Введение
The socket extension implements a low-level interface to the socket
communication functions based on the popular BSD sockets, providing the
possibility to act as a socket server as well as a client.
For a more generic client-side socket interface, see
stream_socket_client(),
stream_socket_server(),
fsockopen(), and
pfsockopen().
When using these functions, it is important to remember that while
many of them have identical names to their C counterparts, they
often have different declarations. Please be sure to read the
descriptions to avoid confusion.
Those unfamiliar with socket programming can find a lot
of useful material in the appropriate Unix man pages, and there is a great
deal of tutorial information on socket programming in C on the web, much
of which can be applied, with slight modifications, to socket programming
in PHP. The » Unix Socket
FAQ might be a good start.