Drupal爱好者

drupal函数drupal_http_request是一个不太经常用到的函数。

下面把这个函数的使用介绍一下：

drupal_http_request($url, $headers = array(), $method = 'GET', $data =
NULL, $retry = 3)

函数作用：执行一个http请求。这是一个灵活并且强大的客户端执行函数。目前能够处理GET, POST, PUT或其他的HTTP请求。使其可以重新定向。

参数说明：

$url 包含完整的URI的字符串。

$headers 包含HTTP的header => value对的一个数组。

$method HTTP请求的方式。

$data 在请求中包含的数据。

$retry 请求次数。

返回值：

返回一个对象，这个对象包括了HTTP请求的头,请求返回状态代码, 文件头, 请求包含的数据,
和跳转状态。

具体的代码如下：

<?php
function drupal_http_request($url, $headers = array(), $method = 'GET', $data = NULL, $retry = 3) {
  $result = new stdClass();

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

  switch ($uri['scheme']) {
    case 'http':
      $port = isset($uri['port']) ? $uri['port'] : 80;
      $host = $uri['host'] . ($port != 80 ? ':'. $port : '');
      $fp = @fsockopen($uri['host'], $port, $errno, $errstr, 15);
      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, 20);
      break;
    default:
      $result->error = 'invalid schema '. $uri['scheme'];
      return $result;
  }

  // Make sure the socket opened properly.
  if (!$fp) {
    $result->error = trim($errno .' '. $errstr);
    $result->code = -$errno;
    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: $host",
    'User-Agent' => 'User-Agent: Drupal (+http://drupal.org/)',
    'Content-Length' => 'Content-Length: '. strlen($data)
  );

  // 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'] : ''));
  }

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

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

";
  if ($data) {
    $request .= $data ."
";
  }
  $result->request = $request;

  fwrite($fp, $request);

  // Fetch response.
  $response = '';
  while (!feof($fp) && $chunk = fread($fp, 1024)) {
    $response .= $chunk;
  }
  fclose($fp);

  // Parse response.
  list($split, $result->data) = explode("

", $response, 2);
  $split = preg_split("/
|
|
/", $split);

  list($protocol, $code, $text) = explode(' ', trim(array_shift($split)), 3);
  $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'];

      if ($retry) {
        $result = drupal_http_request($result->headers['Location'], $headers, $method, $data, --$retry);
        $result->redirect_code = $result->code;
      }
      $result->redirect_url = $location;

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

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