containerd/vendor/github.com/crosbymichael/console/tc.go

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// +build linux
package console
import (
"fmt"
"os"
"syscall"
"unsafe"
)
func tcget(fd uintptr, p *syscall.Termios) error {
return ioctl(fd, syscall.TCGETS, uintptr(unsafe.Pointer(p)))
}
func tcset(fd uintptr, p *syscall.Termios) error {
return ioctl(fd, syscall.TCSETS, uintptr(unsafe.Pointer(p)))
}
func ioctl(fd, flag, data uintptr) error {
if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, flag, data); err != 0 {
return err
}
return nil
}
// unlockpt unlocks the slave pseudoterminal device corresponding to the master pseudoterminal referred to by f.
// unlockpt should be called before opening the slave side of a pty.
func unlockpt(f *os.File) error {
var u int32
return ioctl(f.Fd(), syscall.TIOCSPTLCK, uintptr(unsafe.Pointer(&u)))
}
// ptsname retrieves the name of the first available pts for the given master.
func ptsname(f *os.File) (string, error) {
var n int32
if err := ioctl(f.Fd(), syscall.TIOCGPTN, uintptr(unsafe.Pointer(&n))); err != nil {
return "", err
}
return fmt.Sprintf("/dev/pts/%d", n), nil
}
func saneTerminal(f *os.File) error {
// Go doesn't have a wrapper for any of the termios ioctls.
var termios syscall.Termios
if err := tcget(f.Fd(), &termios); err != nil {
return err
}
// Set -onlcr so we don't have to deal with \r.
termios.Oflag &^= syscall.ONLCR
return tcset(f.Fd(), &termios)
}