mirror of https://github.com/docker/cli.git
66 lines
1.2 KiB
Go
66 lines
1.2 KiB
Go
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package pty
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import (
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"errors"
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"os"
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"syscall"
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"unsafe"
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)
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func open() (pty, tty *os.File, err error) {
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pFD, err := syscall.Open("/dev/ptmx", syscall.O_RDWR|syscall.O_CLOEXEC, 0)
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if err != nil {
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return nil, nil, err
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}
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p := os.NewFile(uintptr(pFD), "/dev/ptmx")
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// In case of error after this point, make sure we close the ptmx fd.
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defer func() {
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if err != nil {
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_ = p.Close() // Best effort.
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}
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}()
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sname, err := ptsname(p)
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if err != nil {
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return nil, nil, err
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}
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if err := grantpt(p); err != nil {
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return nil, nil, err
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}
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if err := unlockpt(p); err != nil {
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return nil, nil, err
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}
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t, err := os.OpenFile(sname, os.O_RDWR, 0)
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if err != nil {
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return nil, nil, err
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}
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return p, t, nil
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}
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func ptsname(f *os.File) (string, error) {
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n := make([]byte, _IOC_PARM_LEN(syscall.TIOCPTYGNAME))
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err := ioctl(f.Fd(), syscall.TIOCPTYGNAME, uintptr(unsafe.Pointer(&n[0])))
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if err != nil {
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return "", err
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}
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for i, c := range n {
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if c == 0 {
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return string(n[:i]), nil
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}
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}
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return "", errors.New("TIOCPTYGNAME string not NUL-terminated")
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}
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func grantpt(f *os.File) error {
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return ioctl(f.Fd(), syscall.TIOCPTYGRANT, 0)
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}
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func unlockpt(f *os.File) error {
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return ioctl(f.Fd(), syscall.TIOCPTYUNLK, 0)
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}
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