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 "long-options.h"
  34 #include "error.h"
  35
  36 /* The official name of this program (e.g., no `g' prefix).  */
  37 #define PROGRAM_NAME "nice"
  38
  39 #define AUTHORS "David MacKenzie"
  40
  41 #ifdef NICE_PRIORITY
  42 # define GET_PRIORITY() nice (0)
  43 #else
  44 # define GET_PRIORITY() getpriority (PRIO_PROCESS, 0)
  45 #endif
  46
  47 static int isinteger PARAMS ((char *s));
  48
  49 /* The name this program was run with. */
  50 char *program_name;
  51
  52 static struct option const longopts[] =
  53 {
  54   {"adjustment", required_argument, NULL, 'n'},
  55   {NULL, 0, NULL, 0}
  56 };
  57
  58 void
  59 usage (int status)
  60 {
  61   if (status != 0)
  62     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  63              program_name);
  64   else
  65     {
  66       printf (_("Usage: %s [OPTION]... [COMMAND [ARG]...]\n"), program_name);
  67       printf (_("\
  68 Run COMMAND with an adjusted scheduling priority.\n\
  69 With no COMMAND, print the current scheduling priority.  ADJUST is 10\n\
  70 by default.  Range goes from -20 (highest priority) to 19 (lowest).\n\
  71 \n\
  72   -ADJUST                   increment priority by ADJUST first\n\
  73   -n, --adjustment=ADJUST   same as -ADJUST\n\
  74       --help                display this help and exit\n\
  75       --version             output version information and exit\n"));
  76       puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
  77     }
  78   exit (status);
  79 }
  80
  81 int
  82 main (int argc, char **argv)
  83 {
  84   int current_priority;
  85   int adjustment = 0;
  86   int minusflag = 0;
  87   int adjustment_given = 0;
  88   int i;
  89
  90   program_name = argv[0];
  91   setlocale (LC_ALL, "");
  92   bindtextdomain (PACKAGE, LOCALEDIR);
  93   textdomain (PACKAGE);
  94
  95   parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
  96                       AUTHORS, usage);
  97
  98   for (i = 1; i < argc; /* empty */)
  99     {
 100       char *s = argv[i];
 101
 102       if (s[0] == '-' && s[1] == '-' && ISDIGIT (s[2]))
 103         {
 104           if (!isinteger (&s[2]))
 105             error (1, 0, _("invalid option `%s'"), s);
 106
 107           minusflag = 1;
 108           /* FIXME: use xstrtol */
 109           adjustment = atoi (&s[2]);
 110           adjustment_given = 1;
 111           ++i;
 112         }
 113       else if (s[0] == '-' && (ISDIGIT (s[1])
 114                                || (s[1] == '+' && ISDIGIT (s[2]))))
 115         {
 116           if (s[1] == '+')
 117             ++s;
 118           if (!isinteger (&s[1]))
 119             error (1, 0, _("invalid option `%s'"), s);
 120
 121           minusflag = 0;
 122           /* FIXME: use xstrtol */
 123           adjustment = atoi (&s[1]);
 124           adjustment_given = 1;
 125           ++i;
 126         }
 127       else
 128         {
 129           int optc;
 130           char **fake_argv = argv + i - 1;
 131
 132           /* Initialize getopt_long's internal state.  */
 133           optind = 0;
 134
 135           if ((optc = getopt_long (argc - (i - 1), fake_argv, "+n:",
 136                                    longopts, NULL)) != -1)
 137             {
 138               switch (optc)
 139                 {
 140                 case '?':
 141                   usage (1);
 142
 143                 case 'n':
 144                   if (!isinteger (optarg))
 145                     error (1, 0, _("invalid priority `%s'"), optarg);
 146
 147                   minusflag = 0;
 148                   /* FIXME: use xstrtol */
 149                   adjustment = atoi (optarg);
 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   error (errno == ENOENT ? 127 : 126, errno, "%s", argv[i]);
 196 }
 197
 198 /* Return nonzero if S represents a (possibly signed) decimal integer,
 199    zero if not. */
 200
 201 static int
 202 isinteger (char *s)
 203 {
 204   if (*s == '-' || *s == '+')
 205     ++s;
 206   if (*s == 0)
 207     return 0;
 208   while (*s)
 209     {
 210       if (!ISDIGIT (*s))
 211         return 0;
 212       ++s;
 213     }
 214   return 1;
 215 }