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

Output of ifconfig:

$ifconfig

eth0      Link encap:Ethernet  HWaddr 00:1b:fc:72:84:12
      inet addr:172.16.1.13  Bcast:172.16.1.255  Mask:255.255.255.0
      inet6 addr: fe80::21b:fcff:fe72:8412/64 Scope:Link
      UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
      RX packets:638661 errors:0 dropped:20 overruns:0 frame:0
      TX packets:93858 errors:0 dropped:0 overruns:0 carrier:2
      collisions:0 txqueuelen:1000
      RX bytes:101655955 (101.6 MB)  TX bytes:42802760 (42.8 MB)
      Memory:dffc0000-e0000000

lo        Link encap:Local Loopback
      inet addr:127.0.0.1  Mask:255.0.0.0
      inet6 addr: ::1/128 Scope:Host
      UP LOOPBACK RUNNING  MTU:16436  Metric:1
      RX packets:3796 errors:0 dropped:0 overruns:0 frame:0
      TX packets:3796 errors:0 dropped:0 overruns:0 carrier:0
      collisions:0 txqueuelen:0
      RX bytes:517624 (517.6 KB)  TX bytes:517624 (517.6 KB)

The best way to extract MAC address is:

ifconfig | sed '1,1!d' | sed 's/.*HWaddr //' | sed 's/\ .*//' | sed -e 's/:/-/g' > mac_address