flush_rewrite_rules.php

<?php
/**
 * Validat the last Modifikation of this File
 * on modification flush the rewrite rules
 *
 * @return void
 */

function flush_rules() {

    $o 	= 'my-custom-flash-key';
    $v	= filemtime( __FILE__ );
    $d 	= array( 'version' => 0, 'time' => time() );
    $r 	= wp_parse_args( get_option( $o, array() ), $d );

    if ( $r['version'] != $v ) { 

        flush_rewrite_rules();
		
	$a = array( 'version' => $v, 'time' => time() );
		
	if ( ! update_option( $o , $a ) ) {
		add_option( $o , $a );
        }
     }
}