(PHP 4 >= 4.3.0, PHP 5, PHP 7)
socket_set_option — Sets socket options for the socket
The socket_set_option() function sets the option
specified by the optname parameter, at the
specified protocol level, to the value pointed to
by the optval parameter for the
socket.
socketA valid socket resource created with socket_create() or socket_accept().
level
The level parameter specifies the protocol
level at which the option resides. For example, to retrieve options at
the socket level, a level parameter of
SOL_SOCKET would be used. Other levels, such as
TCP, can be used by specifying the protocol number of that level.
Protocol numbers can be found by using the
getprotobyname() function.
optnameThe available socket options are the same as those for the socket_get_option() function.
optvalThe option value.
Returns TRUE on success or FALSE on failure.
Example #1 socket_set_option() example
<?php
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
if (!is_resource($socket)) {
echo 'Unable to create socket: '. socket_strerror(socket_last_error()) . PHP_EOL;
}
if (!socket_set_option($socket, SOL_SOCKET, SO_REUSEADDR, 1)) {
echo 'Unable to set option on socket: '. socket_strerror(socket_last_error()) . PHP_EOL;
}
if (!socket_bind($socket, '127.0.0.1', 1223)) {
echo 'Unable to bind socket: '. socket_strerror(socket_last_error()) . PHP_EOL;
}
$rval = socket_get_option($socket, SOL_SOCKET, SO_REUSEADDR);
if ($rval === false) {
echo 'Unable to get socket option: '. socket_strerror(socket_last_error()) . PHP_EOL;
} else if ($rval !== 0) {
echo 'SO_REUSEADDR is set on socket !' . PHP_EOL;
}
?>
Setting the socket timeout microseconds ('usec') does not work under Windows, at least under PHP/5.2.9:
<?php
$timeout = array('sec'=>1,'usec'=>500000);
socket_set_option($socket,SOL_SOCKET,SO_RCVTIMEO,$timeout);
var_dump(socket_set_option($socket,SOL_SOCKET,SO_RCVTIMEO));
?>
Output on Windows box:
array(2) {
["sec"]=>
int(1)
["usec"]=>
int(0)
}
Output on Linux box:
array(2) {
["sec"]=>
int(1)
["usec"]=>
int(500000)
}
To expand a bit more on what "tim at e2-media dot co dot nz" started.
SO_SNDTIMEO is one of the many constants you can use with socket_set_option.
See http://ca.php.net/manual/en/ref.sockets.php for the available Predefind Constants and visit http://man.he.net/man2/setsockopt for the meaning of the ones relevant.
Tim's example might seem at first a bit non-intuitive since he is using the SO_SNDTIMEO constant. Which means, if the socket has to send out data, it must do it within the limit specified - in his case 10 seconds. Usually you won't set a timeout for sending out data. Nevertheless, the example is valid, and there are situations where you need to do so.
A more intuitive use of socket_set_option would be to set a time out for a blocking socket (a socket that waits for data to be receive when read from). You would do this like so:
socket_set_option($socket,SOL_SOCKET, SO_RCVTIMEO, array("sec"=>0, "usec"=>100));
Notice that sec= 0 and usec= 100; Depending on how long you want your program to wait to recieve data, you might want to change these values.
Regards,
drenintell
I would like to comment on the previous note regarding blocking sockets.
There is more to blocking sockets than waiting for data to be received when trying to be read upon, just to make example, a listening blocking socket will wait for a client to try to connect before it returns when you socket_accept() it.
To set a socket timeout value (assuming you've set it blocking) use:
socket_set_option(
$socket,
SOL_SOCKET, // socket level
SO_SNDTIMEO, // timeout option
array(
"sec"=>10, // Timeout in seconds
"usec"=>0 // I assume timeout in microseconds
)
);
Lingering will sometimes not work when you're working with non-blocking sockets. Even if the socket is set to linger and you keep tying to close until the socket doesn't return an error and the resource is no longer identifiable as type 'Socket', the socket may STILL close without sending everything.
Therefore, in the event that you are using non-blocking sockets (which is preferable if you care at all about signaling), you should set the socket as blocking (socket_set_block()) before calling to close it. This will allow everything to flush before it returns.
Dustin Oprea
It appears that Winsock does not acknowledge timeout (send and receive) on Windows.
