Tor needs to parse its command line exactly once
$ /usr/sbin/tor --ControlPortWriteToFile -f --ControlPort auto
Dec 04 16:16:22.230 [notice] Tor v0.2.3.8-alpha (git-da15c0cbd6638af3). This is experimental software. Do not rely on it for strong anonymity. (Running on Linux x86_64)
Dec 04 16:16:22.232 [warn] Unable to open configuration file "--ControlPort".
Dec 04 16:16:22.232 [err] Reading config failed--see warnings above.