     // FILEPointer(aka UnsafeMutablePointer<FILE>)はCのFILE*と同じと仮定
     // fdopenで fileDescriptorから filePointerを作り、
     // FILEPointerからLocalFileOutputByteStream を作り、terminalTypeを取得
-    let fileDescriptor: Int32 = {
+    let stdOutFileDescriptor: Int32 = {
         if #available(macOS 11,*) {
             return FileDescriptor.standardOutput.rawValue as Int32
         } else {

                return false
            }
            
            // default(auto):
            if Self.env["TERM"] == "xterm-256color" {
                return true
            }
                
            do {
                if try terminalType() == .file {
                    return false
                }
                
                // TODO: pipe -> no-color
                // TODO: tty -> keep guessing
    //            if isatty()
                
                return false
            } catch {
                return false
            }
        }()
        
        self.verbose = verboseCommandLineFlag

        silence = silenceModeCommandLineFlag
        
        colored = {
            // commandline
            if noColorCommandLineFlag {
                return false
            }
