HP Advanced Communications Controllers (ACC) manual Zpeek

ZCOM C I/F Library Routines

ZPEEK (3X)

		ZPEEK (3X)
NAME		zpeek – Read data from ZLU without disturbing input queue
SYNOPSIS
#include	<zcom/zcomsys.h>
#include	<zcom/zcomcall.h> /* if compiled with ANSI C (recommended) */
int32 zpeek (zap, mode, mhp, ibuf, len, rlen, rstat)
zaddr_type		*zap;
uint32		mode;
zmhd_type		*mhp;
char		*ibuf;
int32		len;
int32		*rlen;
int32		*rstat;
DESCRIPTION		Routine zpeek fetches the next message from the head of a program ZLU
		input queue. The program has the option to wait (i.e. suspend) if there is
		no data on the queue specified. The actual length of the data message is
		returned in rlen.

zpeek is similar to zread(3X) except that it does not remove the message after retrieving it. Multiple calls to zpeek on the same ZLU will return the same message until zread(3X) is called, i.e. it can only look at the first message on the input queue. In addition, the automatic response mechanism is not triggered when fetching a message by zpeek, i.e. no response will be sent to the message sender until the message is removed from the input queue with zread.

The zpeek routine has identical parameters to the zread routine. See the zread routine for a description of the parameters.

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).

274 Chapter 4