XCode generate xib files from strings files with translation

build_xibs.php

#!/usr/bin/php
<?
/**
 * @license MIT
 */
$target='de.lproj';
$source='en.lproj';
$handle = opendir('de.lproj');

while (false !== ($file = readdir($handle))) {
    if (substr($file,-8)==".strings") {
        $file_name=substr($file,0,-8);
        $strings_file=$target.'/'.$file;
        $target_xib=$target.'/'.$file_name.'.xib';
        $source_xib=$source.'/'.$file_name.'.xib';
        if (file_exists($source_xib)) {
            $target_modified=0;
            $strings_modified = filemtime($strings_file); 
            if (file_exists($target_xib)) {
                $target_modified = filemtime($target_xib);
            }
            if ($target_modified<$strings_modified) {
                $command=sprintf('ibtool --strings-file "%s" --write "%s" "%s"',$strings_file, $target_xib, $source_xib);
                echo "Building $target_xib! \n";
                exec($command);
            } else {
                echo "Skipping $target_xib! \n";
            }
        }
        //echo $command."\n\n";
    }
}