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)
17package terminal
18
19import (
20 "os"
21
22 "golang.org/x/sys/windows"
23)
24
25type State struct {
26 mode uint32
27}
28
29// IsTerminal returns true if the given file descriptor is a terminal.
30func 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.
39func 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.
53func 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.
63func Restore(fd int, state *State) error {
64 return windows.SetConsoleMode(windows.Handle(fd), state.mode)
65}
66
67// GetSize returns the dimensions of the given terminal.
68func GetSize(fd int) (width, height int, err error) {
69 var info windows.ConsoleScreenBufferInfo
70 if err := windows.GetConsoleScreenBufferInfo(windows.Handle(fd), &info); err != nil {
71 return 0, 0, err
72 }
73 return int(info.Size.X), int(info.Size.Y), nil
74}
75
76// ReadPassword reads a line of input from a terminal without local echo. This
77// is commonly used for inputting passwords and other sensitive data. The slice
78// returned does not include the \n.
79func ReadPassword(fd int) ([]byte, error) {
80 var st uint32
81 if err := windows.GetConsoleMode(windows.Handle(fd), &st); err != nil {
82 return nil, err
83 }
84 old := st
85
86 st &^= (windows.ENABLE_ECHO_INPUT)
87 st |= (windows.ENABLE_PROCESSED_INPUT | windows.ENABLE_LINE_INPUT | windows.ENABLE_PROCESSED_OUTPUT)
88 if err := windows.SetConsoleMode(windows.Handle(fd), st); err != nil {
89 return nil, err
90 }
91
92 defer windows.SetConsoleMode(windows.Handle(fd), old)
93
94 var h windows.Handle
95 p, _ := windows.GetCurrentProcess()
96 if err := windows.DuplicateHandle(p, windows.Handle(fd), p, &h, 0, false, windows.DUPLICATE_SAME_ACCESS); err != nil {
97 return nil, err
98 }
99
100 f := os.NewFile(uintptr(h), "stdin")
101 defer f.Close()
102 return readPasswordLine(f)
103}