System-wide SOCKS Proxy Settings?

If I have a SOCKS proxy running on a specific port, is there a way to configure all network traffic to leave through it? If I configure the SOCKS proxy in the Network system preference, it seems to work properly for all browsers without additional configuration. (As reported by a quick Google for 'what is my IP' in both Chrome and Safari.) However, a traceroute does not seem to be using this proxy, nor do downloads using curl. I also have no way of knowing whether other apps like Mail (SMTP) or an SSH connection are using the proxy. I found the app MacProxy, but it's only a 30-day trial. It seems like there is surely a way to configure this via the command line for free?