Zack Williams | e940c7a | 2019-08-21 14:25:39 -0700 | [diff] [blame] | 1 | // Copyright 2011 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 windows |
| 6 | |
| 7 | // Package terminal provides support functions for dealing with terminals, as |
| 8 | // commonly found on UNIX systems. |
| 9 | // |
| 10 | // Putting a terminal into raw mode is the most common requirement: |
| 11 | // |
| 12 | // oldState, err := terminal.MakeRaw(0) |
| 13 | // if err != nil { |
| 14 | // panic(err) |
| 15 | // } |
| 16 | // defer terminal.Restore(0, oldState) |
| 17 | package terminal |
| 18 | |
| 19 | import ( |
| 20 | "os" |
| 21 | |
| 22 | "golang.org/x/sys/windows" |
| 23 | ) |
| 24 | |
| 25 | type State struct { |
| 26 | mode uint32 |
| 27 | } |
| 28 | |
| 29 | // IsTerminal returns whether the given file descriptor is a terminal. |
| 30 | func IsTerminal(fd int) bool { |
| 31 | var st uint32 |
| 32 | err := windows.GetConsoleMode(windows.Handle(fd), &st) |
| 33 | return err == nil |
| 34 | } |
| 35 | |
| 36 | // MakeRaw put the terminal connected to the given file descriptor into raw |
| 37 | // mode and returns the previous state of the terminal so that it can be |
| 38 | // restored. |
| 39 | func MakeRaw(fd int) (*State, error) { |
| 40 | var st uint32 |
| 41 | if err := windows.GetConsoleMode(windows.Handle(fd), &st); err != nil { |
| 42 | return nil, err |
| 43 | } |
| 44 | raw := st &^ (windows.ENABLE_ECHO_INPUT | windows.ENABLE_PROCESSED_INPUT | windows.ENABLE_LINE_INPUT | windows.ENABLE_PROCESSED_OUTPUT) |
| 45 | if err := windows.SetConsoleMode(windows.Handle(fd), raw); err != nil { |
| 46 | return nil, err |
| 47 | } |
| 48 | return &State{st}, nil |
| 49 | } |
| 50 | |
| 51 | // GetState returns the current state of a terminal which may be useful to |
| 52 | // restore the terminal after a signal. |
| 53 | func GetState(fd int) (*State, error) { |
| 54 | var st uint32 |
| 55 | if err := windows.GetConsoleMode(windows.Handle(fd), &st); err != nil { |
| 56 | return nil, err |
| 57 | } |
| 58 | return &State{st}, nil |
| 59 | } |
| 60 | |
| 61 | // Restore restores the terminal connected to the given file descriptor to a |
| 62 | // previous state. |
| 63 | func Restore(fd int, state *State) error { |
| 64 | return windows.SetConsoleMode(windows.Handle(fd), state.mode) |
| 65 | } |
| 66 | |
| 67 | // GetSize returns the visible dimensions of the given terminal. |
| 68 | // |
| 69 | // These dimensions don't include any scrollback buffer height. |
| 70 | func GetSize(fd int) (width, height int, err error) { |
| 71 | var info windows.ConsoleScreenBufferInfo |
| 72 | if err := windows.GetConsoleScreenBufferInfo(windows.Handle(fd), &info); err != nil { |
| 73 | return 0, 0, err |
| 74 | } |
| 75 | return int(info.Window.Right - info.Window.Left + 1), int(info.Window.Bottom - info.Window.Top + 1), nil |
| 76 | } |
| 77 | |
| 78 | // ReadPassword reads a line of input from a terminal without local echo. This |
| 79 | // is commonly used for inputting passwords and other sensitive data. The slice |
| 80 | // returned does not include the \n. |
| 81 | func ReadPassword(fd int) ([]byte, error) { |
| 82 | var st uint32 |
| 83 | if err := windows.GetConsoleMode(windows.Handle(fd), &st); err != nil { |
| 84 | return nil, err |
| 85 | } |
| 86 | old := st |
| 87 | |
| 88 | st &^= (windows.ENABLE_ECHO_INPUT) |
| 89 | st |= (windows.ENABLE_PROCESSED_INPUT | windows.ENABLE_LINE_INPUT | windows.ENABLE_PROCESSED_OUTPUT) |
| 90 | if err := windows.SetConsoleMode(windows.Handle(fd), st); err != nil { |
| 91 | return nil, err |
| 92 | } |
| 93 | |
| 94 | defer windows.SetConsoleMode(windows.Handle(fd), old) |
| 95 | |
| 96 | var h windows.Handle |
| 97 | p, _ := windows.GetCurrentProcess() |
| 98 | if err := windows.DuplicateHandle(p, windows.Handle(fd), p, &h, 0, false, windows.DUPLICATE_SAME_ACCESS); err != nil { |
| 99 | return nil, err |
| 100 | } |
| 101 | |
| 102 | f := os.NewFile(uintptr(h), "stdin") |
| 103 | defer f.Close() |
| 104 | return readPasswordLine(f) |
| 105 | } |