manual/examples/longopt.c

   1 #include <stdio.h>
   2
   3 /* Flag set by @samp{--verbose}.  */
   4 static int verbose_flag;
   5
   6 int
   7 main (argc, argv)
   8      int argc;
   9      char **argv;
  10 {
  11   int c;
  12
  13   while (1)
  14     {
  15       static struct option long_options[] =
  16         {
  17           /* These options set a flag.  */
  18           {"verbose", 0, &verbose_flag, 1},
  19           {"brief", 0, &verbose_flag, 0},
  20           /* These options don't set a flag.
  21              We distinguish them by their indices.  */
  22           {"add", 1, 0, 0},
  23           {"append", 0, 0, 0},
  24           {"delete", 1, 0, 0},
  25           {"create", 0, 0, 0},
  26           {"file", 1, 0, 0},
  27           {0, 0, 0, 0}
  28         };
  29       /* @code{getopt_long} stores the option index here.  */
  30       int option_index = 0;
  31
  32       c = getopt_long (argc, argv, "abc:d:",
  33                        long_options, &option_index);
  34
  35       /* Detect the end of the options.  */
  36       if (c == -1)
  37         break;
  38
  39       switch (c)
  40         {
  41         case 0:
  42           /* If this option set a flag, do nothing else now.  */
  43           if (long_options[option_index].flag != 0)
  44             break;
  45           printf ("option %s", long_options[option_index].name);
  46           if (optarg)
  47             printf (" with arg %s", optarg);
  48           printf ("\n");
  49           break;
  50
  51         case 'a':
  52           puts ("option -a\n");
  53           break;
  54
  55         case 'b':
  56           puts ("option -b\n");
  57           break;
  58
  59         case 'c':
  60           printf ("option -c with value `%s'\n", optarg);
  61           break;
  62
  63         case 'd':
  64           printf ("option -d with value `%s'\n", optarg);
  65           break;
  66
  67         case '?':
  68           /* @code{getopt_long} already printed an error message.  */
  69           break;
  70
  71         default:
  72           abort ();
  73         }
  74     }
  75
  76   /* Instead of reporting @samp{--verbose}
  77      and @samp{--brief} as they are encountered,
  78      we report the final status resulting from them.  */
  79   if (verbose_flag)
  80     puts ("verbose flag is set");
  81
  82   /* Print any remaining command line arguments (not options).  */
  83   if (optind < argc)
  84     {
  85       printf ("non-option ARGV-elements: ");
  86       while (optind < argc)
  87         printf ("%s ", argv[optind++]);
  88       putchar ('\n');
  89     }
  90
  91   exit (0);
  92 }