renice.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 126 行

#ifndef lint
static	char	*sccsid = "@(#)renice.c	4.1	(ULTRIX)	7/2/90";
#endif

/************************************************************************
 *									*
 *			Copyright (c) 1988 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/
/*
 * Revision History
 *
 * 05-DEC-1988	JAW	If PID to renice is "0" then the processes that
 *			is reniced is the current running process.  This
 *			is a feature of the get/setpriority system calls.
 *
 */
#include <sys/time.h>
#include <sys/resource.h>
#include <stdio.h>
#include <pwd.h>

/*
 * Change the priority (nice) of processes
 * or groups of processes which are already
 * running.
 */
main(argc, argv)
	char **argv;
{
	int which = PRIO_PROCESS;
	int who = 0, prio, errs = 0;

	argc--, argv++;
	if (argc < 2) {
		fprintf(stderr, "usage: renice priority [ [ -p ] pids ] ");
		fprintf(stderr, "[ [ -g ] pgrps ] [ [ -u ] users ]\n");
		exit(1);
	}
	prio = atoi(*argv);
	argc--, argv++;
	if (prio > PRIO_MAX)
		prio = PRIO_MAX;
	if (prio < PRIO_MIN)
		prio = PRIO_MIN;
	for (; argc > 0; argc--, argv++) {
		if (strcmp(*argv, "-g") == 0) {
			which = PRIO_PGRP;
			continue;
		}
		if (strcmp(*argv, "-u") == 0) {
			which = PRIO_USER;
			continue;
		}
		if (strcmp(*argv, "-p") == 0) {
			which = PRIO_PROCESS;
			continue;
		}
		if (which == PRIO_USER) {
			register struct passwd *pwd = getpwnam(*argv);
			
			if (pwd == NULL) {
				fprintf(stderr, "renice: %s: unknown user\n",
					*argv);
				continue;
			}
			who = pwd->pw_uid;
		} else {
			who = atoi(*argv);
			if (who < 0) {
				fprintf(stderr, "renice: %s: bad value\n",
					*argv);
				continue;
			}
		}
		if (who == 0)	
			errs += donice(which, getpid(), prio);
		else
			errs += donice(which, who, prio);
	}
	exit(errs != 0);
}

donice(which, who, prio)
	int which, who, prio;
{
	int oldprio;
	extern int errno;

	errno = 0, oldprio = getpriority(which, who);
	if (oldprio == -1 && errno) {
		fprintf(stderr, "renice: %d: ", who);
		perror("getpriority");
		return (1);
	}
	if (setpriority(which, who, prio) < 0) {
		fprintf(stderr, "renice: %d: ", who);
		perror("setpriority");
		return (1);
	}
	printf("%d: old priority %d, new priority %d\n", who, oldprio, prio);
	return (0);
}