Perform an HTTP request.

This is a flexible and powerful HTTP client implementation. Correctly handles GET, POST, PUT or any other HTTP requests. Handles redirects.

Parameters

$url: A string containing a fully qualified URI.

$headers: An array containing an HTTP header => value pair.

$method: A string defining the HTTP request to use.

$data: A string containing data to include in the request.

$retry: An integer representing how many times to retry the request in case of a redirect.

$timeout: A float representing the maximum number of seconds the function call may take. The default is 30 seconds. If a timeout occurs, the error code is set to the HTTP_REQUEST_TIMEOUT constant.

Return value

An object containing the HTTP request headers, response code, protocol, status message, headers, data and redirect status.

Related topics

File

drupal-6.x/includes/common.inc, line 455

Common functions that many Drupal modules will need to reference.

Code

function drupal_http_request($url, $headers = array(), $method = 'GET', $data = NULL, $retry = 3, $timeout = 30.0) {
  global $db_prefix;

  $result = new stdClass();

  // Parse the URL and make sure we can handle the schema.
  $uri = parse_url($url);

  if ($uri == FALSE) {
    $result->error = 'unable to parse URL';
    $result->code = -1001;
    return $result;
  }

  if (!isset($uri['scheme'])) {
    $result->error = 'missing schema';
    $result->code = -1002;
    return $result;
  }

  timer_start(__FUNCTION__);

  switch ($uri['scheme']) {
    case 'http':
    case 'feed':
      $port = isset($uri['port']) ? $uri['port'] : 80;
      $host = $uri['host'] . ($port != 80 ? ':' . $port : '');
      $fp = @fsockopen($uri['host'], $port, $errno, $errstr, $timeout);
      break;
    case 'https':
      // Note: Only works for PHP 4.3 compiled with OpenSSL.
      $port = isset($uri['port']) ? $uri['port'] : 443;
      $host = $uri['host'] . ($port != 443 ? ':' . $port : '');
      $fp = @fsockopen('ssl://' . $uri['host'], $port, $errno, $errstr, $timeout);
      break;
    default:
      $result->error = 'invalid schema ' . $uri['scheme'];
      $result->code = -1003;
      return $result;
  }

  // Make sure the socket opened properly.
  if (!$fp) {
    // When a network error occurs, we use a negative number so it does not
    // clash with the HTTP status codes.
    $result->code = -$errno;
    $result->error = trim($errstr);

    // Mark that this request failed. This will trigger a check of the web
    // server's ability to make outgoing HTTP requests the next time that
    // requirements checking is performed.
    // @see system_requirements()
    variable_set('drupal_http_request_fails', TRUE);

    return $result;
  }

  // Construct the path to act on.
  $path = isset($uri['path']) ? $uri['path'] : '/';
  if (isset($uri['query'])) {
    $path .= '?' . $uri['query'];
  }

  // Create HTTP request.
  $defaults = array(
    // RFC 2616: "non-standard ports MUST, default ports MAY be included".
    // We don't add the port to prevent from breaking rewrite rules checking the
    // host that do not take into account the port number.
    'Host' => "Host: $host",
    'User-Agent' => 'User-Agent: Drupal (+http://drupal.org/)',
  );

  // Only add Content-Length if we actually have any content or if it is a POST
  // or PUT request. Some non-standard servers get confused by Content-Length in
  // at least HEAD/GET requests, and Squid always requires Content-Length in
  // POST/PUT requests.
  $content_length = strlen($data);
  if ($content_length > 0 || $method == 'POST' || $method == 'PUT') {
    $defaults['Content-Length'] = 'Content-Length: ' . $content_length;
  }

  // If the server URL has a user then attempt to use basic authentication
  if (isset($uri['user'])) {
    $defaults['Authorization'] = 'Authorization: Basic ' . base64_encode($uri['user'] . (!empty($uri['pass']) ? ":" . $uri['pass'] : ''));
  }

  // If the database prefix is being used by SimpleTest to run the tests in a copied
  // database then set the user-agent header to the database prefix so that any
  // calls to other Drupal pages will run the SimpleTest prefixed database. The
  // user-agent is used to ensure that multiple testing sessions running at the
  // same time won't interfere with each other as they would if the database
  // prefix were stored statically in a file or database variable.
  if (is_string($db_prefix) && preg_match("/^simpletest\d+$/", $db_prefix, $matches)) {
    $defaults['User-Agent'] = 'User-Agent: ' . $matches[0];
  }

  foreach ($headers as $header => $value) {
    $defaults[$header] = $header . ': ' . $value;
  }

