src/nice.c

   1 /* nice -- run a program with modified scheduling priority
   2    Copyright (C) 1990-2001 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 #include "closeout.h"
  37
  38 /* The official name of this program (e.g., no `g' prefix).  */
  39 #define PROGRAM_NAME "nice"
  40
  41 #define AUTHORS "David MacKenzie"
  42
  43 #ifdef NICE_PRIORITY
  44 # define GET_PRIORITY() nice (0)
  45 #else
  46 # define GET_PRIORITY() getpriority (PRIO_PROCESS, 0)
  47 #endif
  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       fputs (_("\
  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 "), stdout);
  75       fputs (HELP_OPTION_DESCRIPTION, stdout);
  76       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  77       puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
  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         {
 107           if (xstrtol (&s[2], NULL, 10, &adjustment, "") != LONGINT_OK)
 108             error (1, 0, _("invalid option `%s'"), s);
 109
 110           minusflag = 1;
 111           adjustment_given = 1;
 112           ++i;
 113         }
 114       else if (s[0] == '-' && (ISDIGIT (s[1])
 115                                || (s[1] == '+' && ISDIGIT (s[2]))))
 116         {
 117           if (s[1] == '+')
 118             ++s;
 119           if (xstrtol (&s[1], NULL, 10, &adjustment, "") != LONGINT_OK)
 120             error (1, 0, _("invalid option `%s'"), s);
 121
 122           minusflag = 0;
 123           adjustment_given = 1;
 124           ++i;
 125         }
 126       else
 127         {
 128           int optc;
 129           char **fake_argv = argv + i - 1;
 130
 131           /* Initialize getopt_long's internal state.  */
 132           optind = 0;
 133
 134           if ((optc = getopt_long (argc - (i - 1), fake_argv, "+n:",
 135                                    longopts, NULL)) != -1)
 136             {
 137               switch (optc)
 138                 {
 139                 case '?':
 140                   usage (1);
 141
 142                 case 'n':
 143                   if (xstrtol (optarg, NULL, 10, &adjustment, "")
 144                       != LONGINT_OK)
 145                     error (1, 0, _("invalid priority `%s'"), optarg);
 146
 147                   minusflag = 0;
 148                   adjustment_given = 1;
 149                   break;
 150                 }
 151             }
 152
 153           i += optind - 1;
 154
 155           if (optc == EOF)
 156             break;
 157         }
 158     }
 159
 160   if (minusflag)
 161     adjustment = -adjustment;
 162   if (!adjustment_given)
 163     adjustment = 10;
 164
 165   if (i == argc)
 166     {
 167       if (adjustment_given)
 168         {
 169           error (0, 0, _("a command must be given with an adjustment"));
 170           usage (1);
 171         }
 172       /* No command given; print the priority. */
 173       errno = 0;
 174       current_priority = GET_PRIORITY ();
 175       if (current_priority == -1 && errno != 0)
 176         error (1, errno, _("cannot get priority"));
 177       printf ("%d\n", current_priority);
 178       exit (0);
 179     }
 180
 181 #ifndef NICE_PRIORITY
 182   errno = 0;
 183   current_priority = GET_PRIORITY ();
 184   if (current_priority == -1 && errno != 0)
 185     error (1, errno, _("cannot get priority"));
 186   if (setpriority (PRIO_PROCESS, 0, current_priority + adjustment))
 187 #else
 188   if (nice (adjustment) == -1)
 189 #endif
 190     error (1, errno, _("cannot set priority"));
 191
 192   execvp (argv[i], &argv[i]);
 193
 194   {
 195     int exit_status = (errno == ENOENT ? 127 : 126);
 196     error (0, errno, "%s", argv[i]);
 197     exit (exit_status);
 198   }
 199 }