/* Copyright_License {

  XCSoar Glide Computer - http://www.xcsoar.org/
  Copyright (C) 2000-2015 The XCSoar Project
  A detailed list of copyright holders can be found in the file "AUTHORS".

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License
  as published by the Free Software Foundation; either version 2
  of the License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
}
*/

/*
 * Reads input from stdin, calculates the NMEA checksum, and prints
 * the lines with a correct checksum to stdout.
 *
 */

#include "NMEA/Checksum.hpp"

#include <stdio.h>
#include <string.h>

int
main(int argc, char **argv)
{
  char buffer[1024];

  const char *start = buffer;
  while ((start = fgets(buffer, sizeof(buffer) - 3, stdin)) != NULL) {
    const char *end = strchr(start, '*');
    if (end == NULL) {
      end = start + strlen(start);
      while (end > start && (end[-1] == '\n' || end[-1] == '\r'))
        --end;
    }

    printf("%.*s*%02x\n", (int)(end - buffer), buffer,
           NMEAChecksum(start, end - start));
  }

  return 0;
}
