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From:	=?iso-8859-1?Q?Mikael_=C5sberg?= <mikas493 AT student DOT liu DOT se>
To:	<cygwin AT cygwin DOT com>
Subject:	Where did the output go and question regarding return values of getopt_long()
Date:	Sun, 19 Dec 2004 16:14:53 +0100
MIME-Version:	1.0

Hello, consider this c++-function:

void
handle_command_line(int argc,
                    char* const argv[],
                    bool& verbose,
                    vector<string>& numbers)
{
   const int id_numbers = 4711;
   const int id_verbose = 4712;
   const int id_help = 4713;

   const option long_options[] =
   {
      {"numbers", 1, NULL, id_numbers},
      {"verbose", 0, NULL, id_verbose},
      {"help", 0, NULL, id_help},
      {NULL, 0, NULL, 0}
   };

   const char* const short_options = "";

   int c = 0;

   while((c = getopt_long(
             argc,
             argv,
             short_options,
             long_options,
             NULL)) != -1)
   {
      switch(c)
      {
         cout << "c = " << c << endl; /* Never shown on screen... */

         case id_numbers:
         {
            cout << "Calling extract_numbers() with " << optarg << endl;

            extract_numbers(optarg, numbers);

            break;
         }
         case id_verbose:
         {
            cout << "Setting verbose = true" << endl;

            verbose = true;

            break;
         }
         case id_help:
         {
            cout << "TODO: Add short description regarding usage here." << 
endl;

            exit(EXIT_SUCCESS);
         }
         /* c seems to equal '?' for missing parameter as well... */
         case ':':
         {
            cerr << "Missing parameter." << endl;

            break;
         }
         /* Only triggers for unknown options beginning with -- */
         case '?':
         {
            cerr << "Ignoring unknown option." << endl;

            break;
         }
         default:
         {
            /* Throw exception? */
            cerr << "Should not be reached." << endl;
         }
      }
   }
}

My first question is about the
cout << "c = " << c << endl;
inside the switch. I never see this output, why? I tried writing the output 
to a file as well but that file was empty when the program finished. All 
other "output-statements" are displayed just fine in this function (and the 
rest of the program).

And my second questions is why does getopt_long() return '?' for the error 
when an option requires an argument but none was supplied? I thought that it 
would return ? for unknown option and return : for missing required 
parameters, but it seems to return ? for both those errors (but it ouputs 
the correct diagnostic).

I'm using latest offical cygwin, all relevant packages up-to-date. Running 
fully-updated winxp pro.

Thanks for any replies 



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