(PHP 4 >= 4.1.0, PHP 5, PHP 7)
socket_getpeername — Queries the remote side of the given socket which may either result in host/port or in a Unix filesystem path, dependent on its type
$socket
, string &$address
[, int &$port
] )Queries the remote side of the given socket which may either result in host/port or in a Unix filesystem path, dependent on its type.
socketA valid socket resource created with socket_create() or socket_accept().
address
If the given socket is of type AF_INET or
AF_INET6, socket_getpeername()
will return the peers (remote) IP address in
appropriate notation (e.g. 127.0.0.1 or
fe80::1) in the address
parameter and, if the optional port parameter is
present, also the associated port.
If the given socket is of type AF_UNIX,
socket_getpeername() will return the Unix filesystem
path (e.g. /var/run/daemon.sock) in the
address parameter.
port
If given, this will hold the port associated to
address.
Returns TRUE on success or FALSE on failure. socket_getpeername() may also return
FALSE if the socket type is not any of AF_INET,
AF_INET6, or AF_UNIX, in which
case the last socket error code is not updated.
Note:
socket_getpeername() should not be used with
AF_UNIXsockets created with socket_accept(). Only sockets created with socket_connect() or a primary server socket following a call to socket_bind() will return meaningful values.
Note:
For having socket_getpeername() to return a meaningful value, the socket it is applied upon must of course be one for which the concept of "peer" makes sense.
socket_getpeername will not work for UDP sockets. Instead, use socket_recvfrom - it provides the IP address and port of the source server - eg:
$size=socket_recvfrom($socket,$input,65535,0,$ipaddress,$port);
echo "Received [$input] ($size bytes) from IP $ipaddress Port $port\n";
The reason it won't work for UDP is that UDP is stateless; logically there are no peers other than at the time a packet is sent or received. Or more strictly, a UDP socket can interact with 0..N peers.
