TDRP usage

The TDRP usage is printed out for the user if the command line option '-tdrp_usage' is invoked.

However, it is also conventional for the programmer to provide a complete usage for the program via the '-h' command line arg. In this case, the program should print out its specific usage, and then follow up with the TDRP usage.

The following code shows an example of a function which does this:

static void usage(char *prog_name, FILE *out)
{
  fprintf(out, "%s%s%s%s",
	  "Usage: ", prog_name, " [options as below]\n",
	  "   [ -h] produce this list.\n"
	  "   [ -debug ] print debug messages\n"
	  ..........);
  TDRP_usage(out);
}

The following code fragment demonstrates how it may be invoked:

  for (i =  1; i < argc; i++) {
    if (!strcmp(argv[i], "-h")) {
      usage(prog_name, stdout);
      exit(0);
    } else if .....

    }
  } /* i */