1package pty
2
3import (
4	"os"
5	"syscall"
6	"unsafe"
7)
8
9func open() (pty, tty *os.File, err error) {
10	/*
11	 * from ptm(4):
12	 * The PTMGET command allocates a free pseudo terminal, changes its
13	 * ownership to the caller, revokes the access privileges for all previous
14	 * users, opens the file descriptors for the master and slave devices and
15	 * returns them to the caller in struct ptmget.
16	 */
17
18	p, err := os.OpenFile("/dev/ptm", os.O_RDWR|syscall.O_CLOEXEC, 0)
19	if err != nil {
20		return nil, nil, err
21	}
22	defer p.Close()
23
24	var ptm ptmget
25	if err := ioctl(p.Fd(), uintptr(ioctl_PTMGET), uintptr(unsafe.Pointer(&ptm))); err != nil {
26		return nil, nil, err
27	}
28
29	pty = os.NewFile(uintptr(ptm.Cfd), "/dev/ptm")
30	tty = os.NewFile(uintptr(ptm.Sfd), "/dev/ptm")
31
32	return pty, tty, nil
33}
34