text: #pragma once
  
  #include <stdio.h>
  #include <termios.h>
  #include <unistd.h>
  #include <fcntl.h>
  
  int kbhit(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;
  }
  