pkg/system/pty_linux.go
Guillaume J. Charmes a304eab9d4 Improve general quality of libcontainer
Docker-DCO-1.1-Signed-off-by: Guillaume J. Charmes <guillaume.charmes@docker.com> (github: creack)
2014-02-21 14:56:15 -08:00

31 lines
931 B
Go

package system
import (
"fmt"
"os"
"syscall"
"unsafe"
)
// 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 pseudoterminal.
func Unlockpt(f *os.File) error {
var u int
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 int
if err := Ioctl(f.Fd(), syscall.TIOCGPTN, uintptr(unsafe.Pointer(&n))); err != nil {
return "", err
}
return fmt.Sprintf("/dev/pts/%d", n), nil
}
// OpenPtmx opens /dev/ptmx, i.e. the PTY master.
func OpenPtmx() (*os.File, error) {
// O_NOCTTY and O_CLOEXEC are not present in os package so we use the syscall's one for all.
return os.OpenFile("/dev/ptmx", syscall.O_RDONLY|syscall.O_NOCTTY|syscall.O_CLOEXEC, 0)
}