ErnestMarples.com API consumer function

gistfile1.php

<?php

/**
 * This file contains a simple function for consuming the ErnestMarples.com postcode
 * geocoding API (http://ernestmarples.com/). The original function was written
 * by Stuart Harrison, I just adapted it to not rely on file_get_contents.
 *
 * @author Tom Graham (adapted from Stuart Harrison's function)
 * @link http://www.pezholio.co.uk/2009/07/ernest-marples-php-helper-function/
 */

/**
 * Returns the latitude/longitude coordinate for a given postcode using the
 * ErnestMarples.com API.
 * 
 * The result is returned as an array with the data in the following keys:
 *  0 => postcode
 *  1 => latitude coordinate
 *  2 => longitude coordinate
 * 
 * If the service is unresponsive or sends an invalid response then NULL will be 
 * returned.
 *
 * @param string $postcode 
 * @return array
 * @author Tom Graham
 */
function ernest_marples($postcode)
{
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, 'http://ernestmarples.com?f=csv&p=' . urlencode($postcode));
    curl_setopt($curl, CURLOPT_HEADER, false);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_TIMEOUT, 5);
    $response = curl_exec($curl);
    curl_close($curl);
    
    if (strpos($response, '<!DOCTYPE') !== false) {
        // Invalid postcode, HTML page returned
        return null;
    }
    
    $result = explode(',', $response);
    if (count($result) !== 3) {
        // Expected <postcode>,<latitude>,<longitude>
        return null;
    }
    
    return $result;
}