The PHP Function Socket_Close
The php function socket_close closes the socket resource created by socket_create() or socket_bind(). This function is used to terminate the connection between the client and server once the communication has been completed.
Sockets are mainly used for Interprocess communication between two processes. This is done in the client-server model where the client sends a request to the server and the server gives the response back to the client. The pfsockopen() function in PHP provides the functionality to establish such a persistent socket connection between your PHP script and a remote server.
To begin with the sockets programming, you need to create a socket using the socket_create() function and then bind it to the IP address and port number of your server itself. The function also allows you to specify the protocol type, which can be either AF_INET or SOCK_STREAM.
Once the socket is created and bound, it can be waited for incoming connections using the socket_listen() function. When a connection is accepted, the server program reads the request from the client socket using the socket_read() function and then writes the response to the client with the socket_write() function.
Note that the server program must have the same socket as the client, so the ip address and port number of the server must be identical to that of the client. Also, the incoming data sent from the client must have a terminating character such as a tab (
