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// +build linux darwin freebsd netbsd openbsd solaris dragonfly
// +build !appengine !js
package pb
import (
"errors"
"fmt"
"os"
"os/signal"
"sync"
"syscall"
"golang.org/x/sys/unix"
)
var ErrPoolWasStarted = errors.New("Bar pool was started")
var (
echoLockMutex sync.Mutex
origTermStatePtr *unix.Termios
tty *os.File
istty bool
)
func init() {
echoLockMutex.Lock()
defer echoLockMutex.Unlock()
var err error
tty, err = os.Open("/dev/tty")
istty = true
if err != nil {
tty = os.Stdin
istty = false
}
}
// terminalWidth returns width of the terminal.
func terminalWidth() (int, error) {
if !istty {
return 0, errors.New("Not Supported")
}
echoLockMutex.Lock()
defer echoLockMutex.Unlock()
fd := int(tty.Fd())
ws, err := unix.IoctlGetWinsize(fd, unix.TIOCGWINSZ)
if err != nil {
return 0, err
}
return int(ws.Col), nil
}
func lockEcho() (shutdownCh chan struct{}, err error) {
echoLockMutex.Lock()
defer echoLockMutex.Unlock()
if istty {
if origTermStatePtr != nil {
return shutdownCh, ErrPoolWasStarted
}
fd := int(tty.Fd())
origTermStatePtr, err = unix.IoctlGetTermios(fd, ioctlReadTermios)
if err != nil {
return nil, fmt.Errorf("Can't get terminal settings: %v", err)
}
oldTermios := *origTermStatePtr
newTermios := oldTermios
newTermios.Lflag &^= syscall.ECHO
newTermios.Lflag |= syscall.ICANON | syscall.ISIG
newTermios.Iflag |= syscall.ICRNL
if err := unix.IoctlSetTermios(fd, ioctlWriteTermios, &newTermios); err != nil {
return nil, fmt.Errorf("Can't set terminal settings: %v", err)
}
}
shutdownCh = make(chan struct{})
go catchTerminate(shutdownCh)
return
}
func unlockEcho() error {
echoLockMutex.Lock()
defer echoLockMutex.Unlock()
if istty {
if origTermStatePtr == nil {
return nil
}
fd := int(tty.Fd())
if err := unix.IoctlSetTermios(fd, ioctlWriteTermios, origTermStatePtr); err != nil {
return fmt.Errorf("Can't set terminal settings: %v", err)
}
}
origTermStatePtr = nil
return nil
}
// listen exit signals and restore terminal state
func catchTerminate(shutdownCh chan struct{}) {
sig := make(chan os.Signal, 1)
signal.Notify(sig, os.Interrupt, syscall.SIGQUIT, syscall.SIGTERM, syscall.SIGKILL)
defer signal.Stop(sig)
select {
case <-shutdownCh:
unlockEcho()
case <-sig:
unlockEcho()
}
}
|
