stream_get_meta_data
(PHP 4 >= 4.3.0, PHP 5)
stream_get_meta_data — Retrieves header/meta data from streams/file pointers
Description
Returns information about an existing stream . The stream can be any stream created by fopen(), fsockopen() and pfsockopen(). The result array contains the following items:
-
timed_out (bool) - TRUE if the stream timed out while waiting for data on the last call to fread() or fgets().
-
blocked (bool) - TRUE if the stream is in blocking IO mode. See stream_set_blocking().
-
eof (bool) - TRUE if the stream has reached end-of-file. Note that for socket streams this member can be TRUE even when unread_bytes is non-zero. To determine if there is more data to be read, use feof() instead of reading this item.
-
unread_bytes (int) - the number of bytes currently contained in the PHP's own internal buffer.
Замечание: You shouldn't use this value in a script.
The following items were added in PHP 4.3.0:
-
stream_type (string) - a label describing the underlying implementation of the stream.
-
wrapper_type (string) - a label describing the protocol wrapper implementation layered over the stream. See List of Supported Protocols/Wrappers for more information about wrappers.
-
wrapper_data (mixed) - wrapper specific data attached to this stream. See List of Supported Protocols/Wrappers for more information about wrappers and their wrapper data.
-
filters (array) - and array containing the names of any filters that have been stacked onto this stream. Documentation on filters can be found in the Filters appendix.
Замечание: This function was introduced in PHP 4.3.0, but prior to this version, socket_get_status() could be used to retrieve the first four items, for socket based streams only.
In PHP 4.3.0 and later, socket_get_status() is an alias for this function.
Замечание: This function does NOT work on sockets created by the Socket extension.
The following items were added in PHP 5.0.0:
-
mode (string) - the type of access required for this stream (see Table 1 of the fopen() reference)
-
seekable (bool) - whether the current stream can be seeked.
-
uri (string) - the URI/filename associated with this stream.
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- stream_get_contents
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- stream_get_meta_data
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- stream_wrapper_restore
- stream_wrapper_unregister
Коментарии
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($modtime) : time();
}
here is just an example how to read out all meta data.
how ever I found out that the "seekable"-entry doesn't exist in most of the streaming media files.
if (!($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($fp);
In PHP 5.4.24 and 5.4.25, this command does not correctly return the stream blocking status. It always returns ['blocked'] == 1 regardless of the actual blocking mode. A call to stream_set_blocking($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.