stream_get_meta_data

(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)

stream_get_meta_data — 从流或文件指针中获取 header/meta 数据

说明

stream_get_meta_data(resource $stream): array

返回现有 stream 的有关信息。

参数

stream: 流可以是通过 fopen()、fsockopen()、 pfsockopen()、stream_socket_client() 创建的任何流。

返回值

返回的数组包含以下元素：

timed_out（bool）——如果流在最后调用 fread() 或 fgets() 时等待超时，则为 true。
blocked（bool）——如果流是堵塞 IO 模式，则为 true。参见 stream_set_blocking()。
eof（bool）——如果流已经到达文件结尾（end-of-file），则为 true。注意套接字流即使 unread_bytes 不为零也可以为 true。确定是否还可以读取更多数据，使用 feof() 而不是读取此值。
unread_bytes（int）——当前在 PHP 内部缓冲区的字节数。

注意: 不要在脚本中使用此值。
stream_type（string）——描述了流底层实现的标记。
wrapper_type（string）——描述了在流之上的协议封装实现的标记。更多关于封装协议的信息见支持的协议和封装协议。
wrapper_data（mixed）——当前流附加的封装协议数据。更多封装协议及其数据的信息见支持的协议和封装协议。
mode（string）——对当前流所要求的访问类型（见 fopen() 参考中的表格 1）。
seekable（bool）——是否可以在当前流中定位。
uri（string）——与当前流关联的 URI 或文件名。
crypto（array）——当前流的 TLS 连接元数据。（注意：仅在资源流使用 TLS 时提供。）

示例

示例 #1 stream_get_meta_data() 示例，fopen() 和 http 一起使用

<?php
$url = 'http://www.example.com/';

if (!$fp = fopen($url, 'r')) {
    trigger_error("Unable to open URL ($url)", E_USER_ERROR);
}

$meta = stream_get_meta_data($fp);

var_dump($meta);

fclose($fp);
?>

以上示例的输出类似于：

array(10) {
  'timed_out' =>
  bool(false)
  'blocked' =>
  bool(true)
  'eof' =>
  bool(false)
  'wrapper_data' =>
  array(13) {
    [0] =>
    string(15) "HTTP/1.1 200 OK"
    [1] =>
    string(11) "Age: 244629"
    [2] =>
    string(29) "Cache-Control: max-age=604800"
    [3] =>
    string(38) "Content-Type: text/html; charset=UTF-8"
    [4] =>
    string(35) "Date: Sat, 20 Nov 2021 18:17:57 GMT"
    [5] =>
    string(24) "Etag: "3147526947+ident""
    [6] =>
    string(38) "Expires: Sat, 27 Nov 2021 18:17:57 GMT"
    [7] =>
    string(44) "Last-Modified: Thu, 17 Oct 2019 07:18:26 GMT"
    [8] =>
    string(22) "Server: ECS (chb/0286)"
    [9] =>
    string(21) "Vary: Accept-Encoding"
    [10] =>
    string(12) "X-Cache: HIT"
    [11] =>
    string(20) "Content-Length: 1256"
    [12] =>
    string(17) "Connection: close"
  }
  'wrapper_type' =>
  string(4) "http"
  'stream_type' =>
  string(14) "tcp_socket/ssl"
  'mode' =>
  string(1) "r"
  'unread_bytes' =>
  int(1256)
  'seekable' =>
  bool(false)
  'uri' =>
  string(23) "http://www.example.com/"
}

示例 #2 stream_get_meta_data() 示例，stream_socket_client() 和 https 一起使用

<?php
$streamContext = stream_context_create(
    [
        'ssl' => [
            'capture_peer_cert' => true,
            'capture_peer_cert_chain' => true,
            'disable_compression' => true,
        ],
    ]
);

$client = stream_socket_client(
    'ssl://www.example.com:443',
    $errorNumber,
    $errorDescription,
    40,
    STREAM_CLIENT_CONNECT,
    $streamContext
);


$meta = stream_get_meta_data($client);

var_dump($meta);
?>

以上示例的输出类似于：

array(8) {
  'crypto' =>
  array(4) {
    'protocol' =>
    string(7) "TLSv1.3"
    'cipher_name' =>
    string(22) "TLS_AES_256_GCM_SHA384"
    'cipher_bits' =>
    int(256)
    'cipher_version' =>
    string(7) "TLSv1.3"
  }
  'timed_out' =>
  bool(false)
  'blocked' =>
  bool(true)
  'eof' =>
  bool(false)
  'stream_type' =>
  string(14) "tcp_socket/ssl"
  'mode' =>
  string(2) "r+"
  'unread_bytes' =>
  int(0)
  'seekable' =>
  bool(false)
}

注释

注意:
本函数对通过 Socket 扩展创建的套接字无效。

参见

get_headers() - 取得服务器响应 HTTP 请求所发送的所有标头
$http_response_header

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User Contributed Notes 4 notes

down

php dot chaska at xoxy dot net ¶

10 years ago

In PHP 5.4.24 and 5.4.25, this command does not correctly return the stream blocking status.  It always returns ['blocked'] == 1 regardless of the actual blocking mode.  A call to stream_set_blocking($stream, 0) will succeed (return TRUE) and subsequent calls to stream_get_contents($stream) will NOT block, even though a call to stream_get_meta_data($stream) will return 'blocked' == 1.  Hopefully this will save some people a bunch of debugging time.

