import errno
import os


def daemonize():
    """
    Detach from the terminal and continue as a daemon.
    """
    # swiped from twisted/scripts/twistd.py
    # See http://www.erlenstar.demon.co.uk/unix/faq_toc.html#TOC16
    if os.fork():  # launch child and...
        os._exit(0)  # kill off parent
    os.setsid()
    if os.fork():  # launch child and...
        os._exit(0)  # kill off parent again.
    os.umask(0o77)
    null = os.open("/dev/null", os.O_RDWR)
    for i in range(3):
        try:
            os.dup2(null, i)
        except OSError as e:
            if e.errno != errno.EBADF:
                raise
    os.close(null)