YOURLS plugin: Public Prefix-N-Shorten

<?php
/*
Plugin Name: Public Prefix-N-Shorten
Plugin URI: http://yourls.org/
Description: Redirect "Prefix n' Shorten" bookmarklets to public interface
Version: 1.0
Author: Ozh
Author URI: http://ozh.org/
*/

// URL of your public interface, with query parameter to which the long URL will be passed
// This URL must contain a query string with "parameter equals %" (eg "url=%")
define( 'OZH_PUBPNF_URL', 'http://shor.rt/public.php?url=%' );

yourls_add_action( 'load_template_redirect_admin', 'ozh_pubpnf' );
function ozh_pubpnf( $args ) {
    // Long URL requested?
    $url = $args[0];

    // If logged in and don't want to change behavior for logged in users, do nothing
    if( yourls_is_valid_user() )
        return;

    // Otherwise, interrupt
    $redirect = str_replace( '%', rawurlencode( $url ), OZH_PUBPNF_URL );
    yourls_redirect( $redirect, 302 );
    die();
}


/**
Usage:

you must have a public interface up and running (for instance rename the provided sample public interface to public.php)

This public interface must accept a long URL as a query parameter (for instance 'url' as in
the sample provided). Edit OZH_PUBPNF_URL to reflect the public interface location and the parameter name.

**/