stream_set_timeout()

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

Set timeout period on a stream

说明

stream_set_timeout(resource $stream,int $seconds[,int $microseconds= 0]): bool

Sets the timeout value on$stream, expressed in the sum of$secondsand$microseconds.

When the stream times out, the 'timed_out' key of the array returned bystream_get_meta_data()is set toTRUE, although no error/warning is generated.

参数

$stream: The target stream.
$seconds: The seconds part of the timeout to be set.
$microseconds: The microseconds part of the timeout to be set.

返回值

成功时返回TRUE，或者在失败时返回FALSE。

范例

Example #1stream_set_timeout()example

<?php
$fp = fsockopen("www.example.com", 80);
if (!$fp) {
    echo "Unable to open\n";
} else {
    fwrite($fp, "GET / HTTP/1.0\r\n\r\n");
    stream_set_timeout($fp, 2);
    $res = fread($fp, 2000);
    $info = stream_get_meta_data($fp);
    fclose($fp);
    if ($info['timed_out']) {
        echo 'Connection timed out!';
    } else {
        echo $res;
    }
}
?>

注释

Note:
This function doesn't work with advanced operations likestream_socket_recvfrom(),usestream_select()with timeout parameter instead.

This function was previously called asset_socket_timeout()and latersocket_set_timeout()but this usage is deprecated.

参见

fsockopen() 打开一个网络连接或者一个Unix套接字连接
fopen() 打开文件或者 URL

In case anyone is puzzled, stream_set_timeout DOES NOT work for sockets created with socket_create or socket_accept. Use socket_set_option instead.
Instead of:
<?php
stream_set_timeout($socket,$sec,$usec);
?>
Use:
<?php
socket_set_option($socket, SOL_SOCKET, SO_RCVTIMEO, array('sec'=>$sec, 'usec'=>$usec));
socket_set_option($socket, SOL_SOCKET, SO_SNDTIMEO, array('sec'=>$sec, 'usec'=>$usec));
?>

If the timeout fails, because the server remains completely silent, one may have to add stream_select() to make the timeout work. This may be much more efficient that a non-blocking reading operation.
<?php
stream_set_timeout($c, $timeout);
$data = '';
$stR = array($this->smtp_conn);
$stW = null;
while (is_resource($c) && !feof($c)) {
  if (!stream_select($stR, $stW, $stW, $timeout)) {
    trigger_error('Timeout');
    break;
  }
  $str = fgets($c, 515);
  $data.= $str;
  // Handling of "traditional" timeout
  $info = stream_get_meta_data($c);
   if ($info['timed_out']) {
    trigger_error('Timeout');
    break;
  }
}
?>
Background: We had issues with a SMTP server that was addresses unencrypted while expecting TLS encryption. The stream_set_timeout() alone did not work as expected and the script hung for an hour or more.

Here is a working example for loops:
<?php
// Timeout in seconds
$timeout = 5;
$fp = fsockopen("www.server.com", 80, $errno, $errstr, $timeout);
if ($fp) {
    fwrite($fp, "GET /file.php HTTP/1.0\r\n");
    fwrite($fp, "Host: www.server.com\r\n");
    fwrite($fp, "Connection: Close\r\n\r\n");
    stream_set_blocking($fp, TRUE);
    stream_set_timeout($fp,$timeout);
    $info = stream_get_meta_data($fp);
    while ((!feof($fp)) && (!$info['timed_out'])) {
        $data .= fgets($fp, 4096);
        $info = stream_get_meta_data($fp);
        ob_flush;
        flush();
    }
    if ($info['timed_out']) {
        echo "Connection Timed Out!";
    } else {
        echo $data;
    }
}
?>

I didn't have much luck with the suggestions below (although I likely applied them wrong). 
Instead, I used stream_context_create() and set an http option for timeout. I fed that context into file_get_contents() and voila!
To my desperate friend below: the https transport can also use the http stream context options. I haven't verified this works as I don't have a slow responding ssl to test on. But if you are still stressing, give the below a shot (you may need to modify a bit...) 
<?php
  $timeout = 5*60;
  $options = array(
     'http'=>array(
      'method'=>"GET",
      'header'=>"Accept-language: en\r\n",
       'timeout' => $timeout 
       )
    );
  $context = stream_context_create($options);
  $contents = file_get_contents($source, false, $context);
?>
Yes...that is a 5 minute timeout.

Another note alread states that blocking-reads may be an issue, if the counterpart responds very slowly - or not at all. The stream timeout may not work as expected in such a situation.
However, php.net provides very little information on how to use non-blocking reading operations. Here's a code sample:
<?php
    stream_set_timeout($c, $timeout);
    $data = '';
    while (is_resource($c) && !feof($c)) {
      // Use non-blocking reading for first loop
      if (($data === '') and ($timeout > 0)) {
        stream_set_blocking($c, false);
        $endtimeOut = time() + $timeout;
        $str = '';
        while ((time() < $endtimeOut) and (strlen($str) < 515) and !feof($c)) {
          sleep(1); // Note: This may require tuning
          $str.= fgets($c, 515);
        }
        // Handling first-read timeout
        if (time() >= $endtimeOut) {
          trigger_error('Timeout', E_USER_WARNING);
          break;
        }
        stream_set_blocking($c, true);
      } else {
        $str = fgets($c, 515);
      }
      $data.= $str;
      // Handling of "traditional" timeout
      $info = stream_get_meta_data($c);
      if ($info['timed_out']) {
          trigger_error('Timeout', E_USER_WARNING);
          break;
      }
    }
?>

This function seems to have no effect when running as a CLI script, see http://bugs.php.net/bug.php?id=36030

If you are using fsockopen() to create a connection, first going to write into the stream and then waiting for the reply (e.g. simulating HTTP request with some extra headers), then stream_set_timeout() must be set only after the write - if it is before write, it has no effect on the read timeout :-( 
Noticed at least on PHP/4.3.10

stream_set_timeout() is not suitable for such files as UNIX-devices (/dev/...), i suggest to use select() instead with desirable timeout value - that works well.

I have found it required to add 
"stream_set_blocking($fp, FALSE )" 
prior to any fgets(), fread(), etc. to prevent the code from hanging up when remote files are called and the response is slow.

I have found that in order to actually stop the socket from timing out the script, you must call stream_get_meta_data and check for a timeout within the loop reading from the socket.
Example:
<?php
$sock = fsockopen($host, 80, $errno, $errstr, 30);
if(!$sock){
  echo "Unable to get server status";
}else{
  $out = "GET /server.php HTTP/1.1\r\n";
  $out .= "Host: $host\r\n";
  $out .= "Connection: Close\r\n\r\n";
  fwrite($sock, $out);
  stream_set_blocking($fp, FALSE );
  stream_set_timeout($sock, $timeout);
  $info = stream_get_meta_data($sock);
  while (!feof($sock) && !$info['timed_out']) {
    $file .= fgets($sock, 4096);
    $info = stream_get_meta_data($sock);
  }
  fclose($sock);
?>

Just in case someone stumbles into my situation... I was trying to get the microseconds part to work and it just wasn't working as expected.
Assuming blocking mode is true and I use 
<?php stream_set_timeout($s, 1, 0);?>
I get a 1s delay as expected. However when I do 
<?php stream_set_timeout($s, 0, 500);?>
I expect a 500microsecond delay but I get no delays at all. However when i do this
<?php stream_set_timeout($s, 0, 500000);?>
I get a 500 microsecond delay which is what I was expecting