stream_set_timeout(3) [php man page]
STREAM_SET_TIMEOUT(3) 1 STREAM_SET_TIMEOUT(3) stream_set_timeout - Set timeout period on a stream SYNOPSIS
bool stream_set_timeout (resource $stream, int $seconds, [int $microseconds]) DESCRIPTION
Sets the timeout value on $stream, expressed in the sum of $seconds and $microseconds. When the stream times out, the 'timed_out' key of the array returned by stream_get_meta_data(3) is set to TRUE, although no error/warning is generated. PARAMETERS
o $stream - The target stream. o $seconds - The seconds part of the timeout to be set. o $microseconds - The microseconds part of the timeout to be set. RETURN VALUES
Returns TRUE on success or FALSE on failure. CHANGELOG
+--------+---------------------------------------------------+ |Version | | | | | | | Description | | | | +--------+---------------------------------------------------+ | 4.3.0 | | | | | | | As of PHP 4.3, this function can (potentially) | | | work on any kind of stream. In PHP 4.3, socket | | | based streams are still the only kind supported | | | in the PHP core, although streams from other | | | extensions may support this function. | | | | +--------+---------------------------------------------------+ EXAMPLES
Example #1 stream_set_timeout(3) example <?php $fp = fsockopen("www.example.com", 80); if (!$fp) { echo "Unable to open "; } else { fwrite($fp, "GET / HTTP/1.0 "); stream_set_timeout($fp, 2); $res = fread($fp, 2000); $info = stream_get_meta_data($fp); fclose($fp); if ($info['timed_out']) { echo 'Connection timed out!'; } else { echo $res; } } ?> NOTES
Note This function doesn't work with advanced operations like stream_socket_recvfrom(3), use stream_select(3) with timeout parameter instead. This function was previously called as set_socket_timeout(3) and later socket_set_timeout(3) but this usage is deprecated. SEE ALSO
fsockopen(3), fopen(3). PHP Documentation Group STREAM_SET_TIMEOUT(3)
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STREAM_SELECT(3) 1 STREAM_SELECT(3) stream_select - Runs the equivalent of the select() system call on the given arrays of streams with a timeout specified by tv_sec and tv_usec SYNOPSIS
int stream_select (array &$read, array &$write, array &$except, int $tv_sec, [int $tv_usec]) DESCRIPTION
The stream_select(3) function accepts arrays of streams and waits for them to change status. Its operation is equivalent to that of the socket_select(3) function except in that it acts on streams. PARAMETERS
o $read - The streams listed in the $read array will be watched to see if characters become available for reading (more precisely, to see if a read will not block - in particular, a stream resource is also ready on end-of-file, in which case an fread(3) will return a zero length string). o $write - The streams listed in the $write array will be watched to see if a write will not block. o $except - The streams listed in the $except array will be watched for high priority exceptional ("out-of-band") data arriving. Note When stream_select(3) returns, the arrays $read, $write and $except are modified to indicate which stream resource(s) actu- ally changed status. You do not need to pass every array to stream_select(3). You can leave it out and use an empty array or NULL instead. Also do not forget that those arrays are passed by reference and will be modified after stream_select(3) returns. o $tv_sec - The $tv_sec and $tv_usec together form the timeout parameter, $tv_sec specifies the number of seconds while $tv_usec the number of microseconds. The $timeout is an upper bound on the amount of time that stream_select(3) will wait before it returns. If $tv_sec and $tv_usec are both set to 0, stream_select(3) will not wait for data - instead it will return immediately, indicating the current status of the streams. If $tv_sec is NULLstream_select(3) can block indefinitely, returning only when an event on one of the watched streams occurs (or if a signal interrupts the system call). Warning Using a timeout value of 0 allows you to instantaneously poll the status of the streams, however, it is NOT a good idea to use a 0 timeout value in a loop as it will cause your script to consume too much CPU time. It is much better to specify a timeout value of a few seconds, although if you need to be checking and running other code concurrently, using a timeout value of at least 200000 microseconds will help reduce the CPU usage of your script. Remember that the timeout value is the maximum time that will elapse; stream_select(3) will return as soon as the requested streams are ready for use. o $tv_usec - See $tv_sec description. RETURN VALUES
On success stream_select(3) returns the number of stream resources contained in the modified arrays, which may be zero if the timeout expires before anything interesting happens. On error FALSE is returned and a warning raised (this can happen if the system call is inter- rupted by an incoming signal). EXAMPLES
Example #1 stream_select(3) Example This example checks to see if data has arrived for reading on either $stream1 or $stream2. Since the timeout value is 0 it will return immediately: <?php /* Prepare the read array */ $read = array($stream1, $stream2); $write = NULL; $except = NULL; if (false === ($num_changed_streams = stream_select($read, $write, $except, 0))) { /* Error handling */ } elseif ($num_changed_streams > 0) { /* At least on one of the streams something interesting happened */ } ?> NOTES
Note Due to a limitation in the current Zend Engine it is not possible to pass a constant modifier like NULL directly as a parameter to a function which expects this parameter to be passed by reference. Instead use a temporary variable or an expression with the left- most member being a temporary variable: <?php $e = NULL; stream_select($r, $w, $e, 0); ?> Note Be sure to use the === operator when checking for an error. Since the stream_select(3) may return 0 the comparison with == would evaluate to TRUE: <?php $e = NULL; if (false === stream_select($r, $w, $e, 0)) { echo "stream_select() failed "; } ?> Note If you read/write to a stream returned in the arrays be aware that they do not necessarily read/write the full amount of data you have requested. Be prepared to even only be able to read/write a single byte. Note Some streams (like zlib) cannot be selected by this function. Note Windows compatibility: stream_select(3) used on a pipe returned from proc_open(3) may cause data loss under Windows 98. Use of stream_select(3) on file descriptors returned by proc_open(3) will fail and return FALSE under Windows. SEE ALSO
stream_set_blocking(3). PHP Documentation Group STREAM_SELECT(3)