Nice little string formatter

stringf.php

<?php

function stringf($template, array $vars=array())
{
    return preg_replace_callback(
        '/{{(\w+)}}/',
        function($match) use(&$vars) { return $vars[$match[1]]; }, 
        $template
    );
}

print stringf(
    'Hello, {{name}}. Today is {{day}}', 
    array(
        'name'=>'Alexandre', 
        'day'=> date('l')
    )
); //Hello, Alexandre. Today is Friday