/*******************************************************************
*                                                                  *
*             This software is part of the ast package             *
*                Copyright (c) 1985-2004 AT&T Corp.                *
*        and it may only be used by you under license from         *
*                       AT&T Corp. ("AT&T")                        *
*         A copy of the Source Code Agreement is available         *
*                at the AT&T Internet web site URL                 *
*                                                                  *
*       http://www.research.att.com/sw/license/ast-open.html       *
*                                                                  *
*    If you have copied or used this software without agreeing     *
*        to the terms of the license you are infringing on         *
*           the license and copyright and are violating            *
*               AT&T's intellectual property rights.               *
*                                                                  *
*            Information and Software Systems Research             *
*                        AT&T Labs Research                        *
*                         Florham Park NJ                          *
*                                                                  *
*               Glenn Fowler <gsf@research.att.com>                *
*                David Korn <dgk@research.att.com>                 *
*                 Phong Vo <kpv@research.att.com>                  *
*                                                                  *
*******************************************************************/
#pragma prototyped

#include <ast.h>

#if _lib_setpgid

NoN(setpgid)

#else

#include <error.h>

#ifndef ENOSYS
#define ENOSYS		EINVAL
#endif

#if _lib_setpgrp2
#define setpgrp		setpgrp2
#else
#if _lib_BSDsetpgrp
#define _lib_setpgrp2	1
#define setpgrp		BSDsetpgrp
#else
#if _lib_wait3
#define	_lib_setpgrp2	1
#endif
#endif
#endif

#if _lib_setpgrp2
extern int		setpgrp(int, int);
#else
extern int		setpgrp(void);
#endif

/*
 * set process group id
 */

int
setpgid(pid_t pid, pid_t pgid)
{
#if _lib_setpgrp2
	return(setpgrp(pid, pgid));
#else
#if _lib_setpgrp
	int	caller = getpid();

	if ((pid == 0 || pid == caller) && (pgid == 0 || pgid == caller))
		return(setpgrp());
	errno = EINVAL;
#else
	errno = ENOSYS;
#endif
	return(-1);
#endif
}

#endif
