src/nice.c

   1 /* nice -- run a program with modified scheduling priority
   2    Copyright (C) 90,91,92,93,94,95,96,1997 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 #define NDEBUG
  24 #include <assert.h>
  25
  26 #include <getopt.h>
  27 #include <sys/types.h>
  28 #ifndef NICE_PRIORITY
  29 # include <sys/time.h>
  30 # include <sys/resource.h>
  31 #endif
  32
  33 #include "system.h"
  34 #include "long-options.h"
  35 #include "error.h"
  36
  37 #ifdef NICE_PRIORITY
  38 # define GET_PRIORITY() nice (0)
  39 #else
  40 # define GET_PRIORITY() getpriority (PRIO_PROCESS, 0)
  41 #endif
  42
  43 static int isinteger PARAMS ((char *s));
  44 static void usage PARAMS ((int status));
  45
  46 /* The name this program was run with. */
  47 char *program_name;
  48
  49 static struct option const longopts[] =
  50 {
  51   {"adjustment", required_argument, NULL, 'n'},
  52   {NULL, 0, NULL, 0}
  53 };
  54
  55 int
  56 main (int argc, char **argv)
  57 {
  58   int current_priority;
  59   int adjustment = 0;
  60   int minusflag = 0;
  61   int adjustment_given = 0;
  62   int i;
  63
  64   program_name = argv[0];
  65   setlocale (LC_ALL, "");
  66   bindtextdomain (PACKAGE, LOCALEDIR);
  67   textdomain (PACKAGE);
  68
  69   parse_long_options (argc, argv, "nice", GNU_PACKAGE, VERSION, usage);
  70
  71   for (i = 1; i < argc; /* empty */)
  72     {
  73       char *s = argv[i];
  74
  75       if (s[0] == '-' && s[1] == '-' && ISDIGIT (s[2]))
  76         {
  77           if (!isinteger (&s[2]))
  78             error (1, 0, _("invalid option `%s'"), s);
  79
  80           minusflag = 1;
  81           /* FIXME: use xstrtol */
  82           adjustment = atoi (&s[2]);
  83           adjustment_given = 1;
  84           ++i;
  85         }
  86       else if (s[0] == '-' && (ISDIGIT (s[1])
  87                                || (s[1] == '+' && ISDIGIT (s[2]))))
  88         {
  89           if (s[1] == '+')
  90             ++s;
  91           if (!isinteger (&s[1]))
  92             error (1, 0, _("invalid option `%s'"), s);
  93
  94           minusflag = 0;
  95           /* FIXME: use xstrtol */
  96           adjustment = atoi (&s[1]);
  97           adjustment_given = 1;
  98           ++i;
  99         }
 100       else
 101         {
 102           int optc;
 103           char **fake_argv = argv + i - 1;
 104
 105           /* Initialize getopt_long's internal state.  */
 106           optind = 0;
 107
 108           if ((optc = getopt_long (argc - (i - 1), fake_argv, "+n:",
 109                                    longopts, NULL)) != -1)
 110             {
 111               switch (optc)
 112                 {
 113                 case '?':
 114                   usage (1);
 115
 116                 case 'n':
 117                   if (!isinteger (optarg))
 118                     error (1, 0, _("invalid priority `%s'"), optarg);
 119
 120                   minusflag = 0;
 121                   /* FIXME: use xstrtol */
 122                   adjustment = atoi (optarg);
 123                   adjustment_given = 1;
 124                   break;
 125                 }
 126             }
 127
 128           i += optind - 1;
 129
 130           if (optc == EOF)
 131             break;
 132         }
 133     }
 134
 135   if (minusflag)
 136     adjustment = -adjustment;
 137   if (!adjustment_given)
 138     adjustment = 10;
 139
 140   if (i == argc)
 141     {
 142       if (adjustment_given)
 143         {
 144           error (0, 0, _("a command must be given with an adjustment"));
 145           usage (1);
 146         }
 147       /* No command given; print the priority. */
 148       errno = 0;
 149       current_priority = GET_PRIORITY ();
 150       if (current_priority == -1 && errno != 0)
 151         error (1, errno, _("cannot get priority"));
 152       printf ("%d\n", current_priority);
 153       exit (0);
 154     }
 155
 156 #ifndef NICE_PRIORITY
 157   errno = 0;
 158   current_priority = GET_PRIORITY ();
 159   if (current_priority == -1 && errno != 0)
 160     error (1, errno, _("cannot get priority"));
 161   if (setpriority (PRIO_PROCESS, 0, current_priority + adjustment))
 162 #else
 163   if (nice (adjustment) == -1)
 164 #endif
 165     error (1, errno, _("cannot set priority"));
 166
 167   execvp (argv[i], &argv[i]);
 168   error (errno == ENOENT ? 127 : 126, errno, "%s", argv[i]);
 169 }
 170
 171 /* Return nonzero if S represents a (possibly signed) decimal integer,
 172    zero if not. */
 173
 174 static int
 175 isinteger (char *s)
 176 {
 177   if (*s == '-' || *s == '+')
 178     ++s;
 179   if (*s == 0)
 180     return 0;
 181   while (*s)
 182     {
 183       if (!ISDIGIT (*s))
 184         return 0;
 185       ++s;
 186     }
 187   return 1;
 188 }
 189
 190 static void
 191 usage (int status)
 192 {
 193   if (status != 0)
 194     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 195              program_name);
 196   else
 197     {
 198       printf (_("Usage: %s [OPTION]... [COMMAND [ARG]...]\n"), program_name);
 199       printf (_("\
 200 Run COMMAND with an adjusted scheduling priority.\n\
 201 With no COMMAND, print the current scheduling priority.  ADJUST is 10\n\
 202 by default.  Range goes from -20 (highest priority) to 19 (lowest).\n\
 203 \n\
 204   -ADJUST                   increment priority by ADJUST first\n\
 205   -n, --adjustment=ADJUST   same as -ADJUST\n\
 206       --help                display this help and exit\n\
 207       --version             output version information and exit\n"));
 208       puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
 209     }
 210   exit (status);
 211 }