src/nice.c

   1 /* nice -- run a program with modified scheduling priority
   2    Copyright (C) 90, 91, 92, 93, 94, 95, 1996 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 __P ((char *s));
  44 static void usage __P ((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
  63   program_name = argv[0];
  64   setlocale (LC_ALL, "");
  65   bindtextdomain (PACKAGE, LOCALEDIR);
  66   textdomain (PACKAGE);
  67
  68   parse_long_options (argc, argv, "nice", PACKAGE_VERSION, usage);
  69
  70   for (optind = 1; optind < argc; /* empty */)
  71     {
  72       char *s;
  73
  74       s = argv[optind];
  75
  76       if (s[0] == '-' && s[1] == '-' && ISDIGIT (s[2]))
  77         {
  78           if (!isinteger (&s[2]))
  79             error (1, 0, _("invalid option `%s'"), s);
  80
  81           minusflag = 1;
  82           /* FIXME: use xstrtol */
  83           adjustment = atoi (&s[2]);
  84           adjustment_given = 1;
  85           ++optind;
  86         }
  87       else if (s[0] == '-' && ISDIGIT (s[1]))
  88         {
  89           if (!isinteger (&s[1]))
  90             error (1, 0, _("invalid option `%s'"), s);
  91           /* FIXME: use xstrtol */
  92           adjustment = atoi (&s[1]);
  93           adjustment_given = 1;
  94           ++optind;
  95         }
  96       else
  97         {
  98           int optc;
  99           if ((optc = getopt_long (argc, argv, "+n:",
 100                                    longopts, (int *) 0)) != EOF)
 101             {
 102               switch (optc)
 103                 {
 104                 case '?':
 105                   usage (1);
 106
 107                 case 'n':
 108                   if (!isinteger (optarg))
 109                     error (1, 0, _("invalid priority `%s'"), optarg);
 110                   /* FIXME: use xstrtol */
 111                   adjustment = atoi (optarg);
 112                   adjustment_given = 1;
 113                   break;
 114                 }
 115             }
 116
 117           if (optc == EOF)
 118             break;
 119         }
 120     }
 121
 122   if (minusflag)
 123     adjustment = -adjustment;
 124   if (!adjustment_given)
 125     adjustment = 10;
 126
 127   if (optind == argc)
 128     {
 129       if (adjustment_given)
 130         {
 131           error (0, 0, _("a command must be given with an adjustment"));
 132           usage (1);
 133         }
 134       /* No command given; print the priority. */
 135       errno = 0;
 136       current_priority = GET_PRIORITY ();
 137       if (current_priority == -1 && errno != 0)
 138         error (1, errno, _("cannot get priority"));
 139       printf ("%d\n", current_priority);
 140       exit (0);
 141     }
 142
 143 #ifndef NICE_PRIORITY
 144   errno = 0;
 145   current_priority = GET_PRIORITY ();
 146   if (current_priority == -1 && errno != 0)
 147     error (1, errno, _("cannot get priority"));
 148   if (setpriority (PRIO_PROCESS, 0, current_priority + adjustment))
 149 #else
 150   if (nice (adjustment) == -1)
 151 #endif
 152     error (1, errno, _("cannot set priority"));
 153
 154   execvp (argv[optind], &argv[optind]);
 155   error (errno == ENOENT ? 127 : 126, errno, "%s", argv[optind]);
 156 }
 157
 158 /* Return nonzero if S represents a (possibly signed) decimal integer,
 159    zero if not. */
 160
 161 static int
 162 isinteger (char *s)
 163 {
 164   if (*s == '-' || *s == '+')
 165     ++s;
 166   if (*s == 0)
 167     return 0;
 168   while (*s)
 169     {
 170       if (!ISDIGIT (*s))
 171         return 0;
 172       ++s;
 173     }
 174   return 1;
 175 }
 176
 177 static void
 178 usage (int status)
 179 {
 180   if (status != 0)
 181     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 182              program_name);
 183   else
 184     {
 185       printf (_("Usage: %s [OPTION]... [COMMAND [ARG]...]\n"), program_name);
 186       printf (_("\
 187 Run COMMAND with an adjusted scheduling priority.\n\
 188 With no COMMAND, print the current scheduling priority.  ADJUST is 10\n\
 189 by default.  Range goes from -20 (highest priority) to 19 (lowest).\n\
 190 \n\
 191   -ADJUST                   increment priority by ADJUST first\n\
 192   -n, --adjustment=ADJUST   same as -ADJUST\n\
 193       --help                display this help and exit\n\
 194       --version             output version information and exit\n"));
 195     }
 196   exit (status);
 197 }