See bug report #47918 for more information (http://bugs.php.net/bug.php?id=47918).

Proof:
<?php
$d = array(
    0 => array('pipe', 'r'),
    1 => array('pipe', 'w'),
    2 => array('file', 'error.log', 'a')
);

$p = proc_open('php -S localhost:8000', $d, $pipes);

if (!is_resource($p))   die("proc_open() failed\n");

// Set child's stdout pipe to non-blocking.
if (!stream_set_blocking($pipes[1], 0)) {
    die("stream_set_blocking() failed\n");
}
else {
    echo "Non-blocking mode should be set.\n";
}

// View the status of that same pipe.
// Note that 'blocked' is 1!  This appears to be wrong.
print_r(stream_get_meta_data($pipes[1]));

// Try to read something.  This will block if in blocking mode.
// If it does not block, stream_set_blocking() worked but
// stream_get_meta_data() is lying about blocking mode.
$data = stream_get_contents($pipes[1]);

echo "data = '$data'\n";
?>

Output:
Non-blocking mode should be set.
Array
(
    [stream_type] => STDIO
    [mode] => r
    [unread_bytes] => 0
    [seekable] =>
    [timed_out] =>
    [blocked] => 1         // << claims to be in blocking mode
    [eof] =>
)
data = ''                      // this would never appear if we blocked.

down

ed at readinged dot com ¶

21 years ago

Below is a function I wrote to pull the "Last-Modified" header from a given URL.  In PHP version 4.3 and above, it takes advantage of the stream_get_meta_data function, and in older version it uses a conventional GET procedure.  On failure to connect to $url, it returns NULL.  If the server does not return the Last-Modified header, it returns the current time.  All times are returned in PHP's integer format (seconds since epoch).

Use it as so:

$last_modified = stream_last_modified('http://www.php.net/news.rss');
if (!is_null($last_modified))
   if ($last_modified < time()-3600) //Older than an hour
      echo 'URL is older than an hour.';
   else
      echo 'URL is fairly new.';
else
   echo 'Invalid URL!';

function stream_last_modified($url)
{
   if (function_exists('version_compare') && version_compare(phpversion(), '4.3.0') > 0)
   {
      if (!($fp = @fopen($url, 'r')))
         return NULL;

      $meta = stream_get_meta_data($fp);
      for ($j = 0; isset($meta['wrapper_data'][$j]); $j++)
      {
         if (strstr(strtolower($meta['wrapper_data'][$j]), 'last-modified'))
         {
            $modtime = substr($meta['wrapper_data'][$j], 15);
            break;
         }
      }
      fclose($fp);
   }
   else
   {
      $parts = parse_url($url);
      $host  = $parts['host'];
      $path  = $parts['path'];

      if (!($fp = @fsockopen($host, 80)))
         return NULL;

      $req = "HEAD $path HTTP/1.0\r\nUser-Agent: PHP/".phpversion()."\r\nHost: $host:80\r\nAccept: */*\r\n\r\n";
      fputs($fp, $req);

      while (!feof($fp))
      {
         $str = fgets($fp, 4096);
         if (strstr(strtolower($str), 'last-modified'))
         {
            $modtime = substr($str, 15);
            break;
         }
      }
      fclose($fp);
  }
   return isset($modtime) ? strtotime($modtime) : time();
}

down

-1

niels at nise81 dot com ¶

16 years ago

here is just an example how to read out all meta data.
how ever I found out that the "seekable"-entry doesn't exist in most of the streaming media files.

      if (!($fp = @fopen($url, 'r')))
         return NULL;

      $meta = stream_get_meta_data($fp);
      
          foreach(array_keys($meta) as $h){
              $v = $meta[$h];
              echo "".$h.": ".$v."<br/>";
              if(is_array($v)){
                  foreach(array_keys($v) as $hh){
                      $vv = $v[$hh];
                      echo "_".$hh.": ".$vv."<br/>";
                  }
              }
          }
      fclose($fp);

down

-5

derkontrollfreak+9hy5l at gmail dot com ¶

9 years ago

Apparently, custom wrappers are always seekable.

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