x/ref: Add internal packages for rps and tunnel.
examples/rps/common -> examples/rps/internal
examples/tunnel/tunnelutil -> examples/tunnel/internal
Change-Id: Ie1e721cc7b0b89a3cc2dfe3d9df892955b0f0ea4
diff --git a/examples/tunnel/internal/terminal.go b/examples/tunnel/internal/terminal.go
new file mode 100644
index 0000000..db08dba
--- /dev/null
+++ b/examples/tunnel/internal/terminal.go
@@ -0,0 +1,105 @@
+// Copyright 2015 The Vanadium 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 internal defines common types and functions used by both tunnel
+// clients and servers.
+package internal
+
+import (
+ "errors"
+ "os/exec"
+ "strings"
+ "syscall"
+ "unsafe"
+
+ "v.io/x/lib/vlog"
+)
+
+// Winsize defines the window size used by ioctl TIOCGWINSZ and TIOCSWINSZ.
+type Winsize struct {
+ Row uint16
+ Col uint16
+ Xpixel uint16
+ Ypixel uint16
+}
+
+// SetWindowSize sets the terminal's window size.
+func SetWindowSize(fd uintptr, ws Winsize) error {
+ vlog.Infof("Setting window size: %v", ws)
+ ret, _, _ := syscall.Syscall(
+ syscall.SYS_IOCTL,
+ fd,
+ uintptr(syscall.TIOCSWINSZ),
+ uintptr(unsafe.Pointer(&ws)))
+ if int(ret) == -1 {
+ return errors.New("ioctl(TIOCSWINSZ) failed")
+ }
+ return nil
+}
+
+// GetWindowSize gets the terminal's window size.
+func GetWindowSize() (*Winsize, error) {
+ ws := &Winsize{}
+ ret, _, _ := syscall.Syscall(
+ syscall.SYS_IOCTL,
+ uintptr(syscall.Stdin),
+ uintptr(syscall.TIOCGWINSZ),
+ uintptr(unsafe.Pointer(ws)))
+ if int(ret) == -1 {
+ return nil, errors.New("ioctl(TIOCGWINSZ) failed")
+ }
+ return ws, nil
+}
+
+// EnterRawTerminalMode uses stty to enter the terminal into raw mode; stdin is
+// unbuffered, local echo of input characters is disabled, and special signal
+// characters are disabled. Returns a string which may be passed to
+// RestoreTerminalSettings to restore to the original terminal settings.
+func EnterRawTerminalMode() string {
+ var savedBytes []byte
+ var err error
+ if savedBytes, err = exec.Command("stty", "-F", "/dev/tty", "-g").Output(); err != nil {
+ vlog.Infof("Failed to save terminal settings: %q (%v)", savedBytes, err)
+ }
+ saved := strings.TrimSpace(string(savedBytes))
+
+ args := []string{
+ "-F", "/dev/tty",
+ // Don't buffer stdin. Read characters as they are typed.
+ "-icanon", "min", "1", "time", "0",
+ // Turn off local echo of input characters.
+ "-echo", "-echoe", "-echok", "-echonl",
+ // Disable interrupt, quit, and suspend special characters.
+ "-isig",
+ // Ignore characters with parity errors.
+ "ignpar",
+ // Disable translate newline to carriage return.
+ "-inlcr",
+ // Disable ignore carriage return.
+ "-igncr",
+ // Disable translate carriage return to newline.
+ "-icrnl",
+ // Disable flow control.
+ "-ixon", "-ixany", "-ixoff",
+ // Disable non-POSIX special characters.
+ "-iexten",
+ }
+ if out, err := exec.Command("stty", args...).CombinedOutput(); err != nil {
+ vlog.Infof("stty failed (%v) (%q)", err, out)
+ }
+
+ return string(saved)
+}
+
+// RestoreTerminalSettings uses stty to restore the terminal to the original
+// settings, taking the saved settings returned by EnterRawTerminalMode.
+func RestoreTerminalSettings(saved string) {
+ args := []string{
+ "-F", "/dev/tty",
+ saved,
+ }
+ if out, err := exec.Command("stty", args...).CombinedOutput(); err != nil {
+ vlog.Infof("stty failed (%v) (%q)", err, out)
+ }
+}
