Question

I know how to use events to test when a key is pressed or not, but in C I never found out how to do that.

What I want exactly is a "KeyListener" that listens for the Up, Down, Left and Right arrow keys. I need it to work in Linux, so no Windows libraries. And, if possible, using no 3rd party libraries is the best option for me.

Pseudocode of what I want:

int main() {
 
    // key listener {
    // if(key == up) { // do something }
    // if(key == down) { // do something }
    // if(key == left) { // do something }
    // if(key == right) { // do something }
    // }
}

Answer 1

How about using SDL to read the keyboard too.

  SDL_Event event;
  .
  .
  /* Poll for events. SDL_PollEvent() returns 0 when there are no  */
  /* more events on the event queue, our while loop will exit when */
  /* that occurs.                                                  */
  while( SDL_PollEvent( &event ) ){
    /* We are only worried about SDL_KEYDOWN and SDL_KEYUP events */
    switch( event.type ){
      case SDL_KEYDOWN:
        printf( "Key press detected\n" );

        if (event.key.keysym.sym==SDLK_UP) 
            printf( "It was the UP key\n" );

        break;
      case SDL_KEYUP:
        printf( "Key release detected\n" );
        break;

      default:
        break;
    }
  }
  .
  .

Source: http://www.libsdl.org/docs/html/guideinputkeyboard.html