/*****************************************************************************\
*   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.            *
\*****************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <linux/joystick.h>

#define JOY_DEV "/dev/js0"

int main()
{
  int joy_fd, *axis=NULL, num_of_axis=0, num_of_buttons=0, x;
  char *button=NULL, name_of_joystick[80];
  struct js_event js;

  if( ( joy_fd = open( JOY_DEV , O_RDONLY)) == -1 )
  {
    printf( "Couldn't open joystick\n" );
    return -1;
  }

  ioctl( joy_fd, JSIOCGAXES, &num_of_axis );
  ioctl( joy_fd, JSIOCGBUTTONS, &num_of_buttons );
  ioctl( joy_fd, JSIOCGNAME(80), &name_of_joystick );

  axis = (int *) calloc( num_of_axis, sizeof( int ) );
  button = (char *) calloc( num_of_buttons, sizeof( char ) );

  printf("Joystick detected: %s\n\t%d axis\n\t%d buttons\n\n"
    , name_of_joystick
    , num_of_axis
    , num_of_buttons );

  fcntl( joy_fd, F_SETFL, O_NONBLOCK );  /* use non-blocking mode */

  while( 1 )  /* infinite loop */
  {

    /* read the joystick state */
    read(joy_fd, &js, sizeof(struct js_event));

    /* see what to do with the event */
    switch (js.type & ~JS_EVENT_INIT)
    {
      case JS_EVENT_AXIS:
        axis [ js.number ] = js.value;
        break;
      case JS_EVENT_BUTTON:
        button [ js.number ] = js.value;
        break;
    }

    /* print the results */
    printf( "X: %6d Y: %6d ", axis[0], axis[1] );

    if( num_of_axis > 2 )
      printf("Z: %6d ", axis[2] );

    if( num_of_axis > 3 )
      printf("R: %6d ", axis[3] );

    for( x=0 ; x < num_of_buttons ; ++x )
      printf("B%d: %d ", x, button[x] );

    printf(" \r");
    fflush(stdout);
  }

  close( joy_fd );
  return 0;
}