manual/examples/longopt.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <getopt.h>
   4
   5 /* Flag set by @samp{--verbose}.  */
   6 static int verbose_flag;
   7
   8 int
   9 main (argc, argv)
  10      int argc;
  11      char **argv;
  12 {
  13   int c;
  14
  15   while (1)
  16     {
  17       static struct option long_options[] =
  18         {
  19           /* These options set a flag.  */
  20           {"verbose", 0, &verbose_flag, 1},
  21           {"brief", 0, &verbose_flag, 0},
  22           /* These options don't set a flag.
  23              We distinguish them by their indices.  */
  24           {"add", 1, 0, 0},
  25           {"append", 0, 0, 0},
  26           {"delete", 1, 0, 0},
  27           {"create", 0, 0, 0},
  28           {"file", 1, 0, 0},
  29           {0, 0, 0, 0}
  30         };
  31       /* @code{getopt_long} stores the option index here.  */
  32       int option_index = 0;
  33
  34       c = getopt_long (argc, argv, "abc:d:",
  35                        long_options, &option_index);
  36
  37       /* Detect the end of the options.  */
  38       if (c == -1)
  39         break;
  40
  41       switch (c)
  42         {
  43         case 0:
  44           /* If this option set a flag, do nothing else now.  */
  45           if (long_options[option_index].flag != 0)
  46             break;
  47           printf ("option %s", long_options[option_index].name);
  48           if (optarg)
  49             printf (" with arg %s", optarg);
  50           printf ("\n");
  51           break;
  52
  53         case 'a':
  54           puts ("option -a\n");
  55           break;
  56
  57         case 'b':
  58           puts ("option -b\n");
  59           break;
  60
  61         case 'c':
  62           printf ("option -c with value `%s'\n", optarg);
  63           break;
  64
  65         case 'd':
  66           printf ("option -d with value `%s'\n", optarg);
  67           break;
  68
  69         case '?':
  70           /* @code{getopt_long} already printed an error message.  */
  71           break;
  72
  73         default:
  74           abort ();
  75         }
  76     }
  77
  78   /* Instead of reporting @samp{--verbose}
  79      and @samp{--brief} as they are encountered,
  80      we report the final status resulting from them.  */
  81   if (verbose_flag)
  82     puts ("verbose flag is set");
  83
  84   /* Print any remaining command line arguments (not options).  */
  85   if (optind < argc)
  86     {
  87       printf ("non-option ARGV-elements: ");
  88       while (optind < argc)
  89         printf ("%s ", argv[optind++]);
  90       putchar ('\n');
  91     }
  92
  93   exit (0);
  94 }