go.crypto: add exp/terminal as code.google.com/p/go.crypto/ssh/terminal.
This removes the sole "exp/foo" import in the Go subrepos.
A separate CL will remove exp/terminal from the standard Go repository.
R=golang-dev, dave, r
CC=golang-dev
https://golang.org/cl/5966045
diff --git a/ssh/terminal/util.go b/ssh/terminal/util.go
new file mode 100644
index 0000000..67b287c
--- /dev/null
+++ b/ssh/terminal/util.go
@@ -0,0 +1,115 @@
+// 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.
+
+// +build linux
+
+// 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)
+// }
+// defer terminal.Restore(0, oldState)
+package terminal
+
+import (
+ "io"
+ "syscall"
+ "unsafe"
+)
+
+// 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.Syscall6(syscall.SYS_IOCTL, uintptr(fd), uintptr(syscall.TCGETS), uintptr(unsafe.Pointer(&termios)), 0, 0, 0)
+ return err == 0
+}
+
+// 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.Syscall6(syscall.SYS_IOCTL, uintptr(fd), uintptr(syscall.TCGETS), uintptr(unsafe.Pointer(&oldState.termios)), 0, 0, 0); err != 0 {
+ 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.Syscall6(syscall.SYS_IOCTL, uintptr(fd), uintptr(syscall.TCSETS), uintptr(unsafe.Pointer(&newState)), 0, 0, 0); err != 0 {
+ 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.Syscall6(syscall.SYS_IOCTL, uintptr(fd), uintptr(syscall.TCSETS), uintptr(unsafe.Pointer(&state.termios)), 0, 0, 0)
+ return err
+}
+
+// GetSize returns the dimensions of the given terminal.
+func GetSize(fd int) (width, height int, err error) {
+ var dimensions [4]uint16
+
+ if _, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), uintptr(syscall.TIOCGWINSZ), uintptr(unsafe.Pointer(&dimensions)), 0, 0, 0); err != 0 {
+ return -1, -1, err
+ }
+ return int(dimensions[1]), int(dimensions[0]), nil
+}
+
+// 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.Syscall6(syscall.SYS_IOCTL, uintptr(fd), uintptr(syscall.TCGETS), uintptr(unsafe.Pointer(&oldState)), 0, 0, 0); err != 0 {
+ return nil, err
+ }
+
+ newState := oldState
+ newState.Lflag &^= syscall.ECHO
+ if _, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), uintptr(syscall.TCSETS), uintptr(unsafe.Pointer(&newState)), 0, 0, 0); err != 0 {
+ return nil, err
+ }
+
+ defer func() {
+ syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), uintptr(syscall.TCSETS), uintptr(unsafe.Pointer(&oldState)), 0, 0, 0)
+ }()
+
+ 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
+}
