socket_get_option
(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)
socket_get_option — Gets socket options for the socket
Description
The socket_get_option() function retrieves the value for
the option specified by the option
parameter for the
specified socket
.
Parameters
-
socket
-
A Socket instance 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, alevel
parameter ofSOL_SOCKET
would be used. Other levels, such asTCP
, can be used by specifying the protocol number of that level. Protocol numbers can be found by using the getprotobyname() function. -
option
-
Available Socket Options Option Description Type SO_DEBUG
Reports whether debugging information is being recorded. int SO_BROADCAST
Reports whether transmission of broadcast messages is supported. int SO_REUSEADDR
Reports whether local addresses can be reused. int SO_REUSEPORT
Reports whether local ports can be reused. int SO_KEEPALIVE
Reports whether connections are kept active with periodic transmission of messages. If the connected socket fails to respond to these messages, the connection is broken and processes writing to that socket are notified with a SIGPIPE signal. int SO_LINGER
Reports whether the
socket
lingers on socket_close() if data is present. By default, when the socket is closed, it attempts to send all unsent data. In the case of a connection-oriented socket, socket_close() will wait for its peer to acknowledge the data.If l_onoff is non-zero and l_linger is zero, all the unsent data will be discarded and RST (reset) is sent to the peer in the case of a connection-oriented socket.
On the other hand, if l_onoff is non-zero and l_linger is non-zero, socket_close() will block until all the data is sent or the time specified in l_linger elapses. If the socket is non-blocking, socket_close() will fail and return an error.
array. The array will contain two keys: l_onoff and l_linger. SO_OOBINLINE
Reports whether the socket
leaves out-of-band data inline.int SO_SNDBUF
Reports the size of the send buffer. int SO_RCVBUF
Reports the size of the receive buffer. int SO_ERROR
Reports information about error status and clears it. int (cannot be set by socket_set_option()) SO_TYPE
Reports the socket
type (e.g.SOCK_STREAM
).int (cannot be set by socket_set_option()) SO_DONTROUTE
Reports whether outgoing messages bypass the standard routing facilities. int SO_RCVLOWAT
Reports the minimum number of bytes to process for socket
input operations.int SO_RCVTIMEO
Reports the timeout value for input operations. array. The array will contain two keys: sec which is the seconds part on the timeout value and usec which is the microsecond part of the timeout value. SO_SNDTIMEO
Reports the timeout value specifying the amount of time that an output function blocks because flow control prevents data from being sent. array. The array will contain two keys: sec which is the seconds part on the timeout value and usec which is the microsecond part of the timeout value. SO_SNDLOWAT
Reports the minimum number of bytes to process for socket
output operations.int TCP_NODELAY
Reports whether the Nagle TCP algorithm is disabled. int MCAST_JOIN_GROUP
Joins a multicast group. array with keys "group"
, specifying a string with an IPv4 or IPv6 multicast address and"interface"
, specifying either an interface number (type int) or astring
with the interface name, like"eth0"
.0
can be specified to indicate the interface should be selected using routing rules. (can only be used in socket_set_option())MCAST_LEAVE_GROUP
Leaves a multicast group. array. See MCAST_JOIN_GROUP
for more information. (can only be used in socket_set_option())MCAST_BLOCK_SOURCE
Blocks packets arriving from a specific source to a specific multicast group, which must have been previously joined. array with the same keys as MCAST_JOIN_GROUP
, plus one extra key,source
, which maps to a string specifying an IPv4 or IPv6 address of the source to be blocked. (can only be used in socket_set_option())MCAST_UNBLOCK_SOURCE
Unblocks (start receiving again) packets arriving from a specific source address to a specific multicast group, which must have been previously joined. array with the same format as MCAST_BLOCK_SOURCE
. (can only be used in socket_set_option())MCAST_JOIN_SOURCE_GROUP
Receive packets destined to a specific multicast group whose source address matches a specific value. array with the same format as MCAST_BLOCK_SOURCE
. (can only be used in socket_set_option())MCAST_LEAVE_SOURCE_GROUP
Stop receiving packets destined to a specific multicast group whose source address matches a specific value. array with the same format as MCAST_BLOCK_SOURCE
. (can only be used in socket_set_option())IP_MULTICAST_IF
The outgoing interface for IPv4 multicast packets. Either int specifying the interface number or a string with an interface name, like eth0
. The value 0 can be used to indicate the routing table is to used in the interface selection. The function socket_get_option() returns an interface index. Note that, unlike the C API, this option does NOT take an IP address. This eliminates the interface difference betweenIP_MULTICAST_IF
andIPV6_MULTICAST_IF
.IPV6_MULTICAST_IF
The outgoing interface for IPv6 multicast packets. The same as IP_MULTICAST_IF
.IP_MULTICAST_LOOP
The multicast loopback policy for IPv4 packets, which determines whether multicast packets sent by this socket also reach receivers in the same host that have joined the same multicast group on the outgoing interface used by this socket. This is the case by default. int (either 0
or1
). For socket_set_option() any value will be accepted and will be converted to a boolean following the usual PHP rules.IPV6_MULTICAST_LOOP
Analogous to IP_MULTICAST_LOOP
, but for IPv6.int. See IP_MULTICAST_LOOP
.IP_MULTICAST_TTL
The time-to-live of outgoing IPv4 multicast packets. This should be a value between 0 (don't leave the interface) and 255. The default value is 1 (only the local network is reached). int between 0 and 255. IPV6_MULTICAST_HOPS
Analogous to IP_MULTICAST_TTL
, but for IPv6 packets. The value -1 is also accepted, meaning the route default should be used.int between -1 and 255. SO_MARK
Sets an identifier on the socket for packet filtering purpose on Linux. int SO_ACCEPTFILTER
Adds an accept filter on the listened socket (FreeBSD/NetBSD). An accept filter kernel module needs to be loaded beforehand on FreeBSD (e.g. accf_http). string name of the filter (length 15 max). SO_USER_COOKIE
Sets an identifier on the socket for packet filtering purpose on FreeBSD. int SO_DONTTRUNC
Retain unread data. int SO_WANTMORE
Give a hint when more data is ready. int TCP_DEFER_ACCEPT
Don't notify a listening socket until data is ready. int
Return Values
Returns the value of the given option, or false
on failure.
Changelog
Version | Description |
---|---|
8.0.0 |
socket is a Socket instance now;
previously, it was a resource.
|
Examples
Example #1 socket_get_option() example
<?php
$socket = socket_create_listen(1223);
$linger = array('l_linger' => 1, 'l_onoff' => 1);
socket_set_option($socket, SOL_SOCKET, SO_LINGER, $linger);
var_dump(socket_get_option($socket, SOL_SOCKET, SO_REUSEADDR));
?>
See Also
- socket_create_listen() - Opens a socket on port to accept connections
- socket_set_option() - Sets socket options for the socket