Greasemonkey to redirect site URLs from .html to -print.html?

Question

Need help making a script for Greasemonkey that will help me read forums more efficiently.

Redirect all pages ending in .html:

http://www.site.com/thread-category/4525-url.html

To this printable version URL:

http://www.site.com/thread-category/4525-url-print.html

(Add -print, just before ending .html.

Answer 1

To do this accounting for possible URL parameters and hash tags:

// ==UserScript==
// @name     _Redirect site.com to print.html URL's
// @include  /site\.com\/thread.+?\.html\b/
// @grant    none   
// @run-at   document-start
// ==/UserScript==

if ( ! /print\.html$/i.test (location.pathname) ) {
    var printPath   = location.pathname.replace (/(\.html)$/, "-print$1");
    var newURL      = location.protocol + "//"
                    + location.host
                    + printPath
                    + location.search
                    + location.hash
                    ;
    location.replace (newURL);
}

Note that we use the regex version of @include.