Function startPty

pty/start_windows.go:20–136

Allocates a PTY and starts the specified command attached to it. See: https://docs.microsoft.com/en-us/windows/console/creating-a-pseudoconsole-session#creating-the-hosted-process

(cmd *Cmd, opt ...StartOption)

// Allocates a PTY and starts the specified command attached to it.
// See: https://docs.microsoft.com/en-us/windows/console/creating-a-pseudoconsole-session#creating-the-hosted-process
func startPty(cmd *Cmd, opt ...StartOption) (_ PTYCmd, _ Process, retErr error) {
	var opts startOptions
	for _, o := range opt {
		o(&opts)
	}

	fullPath, err := exec.LookPath(cmd.Path)
	if err != nil {
		return nil, nil, err
	}
	pathPtr, err := windows.UTF16PtrFromString(fullPath)
	if err != nil {
		return nil, nil, err
	}
	argsPtr, err := windows.UTF16PtrFromString(windows.ComposeCommandLine(cmd.Args))
	if err != nil {
		return nil, nil, err
	}
	if cmd.Dir == "" {
		cmd.Dir, err = os.Getwd()
		if err != nil {
			return nil, nil, err
		}
	}
	dirPtr, err := windows.UTF16PtrFromString(cmd.Dir)
	if err != nil {
		return nil, nil, err
	}

	winPty, err := newConPty(opts.ptyOpts...)
	if err != nil {
		return nil, nil, err
	}
	defer func() {
		if retErr != nil {
			// we hit some error finishing setup; close pty, so
			// we don't leak the kernel resources associated with it
			_ = winPty.Close()
		}
	}()
	if winPty.opts.sshReq != nil {
		cmd.Env = append(cmd.Env, fmt.Sprintf("SSH_TTY=%s", winPty.Name()))
	}

	attrs, err := windows.NewProcThreadAttributeList(1)
	if err != nil {
		return nil, nil, err
	}
	// Taken from: https://github.com/microsoft/hcsshim/blob/2314362e977aa03b3ed245a4beb12d00422af0e2/internal/winapi/process.go#L6
	err = attrs.Update(0x20016, unsafe.Pointer(winPty.console), unsafe.Sizeof(winPty.console))
	if err != nil {
		return nil, nil, err
	}

	startupInfo := &windows.StartupInfoEx{}
	startupInfo.ProcThreadAttributeList = attrs.List()
	startupInfo.StartupInfo.Flags = windows.STARTF_USESTDHANDLES
	startupInfo.StartupInfo.Cb = uint32(unsafe.Sizeof(*startupInfo))