automating network configuration

[Romain Garbage]

Hello,

I am looking for a way to automate the configuration of my network
depending on its "topology" (don't know if it's the good word) : I
would like to check the wired interface to see if a cable is plugged
in (by looking at carrier status), if so, bring up the wired
interface, if no bring up the wireless interface.
Is there a way to do this?

I was wondering if it is possible to do so by scripting rc.conf?

Thanks in advance for any advice,
Romain