#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <termios.h>
#include <unistd.h>

/* defines */
#define CTRL_KEY(k) ((k) & 0x1f)

/* data */
struct termios orig_termios;

/* terminal */

void die(const char *s) {
  perror(s);
  exit(1);
}

void disableRawMode() {
  if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &orig_termios) == -1) {
    die("tcsetattr");
  }
}

void enableRawMode() {
  if (tcgetattr(STDIN_FILENO, &orig_termios) == -1) {
    die("tcgetattr");
  }
  atexit(disableRawMode);

  struct termios raw = orig_termios;
  raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
  raw.c_oflag &= ~(OPOST);
  raw.c_cflag |= (CS8);
  raw.c_lflag &= ~(ECHO | ICANON | ISIG | IEXTEN);
  raw.c_cc[VMIN] = 0;
  raw.c_cc[VTIME] = 1;

  if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) == -1) {
    die("tcgetattr");
  }
}

/* init */

int main() {
  char c;

  enableRawMode();

  while (1) {
    c = '\0';
    if (read(STDIN_FILENO, &c, 1) == -1 && errno != EAGAIN) {
      die("read");
    }
    if (iscntrl(c)) {
      printf("%d\r\n", c);
    } else {
      printf("%d ('%c')\r\n", c, c);
    }
    if (c == CTRL_KEY('q')) {
      break;
    }
  }
  return 0;
}