  $request = $method . ' ' . $path . " HTTP/1.0\r\n";
  $request .= implode("\r\n", $defaults);
  $request .= "\r\n\r\n";
  $request .= $data;

  $result->request = $request;

  // Calculate how much time is left of the original timeout value.
  $time_left = $timeout - timer_read(__FUNCTION__) / 1000;
  if ($time_left > 0) {
    stream_set_timeout($fp, floor($time_left), floor(1000000 * fmod($time_left, 1)));
    fwrite($fp, $request);
  }

  // Fetch response.
  $response = '';
  while (!feof($fp)) {
    // Calculate how much time is left of the original timeout value.
    $time_left = $timeout - timer_read(__FUNCTION__) / 1000;
    if ($time_left <= 0) {
      $result->code = HTTP_REQUEST_TIMEOUT;
      $result->error = 'request timed out';
      return $result;
    }
    stream_set_timeout($fp, floor($time_left), floor(1000000 * fmod($time_left, 1)));
    $chunk = fread($fp, 1024);
    $response .= $chunk;
  }
  fclose($fp);

  // Parse response headers from the response body.
  // Be tolerant of malformed HTTP responses that separate header and body with
  // \n\n or \r\r instead of \r\n\r\n.  See http://drupal.org/node/183435
  list($split, $result->data) = preg_split("/\r\n\r\n|\n\n|\r\r/", $response, 2);
  $split = preg_split("/\r\n|\n|\r/", $split);

  list($protocol, $code, $status_message) = explode(' ', trim(array_shift($split)), 3);
  $result->protocol = $protocol;
  $result->status_message = $status_message;

  $result->headers = array();

  // Parse headers.
  while ($line = trim(array_shift($split))) {
    list($header, $value) = explode(':', $line, 2);
    if (isset($result->headers[$header]) && $header == 'Set-Cookie') {
      // RFC 2109: the Set-Cookie response header comprises the token Set-
      // Cookie:, followed by a comma-separated list of one or more cookies.
      $result->headers[$header] .= ',' . trim($value);
    }
    else {
      $result->headers[$header] = trim($value);
    }
  }

  $responses = array(
    100 => 'Continue', 101 => 'Switching Protocols',
    200 => 'OK', 201 => 'Created', 202 => 'Accepted', 203 => 'Non-Authoritative Information', 204 => 'No Content', 205 => 'Reset Content', 206 => 'Partial Content',
    300 => 'Multiple Choices', 301 => 'Moved Permanently', 302 => 'Found', 303 => 'See Other', 304 => 'Not Modified', 305 => 'Use Proxy', 307 => 'Temporary Redirect',
    400 => 'Bad Request', 401 => 'Unauthorized', 402 => 'Payment Required', 403 => 'Forbidden', 404 => 'Not Found', 405 => 'Method Not Allowed', 406 => 'Not Acceptable', 407 => 'Proxy Authentication Required', 408 => 'Request Time-out', 409 => 'Conflict', 410 => 'Gone', 411 => 'Length Required', 412 => 'Precondition Failed', 413 => 'Request Entity Too Large', 414 => 'Request-URI Too Large', 415 => 'Unsupported Media Type', 416 => 'Requested range not satisfiable', 417 => 'Expectation Failed',
    500 => 'Internal Server Error', 501 => 'Not Implemented', 502 => 'Bad Gateway', 503 => 'Service Unavailable', 504 => 'Gateway Time-out', 505 => 'HTTP Version not supported'
  );
  // RFC 2616 states that all unknown HTTP codes must be treated the same as the
  // base code in their class.
  if (!isset($responses[$code])) {
    $code = floor($code / 100) * 100;
  }

  switch ($code) {
    case 200: // OK
    case 304: // Not modified
      break;
    case 301: // Moved permanently
    case 302: // Moved temporarily
    case 307: // Moved temporarily
      $location = $result->headers['Location'];
      $timeout -= timer_read(__FUNCTION__) / 1000;
      if ($timeout <= 0) {
        $result->code = HTTP_REQUEST_TIMEOUT;
        $result->error = 'request timed out';
      }
      elseif ($retry) {
        $result = drupal_http_request($result->headers['Location'], $headers, $method, $data, --$retry, $timeout);
        $result->redirect_code = $result->code;
      }
      $result->redirect_url = $location;

      break;
    default:
      $result->error = $status_message;
  }

  $result->code = $code;
  return $result;
}