Method: Main::Daemon#detach!

Defined in:
lib/main/daemon.rb

#detach!(&block) ⇒ Object 



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# File 'lib/main/daemon.rb', line 434

def detach!(&block)
# setup a pipe to relay the grandchild pid through
#
  a, b = IO.pipe

# in the parent we wait for the pid, wait on our child to avoid zombies, and
# then exit
#
  if fork
    b.close
    pid = Integer(a.read.strip)
    a.close
    block.call(pid) if block
    Process.waitall
    exit!
  end

# the child simply exits so it can be reaped - avoiding zombies.  the pipes
# are inherited in the grandchild
#
  if fork
    exit!
  end

# finally, the grandchild sends it's pid back up the pipe to the parent is
# aware of the pid
#
  a.close
  b.puts(Process.pid)
  b.close

# might as well nohup too...
#
  Process::setsid rescue nil
end