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

Since the OP's example refers to Bash, here's a way to extract fields such as HWaddr without the use of additional tools:

x=$(ifconfig eth0) && x=${x#*HWaddr } && echo ${x%% *}

In the 1st step this assigns the ouput of ifconfig to x. The 2nd step removes everything before "HWaddr ". In the final step everything after " " (the space behind the MAC) is removed.

Reference: http://www.gnu.org/software/bash/manual/bashref.html#Shell-Parameter-Expansion

Answer 2

Nice and quick one:

ifconfig eth0 | grep HWaddr | cut -d ' ' -f 11

Answer 3

ifconfig en0 | grep ether - for wired mac address

ifconfig en1 | grep ether - for wireless mac address

Answer 4

Not sure whether there really are any advantages, but you can simply use awk:

ifconfig eth0 | awk '/HWaddr/ {print $5}'

Answer 5

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

Answer 6

Use:

ifconfig eth0 | grep HWaddr

or

ifconfig eth0 |grep HWaddr

This will pull just the MAC address and nothing else.

You can change your MAC address to whatever you want:

ifconfig eth0 down,
ifconfig eth0 hw ether (new MAC address),
ifconfig eth0 up