David K. Bainbridge | bd6b288 | 2021-08-26 13:31:02 +0000 | [diff] [blame] | 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 | package term |
| 6 | |
| 7 | import ( |
| 8 | "io" |
| 9 | "syscall" |
| 10 | |
| 11 | "golang.org/x/sys/unix" |
| 12 | ) |
| 13 | |
| 14 | // State contains the state of a terminal. |
| 15 | type state struct { |
| 16 | termios unix.Termios |
| 17 | } |
| 18 | |
| 19 | func isTerminal(fd int) bool { |
| 20 | _, err := unix.IoctlGetTermio(fd, unix.TCGETA) |
| 21 | return err == nil |
| 22 | } |
| 23 | |
| 24 | func readPassword(fd int) ([]byte, error) { |
| 25 | // see also: http://src.illumos.org/source/xref/illumos-gate/usr/src/lib/libast/common/uwin/getpass.c |
| 26 | val, err := unix.IoctlGetTermios(fd, unix.TCGETS) |
| 27 | if err != nil { |
| 28 | return nil, err |
| 29 | } |
| 30 | oldState := *val |
| 31 | |
| 32 | newState := oldState |
| 33 | newState.Lflag &^= syscall.ECHO |
| 34 | newState.Lflag |= syscall.ICANON | syscall.ISIG |
| 35 | newState.Iflag |= syscall.ICRNL |
| 36 | err = unix.IoctlSetTermios(fd, unix.TCSETS, &newState) |
| 37 | if err != nil { |
| 38 | return nil, err |
| 39 | } |
| 40 | |
| 41 | defer unix.IoctlSetTermios(fd, unix.TCSETS, &oldState) |
| 42 | |
| 43 | var buf [16]byte |
| 44 | var ret []byte |
| 45 | for { |
| 46 | n, err := syscall.Read(fd, buf[:]) |
| 47 | if err != nil { |
| 48 | return nil, err |
| 49 | } |
| 50 | if n == 0 { |
| 51 | if len(ret) == 0 { |
| 52 | return nil, io.EOF |
| 53 | } |
| 54 | break |
| 55 | } |
| 56 | if buf[n-1] == '\n' { |
| 57 | n-- |
| 58 | } |
| 59 | ret = append(ret, buf[:n]...) |
| 60 | if n < len(buf) { |
| 61 | break |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | return ret, nil |
| 66 | } |
| 67 | |
| 68 | func makeRaw(fd int) (*State, error) { |
| 69 | // see http://cr.illumos.org/~webrev/andy_js/1060/ |
| 70 | termios, err := unix.IoctlGetTermios(fd, unix.TCGETS) |
| 71 | if err != nil { |
| 72 | return nil, err |
| 73 | } |
| 74 | |
| 75 | oldState := State{state{termios: *termios}} |
| 76 | |
| 77 | termios.Iflag &^= unix.IGNBRK | unix.BRKINT | unix.PARMRK | unix.ISTRIP | unix.INLCR | unix.IGNCR | unix.ICRNL | unix.IXON |
| 78 | termios.Oflag &^= unix.OPOST |
| 79 | termios.Lflag &^= unix.ECHO | unix.ECHONL | unix.ICANON | unix.ISIG | unix.IEXTEN |
| 80 | termios.Cflag &^= unix.CSIZE | unix.PARENB |
| 81 | termios.Cflag |= unix.CS8 |
| 82 | termios.Cc[unix.VMIN] = 1 |
| 83 | termios.Cc[unix.VTIME] = 0 |
| 84 | |
| 85 | if err := unix.IoctlSetTermios(fd, unix.TCSETS, termios); err != nil { |
| 86 | return nil, err |
| 87 | } |
| 88 | |
| 89 | return &oldState, nil |
| 90 | } |
| 91 | |
| 92 | func restore(fd int, oldState *State) error { |
| 93 | return unix.IoctlSetTermios(fd, unix.TCSETS, &oldState.termios) |
| 94 | } |
| 95 | |
| 96 | func getState(fd int) (*State, error) { |
| 97 | termios, err := unix.IoctlGetTermios(fd, unix.TCGETS) |
| 98 | if err != nil { |
| 99 | return nil, err |
| 100 | } |
| 101 | |
| 102 | return &State{state{termios: *termios}}, nil |
| 103 | } |
| 104 | |
| 105 | func getSize(fd int) (width, height int, err error) { |
| 106 | ws, err := unix.IoctlGetWinsize(fd, unix.TIOCGWINSZ) |
| 107 | if err != nil { |
| 108 | return 0, 0, err |
| 109 | } |
| 110 | return int(ws.Col), int(ws.Row), nil |
| 111 | } |