[CentOS] 6.x - find interface with link up

Thu Dec 15 21:53:01 UTC 2011
Alexander Dalloz <ad+lists at uni-x.org>

Am 15.12.2011 22:13, schrieb Les Mikesell:
> On Thu, Dec 15, 2011 at 2:56 PM,  <m.roth at 5-cent.us> wrote:
>> Les Mikesell wrote:
>>> In earlier versions 'mii-tool' would iterate over interfaces and show
>>> which have link up.   In 6.x it wants an interface as a parameter.
>>> What is the appropriate way to find which of some number of of
>>> interfaces are connected?   Better yet, what is the least typing to
>>> get the mac addresses of those interfaces?
>>
>> ethtool, or even lshw.
>>
> 
> How do you make ethtool iterate over the available interfaces?

How about following?

for i in /sys/class/net/eth*; do
  echo "${i##*/}: "
  cat $i/{carrier,address}
done

Alexander