\libdoc{www_browser}{Activating your Web-browser}

This library deals with the very system-dependent task of opening a
web page in a browser.  See also \pllib{url} and the HTTP package.

\begin{description}
    \predicate{www_open_url}{1}{+URL}
Open \arg{URL} in an external web browser. The reason to place this in
the library is to centralise the maintenance on this highly platform-
and browser-specific task.  It distinguishes between the following
cases:

\begin{itemlist}
    \item [MS-Windows]
If it detects MS-Windows it uses \index{win_shell/2}\predref{win_shell}{2} to open the \arg{URL}.  The
behaviour and browser started depends on the version of Windows and Windows-shell
configuration, but in general it should be the behaviour expected by
the user.

    \item [Other platforms]
On other platforms it tests the environment variable (see \index{getenv/2}\predref{getenv}{2})
named \env{BROWSER} or uses \program{netscape} if this variable is not
set.  If the browser is either \const{mozilla} or \const{netscape},
\index{www_open_url/1}\predref{www_open_url}{1} first tries to open a new window on a running browser using
the \const{-remote} option of Netscape.  If this fails or the browser
is not \const{mozilla} or \const{netscape} the system simply passes
the URL as first argument to the program.
\end{itemlist}
\end{description}

