open-nomad/vendor/github.com/kr/pty/pty_dragonfly.go
2019-05-10 19:17:14 -04:00

81 lines
1.5 KiB
Go

package pty
import (
"errors"
"os"
"strings"
"syscall"
"unsafe"
)
// same code as pty_darwin.go
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 := grantpt(p); err != nil {
return nil, nil, err
}
if err := unlockpt(p); err != nil {
return nil, nil, err
}
t, err := os.OpenFile(sname, os.O_RDWR, 0)
if err != nil {
return nil, nil, err
}
return p, t, nil
}
func grantpt(f *os.File) error {
_, err := isptmaster(f.Fd())
return err
}
func unlockpt(f *os.File) error {
_, err := isptmaster(f.Fd())
return err
}
func isptmaster(fd uintptr) (bool, error) {
err := ioctl(fd, syscall.TIOCISPTMASTER, 0)
return err == nil, err
}
var (
emptyFiodgnameArg fiodgnameArg
ioctl_FIODNAME = _IOW('f', 120, unsafe.Sizeof(emptyFiodgnameArg))
)
func ptsname(f *os.File) (string, error) {
name := make([]byte, _C_SPECNAMELEN)
fa := fiodgnameArg{Name: (*byte)(unsafe.Pointer(&name[0])), Len: _C_SPECNAMELEN, Pad_cgo_0: [4]byte{0, 0, 0, 0}}
err := ioctl(f.Fd(), ioctl_FIODNAME, uintptr(unsafe.Pointer(&fa)))
if err != nil {
return "", err
}
for i, c := range name {
if c == 0 {
s := "/dev/" + string(name[:i])
return strings.Replace(s, "ptm", "pts", -1), nil
}
}
return "", errors.New("TIOCPTYGNAME string not NUL-terminated")
}