CREATE.SERVER.SOCKET()

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The CREATE.SERVER.SOCKET() function creates a server socket on which a program may wait for incoming connections.

 

 

Format

 

CREATE.SERVER.SOCKET(addr, port, flags)

 

where

 

addris the address on which to listen for incoming connections. This may be an IP address or a host name. A null string implies listen on any local address.

 

portis the port number on which to listen for incoming connections.

 

flagsis a flag value formed from the additive values below. For compatibility with earlier releases, this may be omitted and defaults to a TCP stream connection. The token values are defined in the SYSCOM KEYS.H include record.

Socket type, one of:

SKT$STREAMA stream connection (default)
SKT$DGRMA datagram type connection

Protocol, one of:

SKT$TCPTransmission Control Protocol (default)
SKT$UDPUser Datagram Protocol

 

 

If the action is successful, this function returns the socket variable associated with the new server port and the STATUS() function returns zero.

 

If unsuccessful, the STATUS() function returns an error code that can be used to determine the cause of failure.

 

Use of CREATE.SERVER.SOCKET() within a phantom process makes that process consume a licence.

 

 

Example

 

SRVR.SKT = CREATE.SERVER.SOCKET("", 4000, SKT$STREAM + SKT$TCP)

IF STATUS() THEN STOP 'Cannot initialise server socket'

SKT = ACCEPT.SOCKET.CONNECTION(SRVR.SKT, 0)

IF STATUS() THEN STOP 'Error accepting connection'

DATA = READ.SOCKET(SKT, 100, SKT$BLOCKING, 0)

CLOSE.SOCKET SKT

CLOSE.SOCKET SRVR.SKT

 

This program fragment creates a server socket, waits for an incoming connection, reads a single data packet from this connection and then closes the sockets.

 

 

See also:

Using Socket Connections, ACCEPT.SOCKET.CONNECTION, CLOSE.SOCKET, OPEN.SOCKET(), READ.SOCKET(), SELECT.SOCKET(), SERVER.ADDR(), SET.SOCKET.MODE(), SOCKET.INFO(), WRITE.SOCKET()