longopt.c.texi

一个C源代码分析器

#include <stdio.h>

/* @r{Flag set by @samp{--verbose}.} */
static int verbose_flag;

int
main (argc, argv)
     int argc;
     char **argv;
@{
  int c;

  while (1)
    @{
      static struct option long_options[] =
        @{
          /* @r{These options set a flag.} */
          @{"verbose", 0, &verbose_flag, 1@},
          @{"brief", 0, &verbose_flag, 0@},
          /* @r{These options don't set a flag.
             We distinguish them by their indices.} */
          @{"add", 1, 0, 0@},
          @{"append", 0, 0, 0@},
          @{"delete", 1, 0, 0@},
          @{"create", 0, 0, 0@},
          @{"file", 1, 0, 0@},
          @{0, 0, 0, 0@}
        @};
      /* @r{@code{getopt_long} stores the option index here.} */
      int option_index = 0;

      c = getopt_long (argc, argv, "abc:d:",
                       long_options, &option_index);

      /* @r{Detect the end of the options.} */
      if (c == -1)
        break;

      switch (c)
        @{
        case 0:
          /* @r{If this option set a flag, do nothing else now.} */
          if (long_options[option_index].flag != 0)
            break;
          printf ("option %s", long_options[option_index].name);
          if (optarg)
            printf (" with arg %s", optarg);
          printf ("\n");
          break;

        case 'a':
          puts ("option -a\n");
          break;

        case 'b':
          puts ("option -b\n");
          break;

        case 'c':
          printf ("option -c with value `%s'\n", optarg);
          break;

        case 'd':
          printf ("option -d with value `%s'\n", optarg);
          break;

        case '?':
          /* @r{@code{getopt_long} already printed an error message.} */
          break;

        default:
          abort ();
        @}
    @}

  /* @r{Instead of reporting @samp{--verbose}
     and @samp{--brief} as they are encountered,
     we report the final status resulting from them.} */
  if (verbose_flag)
    puts ("verbose flag is set");

  /* @r{Print any remaining command line arguments (not options).} */
  if (optind < argc)
    @{
      printf ("non-option ARGV-elements: ");
      while (optind < argc)
        printf ("%s ", argv[optind++]);
      putchar ('\n');
    @}

  exit (0);
@}