/*
 * |-----------------------------------------------------------|
 * | Copyright (c) 1991, 1990 MIPS Computer Systems, Inc.      |
 * | All Rights Reserved                                       |
 * |-----------------------------------------------------------|
 * |          Restricted Rights Legend                         |
 * | Use, duplication, or disclosure by the Government is      |
 * | subject to restrictions as set forth in                   |
 * | subparagraph (c)(1)(ii) of the Rights in Technical        |
 * | Data and Computer Software Clause of DFARS 252.227-7013.  |
 * |         MIPS Computer Systems, Inc.                       |
 * |         950 DeGuigne Avenue                               |
 * |         Sunnyvale, California 94088-3650, USA             |
 * |-----------------------------------------------------------|
 */
#ident	"$Header: lockf.c,v 1.8.2.1 92/06/24 14:03:12 marker Exp $"

/*	Copyright (c) 1984 AT&T	*/
/*	  All Rights Reserved  	*/

/*	THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T	*/
/*	The copyright notice above does not evidence any   	*/
/*	actual or intended publication of such source code.	*/

#include <errno.h>
#include <fcntl.h>
#include <unistd.h>

lockf(fildes, function, size)
long size;
int fildes, function;
{
	struct flock l;
	int rv;

	l.l_whence = 1;
	if (size < 0) {
		l.l_start = size;
		l.l_len = -size;
	} else {
		l.l_start = 0L;
		l.l_len = size;
	}
	switch (function) {
	case F_ULOCK:
		l.l_type = F_UNLCK;
		rv = fcntl(fildes, F_SETLK, &l);
		break;
	case F_LOCK:
		l.l_type = F_WRLCK;
		rv = fcntl(fildes, F_SETLKW, &l);
		break;
	case F_TLOCK:
		l.l_type = F_WRLCK;
		rv = fcntl(fildes, F_SETLK, &l);
		break;
	case F_TEST:
		l.l_type = F_WRLCK;
		rv = fcntl(fildes, F_GETLK, &l);
		if (rv != -1) {
			if (l.l_type == F_UNLCK)
				return (0);
			else {
				errno = EACCES;
				return (-1);
			}
		}
		break;
	default:
		errno = EINVAL;
		return (-1);
	}
	if (rv < 0) {
		switch(errno) {
		case EMFILE:
		case ENOSPC:
		case ENOLCK:
			/* A deadlock error is given if we run out of resources,
			 * in compliance with /usr/group standards.
			 */
			errno = EDEADLK;
			break;
		default:
			break;
		}
	}
	return (rv);
}
