Reference Guide

ZCOM C I/F Library Routines
ZCNTL (3X)
Chapter 4170
ZCNTL (3X)
NAME zcntl – Send control message to terminal ZLU
SYNOPSIS
#include <zcom/zcomsys.h>
#include <zcom/zcomcall.h> /* if compiled with ANSI C (recommended) */
int32 zcntl (zap, mode, rcode, mhp, ibuf, len, rstat)
zaddr_type *zap;
uint32 mode;
uint32 rcode;
zmhd_type *mhp;
char *ibuf;
int32 len
int32 *rstat;
DESCRIPTION Routine zcntl is used to change the state of a terminal or to send a
protocol dependent control message to a terminal ZLU. The routine
zsend(3X) should be used for sending normal data messages to a
terminal.
The terminal must be disabled first if configuration parameters are to be
changed (e.g. rcode=6). As in zsend(3X), the mode parameter is used to
specify how the call should be completed and for selecting the priority of
the request. See under zsend(3X) for more information on its usage.
The response returned from zcntl is through the primary ZLU unless a
different source ZLU is specified in the header (mhp->mid.mzsrce).
Note that a program must call zopen() to allocate a primary or auxiliary
input ZLU before calling the zsend() routine. This must be done even if
the program does not need an input ZLU, for example, if it is not doing
any zread() calls and is only doing zsend() calls with mode =
ZcMODE_NO_WAIT (0) (send no-wait) where it does not care about the
return status.
The libraries libzcom_c.a and libpthread.a must be linked into the calling
program by giving the options “-lzcom_c -lpthread” to cc(1) or ld(1).