Userscripts.org

// Offsite Blank
// version 0.5 BETA!
// 2005-07-08
//
// --------------------------------------------------------------------
//
// This is a Greasemonkey user script that forces offsite links to
// open in a new window.
//
// To install, you need Greasemonkey: http://greasemonkey.mozdev.org/
// Then restart Firefox and revisit this script.
// Under Tools, there will be a new menu item to "Install User Script".
// Accept the default configuration and install.
//
// To uninstall, go to Tools/Manage User Scripts,
// select "Offsite Blank", and click Uninstall.
//
// --------------------------------------------------------------------
//
// ==UserScript==
// @name          Offsite Blank
// @namespace     http://diveintomark.org/projects/greasemonkey/
// @description   force offsite links to open in a new window
// @include       *
// ==/UserScript==

/* BEGIN LICENSE BLOCK
Copyright (C) 2005 Mark Pilgrim

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You can download a copy of the GNU General Public License at
http://diveintomark.org/projects/greasemonkey/COPYING
or get a free printed copy by writing to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
END LICENSE BLOCK */

(function() {
    function getCurrentDomain() {
        var href = window.location.href;
        return href.replace(/^.*?\/\/(.*?)\/.*$/, '$1');
    }

    function getOffsiteLinks() {
        var a, i, offsite, thisdomain, href, links;
        offsite = new Array();
        thisdomain = getCurrentDomain().toLowerCase();
        if (!thisdomain) { return offsite; }
        links = document.evaluate(
            "//a[starts-with(@href, 'http://')]",
            document,
            null,
            XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE,
            null);
        for (i = 0; i < links.snapshotLength; i += 1) {
            a = links.snapshotItem(i);
            href = a.href.replace(/^.*?\/\/(.*)$/, '$1');
            if (href.toLowerCase().indexOf(thisdomain) !== 0) {
                offsite.push(a);
            }
        }
        return offsite;
    }

    var offsitelinks, i;
    offsitelinks = getOffsiteLinks();
    for (i in offsitelinks) {
        offsitelinks[i].target = "_blank";
    }
})();
//
// ChangeLog
// 2005-07-08 - 0.5 - MAP - added license block
// 2005-04-21 - 0.4 - MAP - linted
// 2005-04-21 - 0.3 - MAP - use simpler function syntax
// 2005-04-18 - 0.2 - MAP - tidy code
//