1// Copyright 2019 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// +build aix darwin dragonfly freebsd linux netbsd openbsd zos
6
7package term
8
9import (
10	"golang.org/x/sys/unix"
11)
12
13type state struct {
14	termios unix.Termios
15}
16
17func isTerminal(fd int) bool {
18	_, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
19	return err == nil
20}
21
22func makeRaw(fd int) (*State, error) {
23	termios, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
24	if err != nil {
25		return nil, err
26	}
27
28	oldState := State{state{termios: *termios}}
29
30	// This attempts to replicate the behaviour documented for cfmakeraw in
31	// the termios(3) manpage.
32	termios.Iflag &^= unix.IGNBRK | unix.BRKINT | unix.PARMRK | unix.ISTRIP | unix.INLCR | unix.IGNCR | unix.ICRNL | unix.IXON
33	termios.Oflag &^= unix.OPOST
34	termios.Lflag &^= unix.ECHO | unix.ECHONL | unix.ICANON | unix.ISIG | unix.IEXTEN
35	termios.Cflag &^= unix.CSIZE | unix.PARENB
36	termios.Cflag |= unix.CS8
37	termios.Cc[unix.VMIN] = 1
38	termios.Cc[unix.VTIME] = 0
39	if err := unix.IoctlSetTermios(fd, ioctlWriteTermios, termios); err != nil {
40		return nil, err
41	}
42
43	return &oldState, nil
44}
45
46func getState(fd int) (*State, error) {
47	termios, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
48	if err != nil {
49		return nil, err
50	}
51
52	return &State{state{termios: *termios}}, nil
53}
54
55func restore(fd int, state *State) error {
56	return unix.IoctlSetTermios(fd, ioctlWriteTermios, &state.termios)
57}
58
59func getSize(fd int) (width, height int, err error) {
60	ws, err := unix.IoctlGetWinsize(fd, unix.TIOCGWINSZ)
61	if err != nil {
62		return -1, -1, err
63	}
64	return int(ws.Col), int(ws.Row), nil
65}
66
67// passwordReader is an io.Reader that reads from a specific file descriptor.
68type passwordReader int
69
70func (r passwordReader) Read(buf []byte) (int, error) {
71	return unix.Read(int(r), buf)
72}
73
74func readPassword(fd int) ([]byte, error) {
75	termios, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
76	if err != nil {
77		return nil, err
78	}
79
80	newState := *termios
81	newState.Lflag &^= unix.ECHO
82	newState.Lflag |= unix.ICANON | unix.ISIG
83	newState.Iflag |= unix.ICRNL
84	if err := unix.IoctlSetTermios(fd, ioctlWriteTermios, &newState); err != nil {
85		return nil, err
86	}
87
88	defer unix.IoctlSetTermios(fd, ioctlWriteTermios, termios)
89
90	return readPasswordLine(passwordReader(fd))
91}
92