Get list of ethernet devices

[Michael Ross]

Moin,

I'm setting up a system on an external USB drive,
serving as fallback in case of a server failure:

Customer takes USB drive, plugs it into any of his PCs and boots of it.

Now I am looking for a good method to configure the network:

I could just start dhclient on any NIC which could possibly be there,
thus cramming rc.conf with
	ifconfig_em0="DHCP"
	ifconfig_em1="DHCP"
	ifconfig_fxp0="DHCP"
and so on.

Or I could grep ifconfig or dmesg output for ethernet interfaces and  
dhclient these.

Both sound like a very messy solution.

So I would step beyond my current area of expertise, grep some source from  
sysinstall, bsdinstall or somewhere and do it in C.
But I'm kind of hoping anybody can point me to a readymade solution yet  
unknown to me.


Regards,

Michael