Best way to extract MAC address from ifconfig's output?

Question

What is the best way to extract the MAC address from ifconfig\'s output?

Sample output:

bash-3.00# ifconfig eth0        
eth0      Link          


        

Answer 1

How about this one:

ifconfig eth0 | grep -Eo ..\(\:..\){5}

or more specifically

ifconfig eth0 | grep -Eo [:0-9A-F:]{2}\(\:[:0-9A-F:]{2}\){5}

and also a simple one

ifconfig eth0 | head -n1 | tr -s ' ' | cut -d' ' -f5`