Extracts any one URL in the given string and assigns it to a variable.

url_matcher.php

<?php
    $new_entry['url'] = FALSE;
    $new_entry['description'] = 'Hello there! example.com';

    $pattern_url = "`("
        . "(https?://)?"
        . "([a-z\d-]+\.)+"
        . "(MUSEUM|TRAVEL|AERO|ARPA|ASIA|EDU|GOV|MIL|MOBI|COOP|INFO|NAME|BIZ|CAT|COM|INT|JOBS|NET|ORG|PRO|TEL|A[CDEFGILMNOQRSTUWXZ]|B[ABDEFGHIJLMNORSTVWYZ]|C[ACDFGHIKLMNORUVXYZ]|D[EJKMOZ]|E[CEGHRSTU]|F[IJKMOR]|G[ABDEFGHILMNPQRSTUWY]|H[KMNRTU]|I[DELMNOQRST]|J[EMOP]|K[EGHIMNPRWYZ]|L[ABCIKRSTUVY]|M[ACDEFGHKLMNOPQRSTUVWXYZ]|N[ACEFGILOPRUZ]|OM|P[AEFGHKLMNRSTWY]|QA|R[EOSUW]|S[ABCDEGHIJKLMNORTUVYZ]|T[CDFGHJKLMNOPRTVWZ]|U[AGKMSYZ]|V[ACEGINU]|W[FS]|Y[ETU]|Z[AMW])+"
        . "(:\d+)?"
        . "((/([a-z0-9\._/~%\-\+&\#\?!=\(\)@]+)?)*)"
        . ")`i";

    if ( preg_match( $pattern_url, $new_entry['description'], $match ) ) {

        $url = $match[0];

        if ( FALSE === strpos($url, '://') ) {
            $url = 'http://' . $url;
        }

        $new_entry['url'] = htmlspecialchars( $url );
        $new_entry['description'] = str_replace( $match[0], '', $new_entry['description'] );
    }

    echo $new_entry['description'];
    echo $new_entry['url'] ? ' url: '.$new_entry['url'] : '';
?>