1 files changed, 102 insertions, 0 deletions
diff --git a/libgo/go/exp/terminal/util.go b/libgo/go/exp/terminal/util.go
new file mode 100644
index 00000000000..03035673869
--- /dev/null
+++ b/libgo/go/exp/terminal/util.go
@@ -0,0 +1,102 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package terminal provides support functions for dealing with terminals, as
+// commonly found on UNIX systems.
+//
+// Putting a terminal into raw mode is the most common requirement:
+//
+// 	oldState, err := terminal.MakeRaw(0)
+// 	if err != nil {
+// 	        panic(err.String())
+// 	}
+// 	defer terminal.Restore(0, oldState)
+package terminal
+
+import (
+	"io"
+	"syscall"
+)
+
+// State contains the state of a terminal.
+type State struct {
+	termios syscall.Termios
+}
+
+// IsTerminal returns true if the given file descriptor is a terminal.
+func IsTerminal(fd int) bool {
+	var termios syscall.Termios
+	err := syscall.Tcgetattr(fd, &termios)
+	return err == nil
+}
+
+// MakeRaw put the terminal connected to the given file descriptor into raw
+// mode and returns the previous state of the terminal so that it can be
+// restored.
+func MakeRaw(fd int) (*State, error) {
+	var oldState State
+	if err := syscall.Tcgetattr(fd, &oldState.termios); err != nil {
+		return nil, err
+	}
+
+	newState := oldState.termios
+	newState.Iflag &^= syscall.ISTRIP | syscall.INLCR | syscall.ICRNL | syscall.IGNCR | syscall.IXON | syscall.IXOFF
+	newState.Lflag &^= syscall.ECHO | syscall.ICANON | syscall.ISIG
+	if err := syscall.Tcsetattr(fd, syscall.TCSANOW, &newState); err != nil {
+		return nil, err
+	}
+
+	return &oldState, nil
+}
+
+// Restore restores the terminal connected to the given file descriptor to a
+// previous state.
+func Restore(fd int, state *State) error {
+	err := syscall.Tcsetattr(fd, syscall.TCSANOW, &state.termios)
+	return err
+}
+
+// ReadPassword reads a line of input from a terminal without local echo.  This
+// is commonly used for inputting passwords and other sensitive data. The slice
+// returned does not include the \n.
+func ReadPassword(fd int) ([]byte, error) {
+	var oldState syscall.Termios
+	if err := syscall.Tcgetattr(fd, &oldState); err != nil {
+		return nil, err
+	}
+
+	newState := oldState
+	newState.Lflag &^= syscall.ECHO
+	if err := syscall.Tcsetattr(fd, syscall.TCSANOW, &newState); err != nil {
+		return nil, err
+	}
+
+	defer func() {
+		syscall.Tcsetattr(fd, syscall.TCSANOW, &oldState)
+	}()
+
+	var buf [16]byte
+	var ret []byte
+	for {
+		n, err := syscall.Read(fd, buf[:])
+		if err != nil {
+			return nil, err
+		}
+		if n == 0 {
+			if len(ret) == 0 {
+				return nil, io.EOF
+			}
+			break
+		}
+		if buf[n-1] == '\n' {
+			n--
+		}
+		ret = append(ret, buf[:n]...)
+		if n < len(buf) {
+			break
+		}
+	}
+
+	return ret, nil
+}