usr.bin/nice/nice.c

   1 /*
   2  * Copyright (c) 1989, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#) Copyright (c) 1989, 1993, 1994 The Regents of the University of California.  All rights reserved.
  30  * @(#)nice.c   8.2 (Berkeley) 4/16/94
  31  * $FreeBSD: src/usr.bin/nice/nice.c,v 1.4.2.1 2002/06/18 08:40:28 tjr Exp $
  32  * $DragonFly: src/usr.bin/nice/nice.c,v 1.6 2005/10/09 15:09:02 liamfoy Exp $
  33  */
  34
  35 #include <sys/time.h>
  36 #include <sys/resource.h>
  37
  38 #include <ctype.h>
  39 #include <err.h>
  40 #include <errno.h>
  41 #include <limits.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45 #include <unistd.h>
  46
  47 #define DEFNICE 10
  48
  49 static void     usage(void);
  50
  51 int
  52 main(int argc, char **argv)
  53 {
  54         long niceness = DEFNICE;
  55         int ch;
  56         char *ep;
  57
  58         /* Obsolescent syntax: -number, --number */
  59         if (argc >= 2 && argv[1][0] == '-' && (argv[1][1] == '-' ||
  60             isdigit(argv[1][1])) && strcmp(argv[1], "--") != 0)
  61                 if (asprintf(&argv[1], "-n%s", argv[1] + 1) < 0)
  62                         err(1, "asprintf");
  63
  64         while ((ch = getopt(argc, argv, "n:")) != -1) {
  65                 switch (ch) {
  66                 case 'n':
  67                         errno = 0;
  68                         niceness = strtol(optarg, &ep, 10);
  69                         if (ep == optarg || *ep != '\0' || errno ||
  70                             niceness < INT_MIN || niceness > INT_MAX)
  71                                 errx(1, "%s: invalid nice value", optarg);
  72                         break;
  73                 default:
  74                         usage();
  75                 }
  76         }
  77         argc -= optind;
  78         argv += optind;
  79
  80         if (argc == 0)
  81                 usage();
  82
  83         errno = 0;
  84         niceness += getpriority(PRIO_PROCESS, 0);
  85         if (errno)
  86                 warn("getpriority");
  87         else if (setpriority(PRIO_PROCESS, 0, (int)niceness))
  88                 warn("setpriority");
  89         execvp(*argv, argv);
  90         err(errno == ENOENT || errno == ENOTDIR ? 127 : 126, "%s", *argv);
  91 }
  92
  93 static void
  94 usage(void)
  95 {
  96
  97         fprintf(stderr, "usage: nice [-n incr] utility [arguments]\n");
  98         exit(1);
  99 }