Rewriting HTTP requests

It's sometime necessary to rewrite an HTTP request for one file into another file. For example, part of the content on a website may have been moved, but clients may have cached or bookmarked the old links. Alternatively, a legacy component of a website may use a different URL space to identify resources.

# rewrite all requests for content in /graphics to /images instead

$url = http.getPath();
if( string.startsWith( $url, "/graphics/" ) ) {
   $newurl = string.regexsub( $url, "^/graphics/", "/images/" );
   http.setPath( $newurl );
}

The above example uses a regular expression substitution to change "/graphics/" to "/images/" in the URL. There are many other ways to manipulate strings; for example, the string.skip() function can remove the 10-character "/graphics/" prefix from the start of the string:

   $newurl = "/images/" . string.skip( $url, 10 );

Owen Garrett [Zeus Dev Team] 01 July 2005