src/nice.c

   1 /* nice -- run a program with modified scheduling priority
   2    Copyright (C) 1990-1999 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 "error.h"
  34 #include "long-options.h"
  35 #include "xstrtol.h"
  36
  37 /* The official name of this program (e.g., no `g' prefix).  */
  38 #define PROGRAM_NAME "nice"
  39
  40 #define AUTHORS "David MacKenzie"
  41
  42 #ifdef NICE_PRIORITY
  43 # define GET_PRIORITY() nice (0)
  44 #else
  45 # define GET_PRIORITY() getpriority (PRIO_PROCESS, 0)
  46 #endif
  47
  48 /* The name this program was run with. */
  49 char *program_name;
  50
  51 static struct option const longopts[] =
  52 {
  53   {"adjustment", required_argument, NULL, 'n'},
  54   {NULL, 0, NULL, 0}
  55 };
  56
  57 void
  58 usage (int status)
  59 {
  60   if (status != 0)
  61     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  62              program_name);
  63   else
  64     {
  65       printf (_("Usage: %s [OPTION] [COMMAND [ARG]...]\n"), program_name);
  66       printf (_("\
  67 Run COMMAND with an adjusted scheduling priority.\n\
  68 With no COMMAND, print the current scheduling priority.  ADJUST is 10\n\
  69 by default.  Range goes from -20 (highest priority) to 19 (lowest).\n\
  70 \n\
  71   -ADJUST                   increment priority by ADJUST first\n\
  72   -n, --adjustment=ADJUST   same as -ADJUST\n\
  73       --help                display this help and exit\n\
  74       --version             output version information and exit\n"));
  75       puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
  76     }
  77   exit (status);
  78 }
  79
  80 int
  81 main (int argc, char **argv)
  82 {
  83   int current_priority;
  84   long int adjustment = 0;
  85   int minusflag = 0;
  86   int adjustment_given = 0;
  87   int i;
  88
  89   program_name = argv[0];
  90   setlocale (LC_ALL, "");
  91   bindtextdomain (PACKAGE, LOCALEDIR);
  92   textdomain (PACKAGE);
  93
  94   parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
  95                       AUTHORS, usage);
  96
  97   for (i = 1; i < argc; /* empty */)
  98     {
  99       char *s = argv[i];
 100
 101       if (s[0] == '-' && s[1] == '-' && ISDIGIT (s[2]))
 102         {
 103           if (xstrtol (&s[2], NULL, 10, &adjustment, "") != LONGINT_OK)
 104             error (1, 0, _("invalid option `%s'"), s);
 105
 106           minusflag = 1;
 107           adjustment_given = 1;
 108           ++i;
 109         }
 110       else if (s[0] == '-' && (ISDIGIT (s[1])
 111                                || (s[1] == '+' && ISDIGIT (s[2]))))
 112         {
 113           if (s[1] == '+')
 114             ++s;
 115           if (xstrtol (&s[1], NULL, 10, &adjustment, "") != LONGINT_OK)
 116             error (1, 0, _("invalid option `%s'"), s);
 117
 118           minusflag = 0;
 119           adjustment_given = 1;
 120           ++i;
 121         }
 122       else
 123         {
 124           int optc;
 125           char **fake_argv = argv + i - 1;
 126
 127           /* Initialize getopt_long's internal state.  */
 128           optind = 0;
 129
 130           if ((optc = getopt_long (argc - (i - 1), fake_argv, "+n:",
 131                                    longopts, NULL)) != -1)
 132             {
 133               switch (optc)
 134                 {
 135                 case '?':
 136                   usage (1);
 137
 138                 case 'n':
 139                   if (xstrtol (optarg, NULL, 10, &adjustment, "")
 140                       != LONGINT_OK)
 141                     error (1, 0, _("invalid priority `%s'"), optarg);
 142
 143                   minusflag = 0;
 144                   adjustment_given = 1;
 145                   break;
 146                 }
 147             }
 148
 149           i += optind - 1;
 150
 151           if (optc == EOF)
 152             break;
 153         }
 154     }
 155
 156   if (minusflag)
 157     adjustment = -adjustment;
 158   if (!adjustment_given)
 159     adjustment = 10;
 160
 161   if (i == argc)
 162     {
 163       if (adjustment_given)
 164         {
 165           error (0, 0, _("a command must be given with an adjustment"));
 166           usage (1);
 167         }
 168       /* No command given; print the priority. */
 169       errno = 0;
 170       current_priority = GET_PRIORITY ();
 171       if (current_priority == -1 && errno != 0)
 172         error (1, errno, _("cannot get priority"));
 173       printf ("%d\n", current_priority);
 174       exit (0);
 175     }
 176
 177 #ifndef NICE_PRIORITY
 178   errno = 0;
 179   current_priority = GET_PRIORITY ();
 180   if (current_priority == -1 && errno != 0)
 181     error (1, errno, _("cannot get priority"));
 182   if (setpriority (PRIO_PROCESS, 0, current_priority + adjustment))
 183 #else
 184   if (nice (adjustment) == -1)
 185 #endif
 186     error (1, errno, _("cannot set priority"));
 187
 188   execvp (argv[i], &argv[i]);
 189
 190   {
 191     int exit_status = (errno == ENOENT ? 127 : 126);
 192     error (0, errno, "%s", argv[i]);
 193     exit (exit_status);
 194   }
 195 }