vendor: add github.com/mattn/go-colorable

vendor/github.com/mattn/go-isatty/isatty_windows.go

@@ -0,0 +1,94 @@
+// +build windows
+// +build !appengine
+
+package isatty
+
+import (
+	"strings"
+	"syscall"
+	"unicode/utf16"
+	"unsafe"
+)
+
+const (
+	fileNameInfo uintptr = 2
+	fileTypePipe         = 3
+)
+
+var (
+	kernel32                         = syscall.NewLazyDLL("kernel32.dll")
+	procGetConsoleMode               = kernel32.NewProc("GetConsoleMode")
+	procGetFileInformationByHandleEx = kernel32.NewProc("GetFileInformationByHandleEx")
+	procGetFileType                  = kernel32.NewProc("GetFileType")
+)
+
+func init() {
+	// Check if GetFileInformationByHandleEx is available.
+	if procGetFileInformationByHandleEx.Find() != nil {
+		procGetFileInformationByHandleEx = nil
+	}
+}
+
+// IsTerminal return true if the file descriptor is terminal.
+func IsTerminal(fd uintptr) bool {
+	var st uint32
+	r, _, e := syscall.Syscall(procGetConsoleMode.Addr(), 2, fd, uintptr(unsafe.Pointer(&st)), 0)
+	return r != 0 && e == 0
+}
+
+// Check pipe name is used for cygwin/msys2 pty.
+// Cygwin/MSYS2 PTY has a name like:
+//   \{cygwin,msys}-XXXXXXXXXXXXXXXX-ptyN-{from,to}-master
+func isCygwinPipeName(name string) bool {
+	token := strings.Split(name, "-")
+	if len(token) < 5 {
+		return false
+	}
+
+	if token[0] != `\msys` && token[0] != `\cygwin` {
+		return false
+	}
+
+	if token[1] == "" {
+		return false
+	}
+
+	if !strings.HasPrefix(token[2], "pty") {
+		return false
+	}
+
+	if token[3] != `from` && token[3] != `to` {
+		return false
+	}
+
+	if token[4] != "master" {
+		return false
+	}
+
+	return true
+}
+
+// IsCygwinTerminal() return true if the file descriptor is a cygwin or msys2
+// terminal.
+func IsCygwinTerminal(fd uintptr) bool {
+	if procGetFileInformationByHandleEx == nil {
+		return false
+	}
+
+	// Cygwin/msys's pty is a pipe.
+	ft, _, e := syscall.Syscall(procGetFileType.Addr(), 1, fd, 0, 0)
+	if ft != fileTypePipe || e != 0 {
+		return false
+	}
+
+	var buf [2 + syscall.MAX_PATH]uint16
+	r, _, e := syscall.Syscall6(procGetFileInformationByHandleEx.Addr(),
+		4, fd, fileNameInfo, uintptr(unsafe.Pointer(&buf)),
+		uintptr(len(buf)*2), 0, 0)
+	if r == 0 || e != 0 {
+		return false
+	}
+
+	l := *(*uint32)(unsafe.Pointer(&buf))
+	return isCygwinPipeName(string(utf16.Decode(buf[2 : 2+l/2])))
+}