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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#) Copyright (c) 1989, 1993, 1994 The Regents of the University of California.  All rights reserved.
  34  * @(#)nice.c   8.2 (Berkeley) 4/16/94
  35  * $FreeBSD: src/usr.bin/nice/nice.c,v 1.4.2.1 2002/06/18 08:40:28 tjr Exp $
  36  * $DragonFly: src/usr.bin/nice/nice.c,v 1.6 2005/10/09 15:09:02 liamfoy Exp $
  37  */
  38
  39 #include <sys/time.h>
  40 #include <sys/resource.h>
  41
  42 #include <ctype.h>
  43 #include <err.h>
  44 #include <errno.h>
  45 #include <limits.h>
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <unistd.h>
  50
  51 #define DEFNICE 10
  52
  53 static void     usage(void);
  54
  55 int
  56 main(int argc, char **argv)
  57 {
  58         long niceness = DEFNICE;
  59         int ch;
  60         char *ep;
  61
  62         /* Obsolescent syntax: -number, --number */
  63         if (argc >= 2 && argv[1][0] == '-' && (argv[1][1] == '-' ||
  64             isdigit(argv[1][1])) && strcmp(argv[1], "--") != 0)
  65                 if (asprintf(&argv[1], "-n%s", argv[1] + 1) < 0)
  66                         err(1, "asprintf");
  67
  68         while ((ch = getopt(argc, argv, "n:")) != -1) {
  69                 switch (ch) {
  70                 case 'n':
  71                         errno = 0;
  72                         niceness = strtol(optarg, &ep, 10);
  73                         if (ep == optarg || *ep != '\0' || errno ||
  74                             niceness < INT_MIN || niceness > INT_MAX)
  75                                 errx(1, "%s: invalid nice value", optarg);
  76                         break;
  77                 default:
  78                         usage();
  79                 }
  80         }
  81         argc -= optind;
  82         argv += optind;
  83
  84         if (argc == 0)
  85                 usage();
  86
  87         errno = 0;
  88         niceness += getpriority(PRIO_PROCESS, 0);
  89         if (errno)
  90                 warn("getpriority");
  91         else if (setpriority(PRIO_PROCESS, 0, (int)niceness))
  92                 warn("setpriority");
  93         execvp(*argv, argv);
  94         err(errno == ENOENT || errno == ENOTDIR ? 127 : 126, "%s", *argv);
  95 }
  96
  97 static void
  98 usage(void)
  99 {
 100
 101         fprintf(stderr, "usage: nice [-n incr] utility [arguments]\n");
 102         exit(1);
 103 }