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// +build linux darwin freebsd netbsd openbsd solaris dragonfly
// +build !appengine
package pb
import (
"errors"
"fmt"
"os"
"os/signal"
"runtime"
"sync"
"syscall"
"unsafe"
)
const (
TIOCGWINSZ = 0x5413
TIOCGWINSZ_OSX = 1074295912
)
var tty *os.File
var ErrPoolWasStarted = errors.New("Bar pool was started")
var echoLocked bool
var echoLockMutex sync.Mutex
func init() {
var err error
tty, err = os.Open("/dev/tty")
if err != nil {
tty = os.Stdin
}
}
// terminalWidth returns width of the terminal.
func terminalWidth() (int, error) {
w := new(window)
tio := syscall.TIOCGWINSZ
if runtime.GOOS == "darwin" {
tio = TIOCGWINSZ_OSX
}
res, _, err := syscall.Syscall(sysIoctl,
tty.Fd(),
uintptr(tio),
uintptr(unsafe.Pointer(w)),
)
if int(res) == -1 {
return 0, err
}
return int(w.Col), nil
}
var oldState syscall.Termios
func lockEcho() (quit chan int, err error) {
echoLockMutex.Lock()
defer echoLockMutex.Unlock()
if echoLocked {
err = ErrPoolWasStarted
return
}
echoLocked = true
fd := tty.Fd()
if _, _, e := syscall.Syscall6(sysIoctl, fd, ioctlReadTermios, uintptr(unsafe.Pointer(&oldState)), 0, 0, 0); e != 0 {
err = fmt.Errorf("Can't get terminal settings: %v", e)
return
}
newState := oldState
newState.Lflag &^= syscall.ECHO
newState.Lflag |= syscall.ICANON | syscall.ISIG
newState.Iflag |= syscall.ICRNL
if _, _, e := syscall.Syscall6(sysIoctl, fd, ioctlWriteTermios, uintptr(unsafe.Pointer(&newState)), 0, 0, 0); e != 0 {
err = fmt.Errorf("Can't set terminal settings: %v", e)
return
}
quit = make(chan int, 1)
go catchTerminate(quit)
return
}
func unlockEcho() (err error) {
echoLockMutex.Lock()
defer echoLockMutex.Unlock()
if !echoLocked {
return
}
echoLocked = false
fd := tty.Fd()
if _, _, e := syscall.Syscall6(sysIoctl, fd, ioctlWriteTermios, uintptr(unsafe.Pointer(&oldState)), 0, 0, 0); e != 0 {
err = fmt.Errorf("Can't set terminal settings")
}
return
}
// listen exit signals and restore terminal state
func catchTerminate(quit chan int) {
sig := make(chan os.Signal, 1)
signal.Notify(sig, os.Interrupt, syscall.SIGQUIT, syscall.SIGTERM, syscall.SIGKILL)
defer signal.Stop(sig)
select {
case <-quit:
unlockEcho()
case <-sig:
unlockEcho()
}
}
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