A-Shell comes with a number of sample programs that can help you experiment with (or develop) client/server socket programs. The most general is tcptst.bp in EXLIB:[908,25], which interactively prompts you for each operation, and supports both client and server modes. EMAILX.BAS (included with the EMAILX developer’s toolkit) contains a fully functioning example of a client program communicating with an SMTP server. And the pair of rxcall.bas and rpcutl.bas contain a fully functioning example of both ends of a client/server connection using a custom protocolm, designed to send subroutine parameter information between machines to implement remote subroutines.