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

112 lines
2.8 KiB
Go

// +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"
)
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
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
}
func (rr *RuneReader) ReadRune() (rune, int, error) {
r, size, err := rr.state.reader.ReadRune()
if err != nil {
return r, size, err
}
// parse ^[ sequences to look for arrow keys
if r == '\033' {
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
}
if r != '[' {
return r, size, fmt.Errorf("Unexpected Escape Sequence: %q", []rune{'\033', r})
}
r, size, err = rr.state.reader.ReadRune()
if err != nil {
return r, size, err
}
switch r {
case 'D':
return KeyArrowLeft, 1, nil
case 'C':
return KeyArrowRight, 1, nil
case 'A':
return KeyArrowUp, 1, nil
case 'B':
return KeyArrowDown, 1, nil
case 'H': // Home button
return SpecialKeyHome, 1, nil
case 'F': // End button
return SpecialKeyEnd, 1, nil
case '3': // Delete Button
// discard the following '~' key from buffer
rr.state.reader.Discard(1)
return SpecialKeyDelete, 1, nil
default:
// discard the following '~' key from buffer
rr.state.reader.Discard(1)
return IgnoreKey, 1, nil
}
return r, size, fmt.Errorf("Unknown Escape Sequence: %q", []rune{'\033', '[', r})
}
return r, size, err
}