Reference Guide

ZCOM C I/F Library Routines
ZSET_RCVR (3X)
Chapter 4 321
ZSET_RCVR (3X)
NAME zset_rcvr – Set up program ZLU as message receiver for a terminal ZLU
SYNOPSIS
#include <zcom/zcomsys.h>
#include <zcom/zcomcall.h> /* if compiled with ANSI C (recommended) */
int32 zset_rcvr (action, zap, mode, rzap)
int action;
zaddr_type *zap;
uint32 mode;
zaddr_type *rzap;
DESCRIPTION The zset_rcvr() routine is used to establish where incoming data from a
terminal ZLU is to be queued. When zset_rcvr() is called, the rzap
parameter is used to supply the program ZLU to queue the data on.
(Note: An application’s program ZLU is returned by the zopen() routine.)
The type of data queued is selected using the mode parameter. You may
choose to receive data/status messages, and/or control messages. The
location (Virtual Circuit/device/terminal/etc) from which you want to
receive the data is specified by the zap parameter. An action parameter
value of ZcADD_PRIMARY sets the primary receiver.
Once you have called zset_rcvr(), the application program can issue
zread() requests to retrieve any data that may have arrived from the
selected terminal ZLU.
An application program that issues a zset_rcvr() call, as described above,
is the primary receiver of the specified messages. Another application
program can take over being the primary receiver by issuing a zset_rcvr()
request, using the same mode and rzap parameters, with the action code
also set to ZcADD_PRIMARY. In this situation, data is no longer queued
to the original application.
The zset_rcvr() routine can also be used to allow messages to be received
by more than one application program at a time. This feature is selected
by using an action parameter value of ZcADD_SHARED. When
ZcADD_SHARED is used, it specifies that the program does not want to
take over being the primary receiver, but simply added as an additional