TUN-3201: Create base cloudflared UI structure

vendor/github.com/gdamore/tcell/tscreen_linux.go

@@ -0,0 +1,119 @@
+// +build linux
+
+// Copyright 2019 The TCell Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use file except in compliance with the License.
+// You may obtain a copy of the license at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tcell
+
+import (
+	"os"
+	"os/signal"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+type termiosPrivate struct {
+	tio *unix.Termios
+}
+
+func (t *tScreen) termioInit() error {
+	var e error
+	var raw *unix.Termios
+	var tio *unix.Termios
+
+	if t.in, e = os.OpenFile("/dev/tty", os.O_RDONLY, 0); e != nil {
+		goto failed
+	}
+	if t.out, e = os.OpenFile("/dev/tty", os.O_WRONLY, 0); e != nil {
+		goto failed
+	}
+
+	tio, e = unix.IoctlGetTermios(int(t.out.Fd()), unix.TCGETS)
+	if e != nil {
+		goto failed
+	}
+
+	t.tiosp = &termiosPrivate{tio: tio}
+
+	// make a local copy, to make it raw
+	raw = &unix.Termios{
+		Cflag: tio.Cflag,
+		Oflag: tio.Oflag,
+		Iflag: tio.Iflag,
+		Lflag: tio.Lflag,
+		Cc:    tio.Cc,
+	}
+	raw.Iflag &^= (unix.IGNBRK | unix.BRKINT | unix.PARMRK | unix.ISTRIP |
+		unix.INLCR | unix.IGNCR | unix.ICRNL | unix.IXON)
+	raw.Oflag &^= unix.OPOST
+	raw.Lflag &^= (unix.ECHO | unix.ECHONL | unix.ICANON | unix.ISIG |
+		unix.IEXTEN)
+	raw.Cflag &^= (unix.CSIZE | unix.PARENB)
+	raw.Cflag |= unix.CS8
+
+	// This is setup for blocking reads.  In the past we attempted to
+	// use non-blocking reads, but now a separate input loop and timer
+	// copes with the problems we had on some systems (BSD/Darwin)
+	// where close hung forever.
+	raw.Cc[unix.VMIN] = 1
+	raw.Cc[unix.VTIME] = 0
+
+	e = unix.IoctlSetTermios(int(t.out.Fd()), unix.TCSETS, raw)
+	if e != nil {
+		goto failed
+	}
+
+	signal.Notify(t.sigwinch, syscall.SIGWINCH)
+
+	if w, h, e := t.getWinSize(); e == nil && w != 0 && h != 0 {
+		t.cells.Resize(w, h)
+	}
+
+	return nil
+
+failed:
+	if t.in != nil {
+		t.in.Close()
+	}
+	if t.out != nil {
+		t.out.Close()
+	}
+	return e
+}
+
+func (t *tScreen) termioFini() {
+
+	signal.Stop(t.sigwinch)
+
+	<-t.indoneq
+
+	if t.out != nil && t.tiosp != nil {
+		unix.IoctlSetTermios(int(t.out.Fd()), unix.TCSETSF, t.tiosp.tio)
+		t.out.Close()
+	}
+
+	if t.in != nil {
+		t.in.Close()
+	}
+}
+
+func (t *tScreen) getWinSize() (int, int, error) {
+
+	wsz, err := unix.IoctlGetWinsize(int(t.out.Fd()), unix.TIOCGWINSZ)
+	if err != nil {
+		return -1, -1, err
+	}
+	return int(wsz.Col), int(wsz.Row), nil
+}