Function interp_close_socket 

fn interp_close_socket(
    args: &[RValue],
    named: &[(String, RValue)],
    context: &BuiltinContext<'_>,
) -> Result<RValue, RError>

Close a TCP socket connection.

Shuts down the TCP stream and removes it from the connection table. Returns invisible NULL. This is the socket-specific close — the generic close() also handles TCP sockets.

@param socket integer scalar: connection ID of a TCP socket @return NULL (invisibly)