chore: vendor

vendor/github.com/AlecAivazis/survey/v2/terminal/runereader_posix.go

@@ -0,0 +1,132 @@
+//go:build !windows
+// +build !windows
+
+// The terminal mode manipulation code is derived heavily from:
+// https://github.com/golang/crypto/blob/master/ssh/terminal/util.go:
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package terminal
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"syscall"
+	"unsafe"
+)
+
+const (
+	normalKeypad      = '['
+	applicationKeypad = 'O'
+)
+
+type runeReaderState struct {
+	term   syscall.Termios
+	reader *bufio.Reader
+	buf    *bytes.Buffer
+}
+
+func newRuneReaderState(input FileReader) runeReaderState {
+	buf := new(bytes.Buffer)
+	return runeReaderState{
+		reader: bufio.NewReader(&BufferedReader{
+			In:     input,
+			Buffer: buf,
+		}),
+		buf: buf,
+	}
+}
+
+func (rr *RuneReader) Buffer() *bytes.Buffer {
+	return rr.state.buf
+}
+
+// For reading runes we just want to disable echo.
+func (rr *RuneReader) SetTermMode() error {
+	if _, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(rr.stdio.In.Fd()), ioctlReadTermios, uintptr(unsafe.Pointer(&rr.state.term)), 0, 0, 0); err != 0 {
+		return err
+	}
+
+	newState := rr.state.term
+	newState.Lflag &^= syscall.ECHO | syscall.ECHONL | syscall.ICANON | syscall.ISIG
+	// Because we are clearing canonical mode, we need to ensure VMIN & VTIME are
+	// set to the values we expect. This combination puts things in standard
+	// "blocking read" mode (see termios(3)).
+	newState.Cc[syscall.VMIN] = 1
+	newState.Cc[syscall.VTIME] = 0
+
+	if _, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(rr.stdio.In.Fd()), ioctlWriteTermios, uintptr(unsafe.Pointer(&newState)), 0, 0, 0); err != 0 {
+		return err
+	}
+
+	return nil
+}
+
+func (rr *RuneReader) RestoreTermMode() error {
+	if _, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(rr.stdio.In.Fd()), ioctlWriteTermios, uintptr(unsafe.Pointer(&rr.state.term)), 0, 0, 0); err != 0 {
+		return err
+	}
+	return nil
+}
+
+// ReadRune Parse escape sequences such as ESC [ A for arrow keys.
+// See https://vt100.net/docs/vt102-ug/appendixc.html
+func (rr *RuneReader) ReadRune() (rune, int, error) {
+	r, size, err := rr.state.reader.ReadRune()
+	if err != nil {
+		return r, size, err
+	}
+
+	if r != KeyEscape {
+		return r, size, err
+	}
+
+	if rr.state.reader.Buffered() == 0 {
+		// no more characters so must be `Esc` key
+		return KeyEscape, 1, nil
+	}
+
+	r, size, err = rr.state.reader.ReadRune()
+	if err != nil {
+		return r, size, err
+	}
+
+	// ESC O ... or ESC [ ...?
+	if r != normalKeypad && r != applicationKeypad {
+		return r, size, fmt.Errorf("unexpected escape sequence from terminal: %q", []rune{KeyEscape, r})
+	}
+
+	keypad := r
+
+	r, size, err = rr.state.reader.ReadRune()
+	if err != nil {
+		return r, size, err
+	}
+
+	switch r {
+	case 'A': // ESC [ A or ESC O A
+		return KeyArrowUp, 1, nil
+	case 'B': // ESC [ B or ESC O B
+		return KeyArrowDown, 1, nil
+	case 'C': // ESC [ C or ESC O C
+		return KeyArrowRight, 1, nil
+	case 'D': // ESC [ D or ESC O D
+		return KeyArrowLeft, 1, nil
+	case 'F': // ESC [ F or ESC O F
+		return SpecialKeyEnd, 1, nil
+	case 'H': // ESC [ H or ESC O H
+		return SpecialKeyHome, 1, nil
+	case '3': // ESC [ 3
+		if keypad == normalKeypad {
+			// discard the following '~' key from buffer
+			_, _ = rr.state.reader.Discard(1)
+			return SpecialKeyDelete, 1, nil
+		}
+	}
+
+	// discard the following '~' key from buffer
+	_, _ = rr.state.reader.Discard(1)
+	return IgnoreKey, 1, nil
+}