src/nice.c

   1 /* nice -- run a program with modified scheduling priority
   2    Copyright (C) 1990-2002 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* David MacKenzie <djm@gnu.ai.mit.edu> */
  19
  20 #include <config.h>
  21 #include <stdio.h>
  22
  23 #include <assert.h>
  24
  25 #include <getopt.h>
  26 #include <sys/types.h>
  27 #ifndef NICE_PRIORITY
  28 # include <sys/time.h>
  29 # include <sys/resource.h>
  30 #endif
  31
  32 #include "system.h"
  33 #include "closeout.h"
  34 #include "error.h"
  35 #include "long-options.h"
  36 #include "posixver.h"
  37 #include "xstrtol.h"
  38
  39 /* The official name of this program (e.g., no `g' prefix).  */
  40 #define PROGRAM_NAME "nice"
  41
  42 #define AUTHORS "David MacKenzie"
  43
  44 #ifdef NICE_PRIORITY
  45 # define GET_PRIORITY() nice (0)
  46 #else
  47 # define GET_PRIORITY() getpriority (PRIO_PROCESS, 0)
  48 #endif
  49
  50 /* The name this program was run with. */
  51 char *program_name;
  52
  53 static struct option const longopts[] =
  54 {
  55   {"adjustment", required_argument, NULL, 'n'},
  56   {NULL, 0, NULL, 0}
  57 };
  58
  59 void
  60 usage (int status)
  61 {
  62   if (status != 0)
  63     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  64              program_name);
  65   else
  66     {
  67       printf (_("Usage: %s [OPTION] [COMMAND [ARG]...]\n"), program_name);
  68       fputs (_("\
  69 Run COMMAND with an adjusted scheduling priority.\n\
  70 With no COMMAND, print the current scheduling priority.  ADJUST is 10\n\
  71 by default.  Range goes from -20 (highest priority) to 19 (lowest).\n\
  72 \n\
  73   -n, --adjustment=ADJUST   increment priority by ADJUST first\n\
  74 "), stdout);
  75       fputs (HELP_OPTION_DESCRIPTION, stdout);
  76       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  77       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
  78     }
  79   exit (status);
  80 }
  81
  82 int
  83 main (int argc, char **argv)
  84 {
  85   int current_priority;
  86   long int adjustment = 0;
  87   int minusflag = 0;
  88   int adjustment_given = 0;
  89   int i;
  90
  91   program_name = argv[0];
  92   setlocale (LC_ALL, "");
  93   bindtextdomain (PACKAGE, LOCALEDIR);
  94   textdomain (PACKAGE);
  95
  96   atexit (close_stdout);
  97
  98   parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
  99                       AUTHORS, usage);
 100
 101   for (i = 1; i < argc; /* empty */)
 102     {
 103       char *s = argv[i];
 104
 105       if (s[0] == '-' && s[1] == '-' && ISDIGIT (s[2])
 106           && posix2_version () < 200112)
 107         {
 108           if (xstrtol (&s[2], NULL, 10, &adjustment, "") != LONGINT_OK)
 109             error (1, 0, _("invalid option `%s'"), s);
 110
 111           minusflag = 1;
 112           adjustment_given = 1;
 113           ++i;
 114         }
 115       else if (s[0] == '-'
 116                && (ISDIGIT (s[1]) || (s[1] == '+' && ISDIGIT (s[2])))
 117                && posix2_version () < 200112)
 118         {
 119           if (s[1] == '+')
 120             ++s;
 121           if (xstrtol (&s[1], NULL, 10, &adjustment, "") != LONGINT_OK)
 122             error (1, 0, _("invalid option `%s'"), s);
 123
 124           minusflag = 0;
 125           adjustment_given = 1;
 126           ++i;
 127         }
 128       else
 129         {
 130           int optc;
 131           char **fake_argv = argv + i - 1;
 132
 133           /* Initialize getopt_long's internal state.  */
 134           optind = 0;
 135
 136           if ((optc = getopt_long (argc - (i - 1), fake_argv, "+n:",
 137                                    longopts, NULL)) != -1)
 138             {
 139               switch (optc)
 140                 {
 141                 case '?':
 142                   usage (1);
 143
 144                 case 'n':
 145                   if (xstrtol (optarg, NULL, 10, &adjustment, "")
 146                       != LONGINT_OK)
 147                     error (1, 0, _("invalid priority `%s'"), optarg);
 148
 149                   minusflag = 0;
 150                   adjustment_given = 1;
 151                   break;
 152                 }
 153             }
 154
 155           i += optind - 1;
 156
 157           if (optc == EOF)
 158             break;
 159         }
 160     }
 161
 162   if (minusflag)
 163     adjustment = -adjustment;
 164   if (!adjustment_given)
 165     adjustment = 10;
 166
 167   if (i == argc)
 168     {
 169       if (adjustment_given)
 170         {
 171           error (0, 0, _("a command must be given with an adjustment"));
 172           usage (1);
 173         }
 174       /* No command given; print the priority. */
 175       errno = 0;
 176       current_priority = GET_PRIORITY ();
 177       if (current_priority == -1 && errno != 0)
 178         error (1, errno, _("cannot get priority"));
 179       printf ("%d\n", current_priority);
 180       exit (0);
 181     }
 182
 183 #ifndef NICE_PRIORITY
 184   errno = 0;
 185   current_priority = GET_PRIORITY ();
 186   if (current_priority == -1 && errno != 0)
 187     error (1, errno, _("cannot get priority"));
 188   if (setpriority (PRIO_PROCESS, 0, current_priority + adjustment))
 189 #else
 190   if (nice (adjustment) == -1)
 191 #endif
 192     error (1, errno, _("cannot set priority"));
 193
 194   execvp (argv[i], &argv[i]);
 195
 196   {
 197     int exit_status = (errno == ENOENT ? 127 : 126);
 198     error (0, errno, "%s", argv[i]);
 199     exit (exit_status);
 200   }
 201 }