In article <20030518090038.780d7d26.jklowden@schemamania.org> you write:
>Is there a portable way to learn the Ethernet address of a device?  
>
>I see the kernel spit it out at configuration time.  I don't know any
>other way to display it.  

You can always use ifconfig:

fastnet:~$ ifconfig ne0
ne0: flags=8863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        address: 00:00:a4:10:7a:97
        media: Ethernet 10baseT
        status: active
        inet 172.17.11.29 netmask 0xffffff00 broadcast 172.17.11.255

The first address listed there is the MAC address for Ethernet devices.

>One of my compatriots wrote an ioctl query for Linux that uses flags (e.g.
>SIOCGIFHWADDR) that we don't support, leading me to wonder if there wasn't
>a higher level interface.  

I _think_ that getifaddrs() should return it as an AF_LINK address, along
with all the other addresses for each interface.  Alternatively, it looks
like SIOCGIFADDR might do what you want, at least if you call it on a
PF_LINK socket.  See networking(4) for (too few) details.

-- 
Ben Harris