A.30 library(www_browser): 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. Hand the URL to the desktop using desktop_open/2 from library(desktop) if this library is available. On Windows we use win_shell/2 if it is not.
3. If a environment variable BROWSER is set and this is the name of a known executable, use this.
4. Try to find a known browser.

[multifile]known_browser(+FileBaseName, -Compatible)

True if browser FileBaseName has a remote protocol compatible to Compatible.

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.

Errors

existence_error(url_path, Spec) if the location is not defined.