// non-blocking kbhit for linux or just _kbhit() on windows

#ifdef _WINDOWS

#include <conio.h>
#include <stdio.h>

#else

#include <stdio.h>
#include <termios.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/select.h>

#endif

int kbhit_no_buf(void)
{
  struct termios oldt, newt;
  int ch;
  int oldf;

  tcgetattr(STDIN_FILENO, &oldt);
  newt = oldt;
  newt.c_lflag &= ~(ICANON | ECHO);
  tcsetattr(STDIN_FILENO, TCSANOW, &newt);
  oldf = fcntl(STDIN_FILENO, F_GETFL, 0);
  fcntl(STDIN_FILENO, F_SETFL, oldf | O_NONBLOCK);

  ch = getchar();

  tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
  fcntl(STDIN_FILENO, F_SETFL, oldf);

  if(ch != EOF)
  {
    ungetc(ch, stdin);
    return 1;
  }

  return 0;
}


int kbhit()
{
#ifdef _WINDOWS
    return _kbhit();
#else
    struct timeval tv = { 0L, 0L };
    fd_set fds;
    FD_ZERO(&fds);
    FD_SET(0, &fds);
    return select(1, &fds, NULL, NULL, &tv);
#endif
}