package main

import (
	"bufio"
	"fmt"
	"golang.org/x/term"
	"os"
)

func isAscii(char rune) bool {
	ord := int(char)

	return ord < 0x80
}

func isCtrl(char rune) bool {
	if ! isAscii(char) {
		return false
	}

	ord:= int(char)

	return ord == 0x7f || ord < 0x20
}

func goRaw() (*term.State, error) {
	state, err := term.MakeRaw(int(os.Stdin.Fd()))

	return state, err
}

func main() {
	// Go to proper raw mode
	oldState, err := goRaw()
	if err != nil {
		panic(err)
	}

	// Restore canonical mode at exit
	defer term.Restore(int(os.Stdin.Fd()), oldState)

	reader := bufio.NewReader(os.Stdin)

	for {
		char, _, err := reader.ReadRune()
		if err != nil {
			panic(err)
		}

		switch {
		case char == 'q':
			fmt.Println("bye!\r")
			return
		case isCtrl(char):
			fmt.Printf("%d\n", char)
		default:
			fmt.Printf("%d ('%c')\n", char, char)
		}

		_ = os.Stdout.Sync()
	}
}