def __init__(self, reactor, proc, name, fileno, forceReadHack=False):
        """
        Initialize, specifying a Process instance to connect to.
        """
        abstract.FileDescriptor.__init__(self, reactor)
        fdesc.setNonBlocking(fileno)
        self.proc = proc
        self.name = name
        self.fd = fileno

        if not stat.S_ISFIFO(os.fstat(self.fileno()).st_mode):
            # If the fd is not a pipe, then the read hack is never
            # applicable.  This case arises when ProcessWriter is used by
            # StandardIO and stdout is redirected to a normal file.
            self.enableReadHack = False
        elif forceReadHack:
            self.enableReadHack = True
        else:
            # Detect if this fd is actually a write-only fd. If it's
            # valid to read, don't try to detect closing via read.
            # This really only means that we cannot detect a TTY's write
            # pipe being closed.
            try:
                os.read(self.fileno(), 0)
            except OSError:
                # It's a write-only pipe end, enable hack
                self.enableReadHack = True

        if self.enableReadHack:
            self.startReading()

        Initialize, specifying a Process instance to connect to.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/process.py