move promts to new package

internal/prompt/prompt.go

@@ -0,0 +1,40 @@
+package prompt
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+
+	"golang.org/x/term"
+)
+
+// TODO: use charm stuff for this
+
+func YesNo(prompt string) bool {
+	return AskRune(prompt, "y/n") == 'y'
+}
+
+func AskRune(prompt, options string) byte {
+	// TODO: handle errors better
+	// switch stdin into 'raw' mode
+	oldState, err := term.MakeRaw(int(os.Stdin.Fd()))
+	if err != nil {
+		panic(err)
+	}
+	defer func() {
+		if err := term.Restore(int(os.Stdin.Fd()), oldState); err != nil {
+			panic(err)
+		}
+	}()
+
+	fmt.Printf("%s [%s]: ", prompt, options)
+
+	// read one byte from stdin
+	b := make([]byte, 1)
+	_, err = os.Stdin.Read(b)
+	if err != nil {
+		return 0
+	}
+
+	return bytes.ToLower(b)[0]
+}