SPL Module Reference: socket

SPL Socket Module

This Module provides basic functions for handling TCP sockets.

builtin socket_create(host,port);
builtin socket_server(port);
builtin socket_accept(server);
builtin socket_write(socket,data);
builtin socket_poll(socket,timeout);
builtin socket_read(socket,length);
builtin socket_close();

object SocketEx { }

builtin socket_create(host,port);

Create an initial socket and connect to given host.
Returns the handle of the connected socket or 0 on failure.

builtin socket_server(port);

Establish a server socket; originally from bzs@bu-cs.bu.edu
The port number is the only parameter needed for this function.

Note that server sockets should not be used for read/write.
Rather use socket_accept(server) to accept incoming connections
that can be used for communication.

builtin socket_accept(server);

Accept incoming connections on a server socket.
Use socket_server(port) to create an initial server socket
that can accept incoming connection.

To determine if pending connections are available, use socket_poll(server).

builtin socket_write(socket,data);

Write data to given socket.
Note: can raise a SocketEx exception
Returns number of bytes written

builtin socket_poll(socket,timeout);

Poll socket for available data.
Returns 1 if bytes are available for non-blocking read, 0 otherwise.
On error, -1 is returned;

builtin socket_read(socket,length);

Read data from socket.
Note: can raise a SocketEx exception
Returns the string that was read

To achieve good read performance, it is suggested to use socket_poll() to
check if bytes are available for non-blocking read and to use
socket_read with a reasonably big buffer like 1000 bytes. The buffer
size is specified with the length parameter.

Available bytes are read into the buffer until the buffer is full or
no further data is available at that moment to avoid blocking.

Note: socket_read() will block until some data is available if there
      is no data available initially.

Note: Not tested with binary data. SPL is string oriented.

builtin socket_close();

Closes socket.

object SocketEx

SocketEx exception.
This can be thrown by read and write to signal an error.