1  /* nproc - print the number of processors.
       2     Copyright (C) 2009-2023 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 3 of the License, or
       7     (at your option) 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, see <https://www.gnu.org/licenses/>.  */
      16  
      17  /* Written by Giuseppe Scrivano.  */
      18  
      19  #include <config.h>
      20  #include <getopt.h>
      21  #include <stdio.h>
      22  #include <sys/types.h>
      23  
      24  #include "system.h"
      25  #include "nproc.h"
      26  #include "quote.h"
      27  #include "xdectoint.h"
      28  
      29  /* The official name of this program (e.g., no 'g' prefix).  */
      30  #define PROGRAM_NAME "nproc"
      31  
      32  #define AUTHORS proper_name ("Giuseppe Scrivano")
      33  
      34  enum
      35  {
      36    ALL_OPTION = CHAR_MAX + 1,
      37    IGNORE_OPTION
      38  };
      39  
      40  static struct option const longopts[] =
      41  {
      42    {"all", no_argument, nullptr, ALL_OPTION},
      43    {"ignore", required_argument, nullptr, IGNORE_OPTION},
      44    {GETOPT_HELP_OPTION_DECL},
      45    {GETOPT_VERSION_OPTION_DECL},
      46    {nullptr, 0, nullptr, 0}
      47  };
      48  
      49  void
      50  usage (int status)
      51  {
      52    if (status != EXIT_SUCCESS)
      53      emit_try_help ();
      54    else
      55      {
      56        printf (_("Usage: %s [OPTION]...\n"), program_name);
      57        fputs (_("\
      58  Print the number of processing units available to the current process,\n\
      59  which may be less than the number of online processors\n\
      60  \n\
      61  "), stdout);
      62        fputs (_("\
      63        --all      print the number of installed processors\n\
      64        --ignore=N  if possible, exclude N processing units\n\
      65  "), stdout);
      66  
      67        fputs (HELP_OPTION_DESCRIPTION, stdout);
      68        fputs (VERSION_OPTION_DESCRIPTION, stdout);
      69        emit_ancillary_info (PROGRAM_NAME);
      70      }
      71    exit (status);
      72  }
      73  
      74  int
      75  main (int argc, char **argv)
      76  {
      77    unsigned long nproc, ignore = 0;
      78    initialize_main (&argc, &argv);
      79    set_program_name (argv[0]);
      80    setlocale (LC_ALL, "");
      81    bindtextdomain (PACKAGE, LOCALEDIR);
      82    textdomain (PACKAGE);
      83  
      84    atexit (close_stdout);
      85  
      86    enum nproc_query mode = NPROC_CURRENT_OVERRIDABLE;
      87  
      88    while (true)
      89      {
      90        int c = getopt_long (argc, argv, "", longopts, nullptr);
      91        if (c == -1)
      92          break;
      93        switch (c)
      94          {
      95          case_GETOPT_HELP_CHAR;
      96  
      97          case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
      98  
      99          case ALL_OPTION:
     100            mode = NPROC_ALL;
     101            break;
     102  
     103          case IGNORE_OPTION:
     104            ignore = xdectoumax (optarg, 0, ULONG_MAX, "", _("invalid number"),0);
     105            break;
     106  
     107          default:
     108            usage (EXIT_FAILURE);
     109          }
     110      }
     111  
     112    if (argc != optind)
     113      {
     114        error (0, 0, _("extra operand %s"), quote (argv[optind]));
     115        usage (EXIT_FAILURE);
     116      }
     117  
     118    nproc = num_processors (mode);
     119  
     120    if (ignore < nproc)
     121      nproc -= ignore;
     122    else
     123      nproc = 1;
     124  
     125    printf ("%lu\n", nproc);
     126  
     127    return EXIT_SUCCESS;
     128  }