Is valid URL function

is-valid-url.php

<?php

/**
* Test if URL is valid
* @author SpikeZ
* @param string $str
* @return bool
*/

function is_valid_url ($uri)
{

    if (preg_match( '/^(http|https):\\/\\/[a-z0-9_]+([\\-\\.]{1}[a-z_0-9]+)*\\.[_a-z]{2,5}'.'((:[0-9]{1,5})?\\/.*)?$/i' ,$uri))
      return $uri;

    return false;

}