nice.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 1986 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/* from UCB 4.1 83/05/30 */
#include <sys/time.h>
#include <sys/resource.h>
#include <errno.h>
/*
* Backwards compatible nice.
*/
int
nice(incr)
int incr;
{
register int prio;
int serrno;
/* put in brain-damaged upper range checking */
if ((incr > 40) && (geteuid() != 0)) {
errno = EPERM;
return (-1);
}
serrno = errno;
errno = 0;
prio = getpriority(PRIO_PROCESS, 0);
if (prio == -1 && errno)
return (-1);
prio += incr;
if (prio < -20)
prio = -20;
else if (prio > 19)
prio = 19;
if (setpriority(PRIO_PROCESS, 0, prio) == -1) {
/*
* 4.3BSD stupidly returns EACCES on an attempt by a
* non-super-user process to lower a priority; map
* it to EPERM.
*/
if (errno == EACCES)
errno = EPERM;
return (-1);
}
errno = serrno;
return (prio);
}