egrep Regex
'([0-9a-f]{2}:){5}[0-9a-f]{2}'
Example
for i in $(virsh list |grep -v Name|awk '{print $2}' ) ; do
echo -e $i
virsh domiflist $i
done | egrep '([0-9a-f]{2}:){5}[0-9a-f]{2}' | awk '{print $NF}'
'([0-9a-f]{2}:){5}[0-9a-f]{2}'
for i in $(virsh list |grep -v Name|awk '{print $2}' ) ; do
echo -e $i
virsh domiflist $i
done | egrep '([0-9a-f]{2}:){5}[0-9a-f]{2}' | awk '{print $NF}'