1  /* Example of Parsing Long Options with getopt_long.
       2     Copyright (C) 1991-2023 Free Software Foundation, Inc.
       3  
       4     This program is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU General Public License
       6     as published by the Free Software Foundation; either version 2
       7     of the License, or (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  
      18  #include <stdio.h>
      19  #include <stdlib.h>
      20  #include <getopt.h>
      21  
      22  /* Flag set by @samp{--verbose}.  */
      23  static int verbose_flag;
      24  
      25  int
      26  main (int argc, char **argv)
      27  {
      28    int c;
      29  
      30    while (1)
      31      {
      32        static struct option long_options[] =
      33  	{
      34  	  /* These options set a flag.  */
      35  	  {"verbose", no_argument,       &verbose_flag, 1},
      36  	  {"brief",   no_argument,       &verbose_flag, 0},
      37  	  /* These options don't set a flag.
      38  	     We distinguish them by their indices.  */
      39  	  {"add",     no_argument,       0, 'a'},
      40  	  {"append",  no_argument,       0, 'b'},
      41  	  {"delete",  required_argument, 0, 'd'},
      42  	  {"create",  required_argument, 0, 'c'},
      43  	  {"file",    required_argument, 0, 'f'},
      44  	  {0, 0, 0, 0}
      45  	};
      46        /* @code{getopt_long} stores the option index here.  */
      47        int option_index = 0;
      48  
      49        c = getopt_long (argc, argv, "abc:d:f:",
      50  		       long_options, &option_index);
      51  
      52        /* Detect the end of the options.  */
      53        if (c == -1)
      54  	break;
      55  
      56        switch (c)
      57  	{
      58  	case 0:
      59  	  /* If this option set a flag, do nothing else now.  */
      60  	  if (long_options[option_index].flag != 0)
      61  	    break;
      62  	  printf ("option %s", long_options[option_index].name);
      63  	  if (optarg)
      64  	    printf (" with arg %s", optarg);
      65  	  printf ("\n");
      66  	  break;
      67  
      68  	case 'a':
      69  	  puts ("option -a\n");
      70  	  break;
      71  
      72  	case 'b':
      73  	  puts ("option -b\n");
      74  	  break;
      75  
      76  	case 'c':
      77  	  printf ("option -c with value `%s'\n", optarg);
      78  	  break;
      79  
      80  	case 'd':
      81  	  printf ("option -d with value `%s'\n", optarg);
      82  	  break;
      83  
      84  	case 'f':
      85  	  printf ("option -f with value `%s'\n", optarg);
      86  	  break;
      87  
      88  	case '?':
      89  	  /* @code{getopt_long} already printed an error message.  */
      90  	  break;
      91  
      92  	default:
      93  	  abort ();
      94  	}
      95      }
      96  
      97    /* Instead of reporting @samp{--verbose}
      98       and @samp{--brief} as they are encountered,
      99       we report the final status resulting from them.  */
     100    if (verbose_flag)
     101      puts ("verbose flag is set");
     102  
     103    /* Print any remaining command line arguments (not options).  */
     104    if (optind < argc)
     105      {
     106        printf ("non-option ARGV-elements: ");
     107        while (optind < argc)
     108  	printf ("%s ", argv[optind++]);
     109        putchar ('\n');
     110      }
     111  
     112    exit (0);
     113  }