StringsInPHP - //Problem 4. Extract all valid URLs

//Problem 4.    Extract all valid URLs
//Write a regex pattern for extracting all URL’s addresses from given text.
//Hint: http://en.wikipedia.org/wiki/Uniform_resource_locator

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
        <form method="post" action="ExtractValidURLS.php">
            <input type="text" name="str1">
            <input type="submit" value="GO">
        </form>
    </body>
</html>

<?php
$string = $_POST['str1'];//"Hello https://www.bytes.com world ftp://www.yahoo.com http://www.yahoo.com/asd/asd";
preg_match_all('/((([A-Za-z]{3,9}:(?:\/\/)?)'
        . '(?:[-;:&=\+\$,\w]+@)?[A-Za-z0-9.-'
        . ']+|(?:www.|[-;:&=\+\$,\w]+@)[A-Za'
        . '-z0-9.-]+)((?:\/[\+~%\/.\w-_]*)?'
        . '\??(?:[-\+=&;%@.\w_]*)#?(?:[\w]*'
        . '))?)/', $string, $text);
echo '<pre>' . print_r($text[0], true) . '</pre>';
?>