(URL0)]) 247 ; atomic_list_concat([URL0, Local], /, URL) 248 ) 249 ; throw(error(existence_error(url_path, Path), expand_url_path/2)) 250 )