cURL を使用して URL リダイレクトとページ移動エラーを処理する方法?

<code class="php">/**
 * Get a web file (HTML, XHTML, XML, image, etc.) from a URL.  Return an
 * array containing the HTTP server response header fields and content.
 */
function get_web_page( $url )
{
    $user_agent='Mozilla/5.0 (Windows NT 6.1; rv:8.0) Gecko/20100101 Firefox/8.0';

    $options = array(

        CURLOPT_CUSTOMREQUEST  => "GET",        // set request type post or get
        CURLOPT_POST           => false,        // set to GET
        CURLOPT_USERAGENT      => $user_agent, // set user agent
        CURLOPT_COOKIEFILE     => "cookie.txt", // set cookie file
        CURLOPT_COOKIEJAR      => "cookie.txt", // set cookie jar
        CURLOPT_RETURNTRANSFER => true,     // return web page
        CURLOPT_HEADER         => false,    // don't return headers
        CURLOPT_FOLLOWLOCATION => true,     // follow redirects
        CURLOPT_ENCODING       => "",       // handle all encodings
        CURLOPT_AUTOREFERER    => true,     // set referer on redirect
        CURLOPT_CONNECTTIMEOUT => 120,      // timeout on connect
        CURLOPT_TIMEOUT        => 120,      // timeout on response
        CURLOPT_MAXREDIRS      => 10,       // stop after 10 redirects
    );

    $ch      = curl_init( $url );
    curl_setopt_array( $ch, $options );
    $content = curl_exec( $ch );
    $err     = curl_errno( $ch );
    $errmsg  = curl_error( $ch );
    $header  = curl_getinfo( $ch );
    curl_close( $ch );

    $header['errno']   = $err;
    $header['errmsg']  = $errmsg;
    $header['content'] = $content;
    return $header;
}</code>

<code class="php">// Read a web page and check for errors:

$result = get_web_page( $url );

if ( $result['errno'] != 0 )
    ... error: bad url, timeout, redirect loop ...

if ( $result['http_code'] != 200 )
    ... error: no page, no permissions, no service ...

$page = $result['content'];</code>