From owner-freebsd-hackers  Fri Dec 22 06:14:11 1995
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Date: Fri, 22 Dec 1995 09:14:02 -0500
From: tsingle@sunland.gsfc.nasa.gov (Tim Singletary)
Message-Id: <199512221414.JAA07674@sunland.gsfc.nasa.gov>
To: hackers@freebsd.org
Subject: Re: semctl() portability issue and fix
Sender: owner-hackers@freebsd.org
Precedence: bulk

I inadvertently inserted the wrong version of semctl() in my previous
version.  What I'm actually using is:

-begin--------------
#include <stdarg.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
    
int semctl(int semid, int semnum, int cmd, ...)
{
    va_list ap;
    union semun fourth_arg;
    union semun *fourth_arg_ptr;

    va_start(ap,cmd);
    if (cmd == IPC_SET || cmd == IPC_STAT || cmd == GETALL
                                    || cmd == SETVAL || cmd == SETALL) {
        fourth_arg = va_arg(ap, union semun);
    }
    fourth_arg_ptr = &fourth_arg;
    va_end(ap);

    return (semsys(0, semid, semnum, cmd, fourth_arg_ptr));
}
-end----------------

tim