| package pty |
| |
| import ( |
| "os" |
| "strconv" |
| "syscall" |
| "unsafe" |
| ) |
| |
| func open() (pty, tty *os.File, err error) { |
| p, err := os.OpenFile("/dev/ptmx", os.O_RDWR, 0) |
| if err != nil { |
| return nil, nil, err |
| } |
| // In case of error after this point, make sure we close the ptmx fd. |
| defer func() { |
| if err != nil { |
| _ = p.Close() // Best effort. |
| } |
| }() |
| |
| sname, err := ptsname(p) |
| if err != nil { |
| return nil, nil, err |
| } |
| |
| if err := unlockpt(p); err != nil { |
| return nil, nil, err |
| } |
| |
| t, err := os.OpenFile(sname, os.O_RDWR|syscall.O_NOCTTY, 0) |
| if err != nil { |
| return nil, nil, err |
| } |
| return p, t, nil |
| } |
| |
| func ptsname(f *os.File) (string, error) { |
| var n _C_uint |
| err := ioctl(f.Fd(), syscall.TIOCGPTN, uintptr(unsafe.Pointer(&n))) |
| if err != nil { |
| return "", err |
| } |
| return "/dev/pts/" + strconv.Itoa(int(n)), nil |
| } |
| |
| func unlockpt(f *os.File) error { |
| var u _C_int |
| // use TIOCSPTLCK with a pointer to zero to clear the lock |
| return ioctl(f.Fd(), syscall.TIOCSPTLCK, uintptr(unsafe.Pointer(&u))) |
| } |