github.com/glycerine/xcryptossh@v7.0.4+incompatible/terminal/util_windows.go (about)

     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  	"golang.org/x/sys/windows"
    21  )
    22  
    23  type State struct {
    24  	mode uint32
    25  }
    26  
    27  // IsTerminal returns true if the given file descriptor is a terminal.
    28  func IsTerminal(fd int) bool {
    29  	var st uint32
    30  	err := windows.GetConsoleMode(windows.Handle(fd), &st)
    31  	return err == nil
    32  }
    33  
    34  // MakeRaw put the terminal connected to the given file descriptor into raw
    35  // mode and returns the previous state of the terminal so that it can be
    36  // restored.
    37  func MakeRaw(fd int) (*State, error) {
    38  	var st uint32
    39  	if err := windows.GetConsoleMode(windows.Handle(fd), &st); err != nil {
    40  		return nil, err
    41  	}
    42  	raw := st &^ (windows.ENABLE_ECHO_INPUT | windows.ENABLE_PROCESSED_INPUT | windows.ENABLE_LINE_INPUT | windows.ENABLE_PROCESSED_OUTPUT)
    43  	if err := windows.SetConsoleMode(windows.Handle(fd), raw); err != nil {
    44  		return nil, err
    45  	}
    46  	return &State{st}, nil
    47  }
    48  
    49  // GetState returns the current state of a terminal which may be useful to
    50  // restore the terminal after a signal.
    51  func GetState(fd int) (*State, error) {
    52  	var st uint32
    53  	if err := windows.GetConsoleMode(windows.Handle(fd), &st); err != nil {
    54  		return nil, err
    55  	}
    56  	return &State{st}, nil
    57  }
    58  
    59  // Restore restores the terminal connected to the given file descriptor to a
    60  // previous state.
    61  func Restore(fd int, state *State) error {
    62  	return windows.SetConsoleMode(windows.Handle(fd), state.mode)
    63  }
    64  
    65  // GetSize returns the dimensions of the given terminal.
    66  func GetSize(fd int) (width, height int, err error) {
    67  	var info windows.ConsoleScreenBufferInfo
    68  	if err := windows.GetConsoleScreenBufferInfo(windows.Handle(fd), &info); err != nil {
    69  		return 0, 0, err
    70  	}
    71  	return int(info.Size.X), int(info.Size.Y), nil
    72  }
    73  
    74  // passwordReader is an io.Reader that reads from a specific Windows HANDLE.
    75  type passwordReader int
    76  
    77  func (r passwordReader) Read(buf []byte) (int, error) {
    78  	return windows.Read(windows.Handle(r), buf)
    79  }
    80  
    81  // ReadPassword reads a line of input from a terminal without local echo.  This
    82  // is commonly used for inputting passwords and other sensitive data. The slice
    83  // returned does not include the \n.
    84  func ReadPassword(fd int) ([]byte, error) {
    85  	var st uint32
    86  	if err := windows.GetConsoleMode(windows.Handle(fd), &st); err != nil {
    87  		return nil, err
    88  	}
    89  	old := st
    90  
    91  	st &^= (windows.ENABLE_ECHO_INPUT)
    92  	st |= (windows.ENABLE_PROCESSED_INPUT | windows.ENABLE_LINE_INPUT | windows.ENABLE_PROCESSED_OUTPUT)
    93  	if err := windows.SetConsoleMode(windows.Handle(fd), st); err != nil {
    94  		return nil, err
    95  	}
    96  
    97  	defer func() {
    98  		windows.SetConsoleMode(windows.Handle(fd), old)
    99  	}()
   100  
   101  	return readPasswordLine(passwordReader(fd))
   102  }