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 encap:Ethernet  HWaddr 1F:2E:19:10:3B:52    
          inet addr:127.0.0.66  Bcast:127.255.255.255  Mask:255.0.0.0    
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          ....
          ....

Should I use cut, AWK or anything else, and what are the merits and demerits of one method over the other.

@Nabin: the "HWaddr" field. – Peter Mortensen Nov 22 '14 at 16:33 — Peter Mortensen, Nov 22 '14 at 16:33

Michalis · Answer 1 · 2014-05-20T23:40:09.940

118

You can do a cat under /sys/class/

cat /sys/class/net/*/address

Specifically for eth0

cat /sys/class/net/eth0/address

edited May 20 '14 at 23:40

answered Jun 13 '11 at 17:53

Michalis

1,508
1
10
10

1

This gives all addresses, not just for eth0, for example. – MickeyfAgain_BeforeExitOfSO May 08 '14 at 15:56
Iin openwrt cat /sys/class/net/eth0/address works a treat: "cat /sys/class/net/eth0/address" gives "c2:ee:1e:08:e6:39" Note eth0 links you to the hardware specific location:"cd /sys/class/net/eth0/" changes the cwd to "/sys/devices/platform/ag71xx.0/net/eth0/" – NULL pointer Jul 09 '15 at 09:23
1

To store in a variable: `MacAdd=\`cat /sys/class/net/eth0/address\``. – haccks Aug 18 '16 at 07:43

Robert Gamble · Answer 2 · 2008-10-29T12:18:05.357

74

I would use:

ifconfig eth0 | grep -o -E '([[:xdigit:]]{1,2}:){5}[[:xdigit:]]{1,2}'

The -o will cause grep to only print the part of the line that matches the expression. [[:xdigit:]]{1,2} will match 1 or 2 hexidecimal digits (Solaris doesn't output leading zeros).

edited Oct 29 '08 at 12:18

answered Oct 29 '08 at 05:56

Robert Gamble

106,424
25
145
137

1

What? This will match regardless of placement of the MAC address whereas the other solutions will not. – Robert Gamble Oct 29 '08 at 06:04
It does have the advantage of also working on OSX since that ifconfig use 'ether' instead of 'HWaddr' – albertb Oct 29 '08 at 06:07
That was my intention, I have worked with plenty of different Unixes and this is the only solution that will work on all of them. – Robert Gamble Oct 29 '08 at 06:10
I don't understand the downvote, my original thought was that it's over-engineered for the job but it works and is better on slightly different output (I'd want to put it in a script so I don't have to remember the regex). – paxdiablo Oct 29 '08 at 06:51
3

That 'grep -o' is a handy addition to my knowledge as well. – paxdiablo Oct 29 '08 at 06:53
Are there any UNICES that don't output leading zeros for the MAC sections (necessitating "{1,2}" instead of "{2}")? – paxdiablo Oct 29 '08 at 06:57
This is the best way I've seen. That's because this command will be useful not only with ifconfig but with any other source of MAC as could be extracting the MACS of Xen DomU with xm network-list the MACS of the ARP caché, etc – Álvaro Mar 12 '12 at 09:04
1

I have used `ifconfig eth0 | grep -Eo '([[:xdigit:]]{1,2}[:-]){5}[[:xdigit:]]{1,2}' | head -n1` to compensate for devices that contain '-' instead of ':' and/or report more than 6 bytes. – Darcara Sep 29 '13 at 20:09

score 25 · Answer 3 · answered Oct 29 '08 at 11:58

I like using /sbin/ip for these kind of tasks, because it is far easier to parse:

$ ip link show eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:0c:29:30:21:48 brd ff:ff:ff:ff:ff:ff

You can trivially get the mac address from this output with awk:

$ ip link show eth0 | awk '/ether/ {print $2}'
00:0c:29:30:21:48

If you want to put a little more effort in, and parse more data out, I recommend using the -online argument to the ip command, which will let you treat every line as a new device:

$ ip -o link 
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue \    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000\    link/ether 00:0c:29:30:21:48 brd ff:ff:ff:ff:ff:ff
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000\    link/ether 00:0c:29:30:21:52 brd ff:ff:ff:ff:ff:ff
4: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 100\    link/[65534] 
5: sit0: <NOARP> mtu 1480 qdisc noop \    link/sit 0.0.0.0 brd 0.0.0.0

Not all distros ship `/sbin/ip`, which belongs to the `iproute2` package. But this is the best solution: ip is much nicer than ifconfig! — ephemient, Oct 29 '08 at 14:30

score 10 · Answer 4 · answered Oct 29 '08 at 05:55

10

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

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

answered Oct 29 '08 at 05:55

albertb

2,874
1
20
16

Use `ip addr` instead of ifconfig. `ip addr | grep -C1 "link/ether"` should do. – nPcomp Dec 29 '16 at 19:12

xebeche · Answer 5 · 2011-02-17T19:15:50.827

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

nPcomp · Answer 6 · 2019-08-01T12:10:18.857

3

For Ubuntu/Debian

ifconfig | grep HW | awk '{print $5}'

For Rhat or CentOs try

ip add | grep link/ether | awk '{print $2}'

edited Aug 01 '19 at 12:10

answered Jun 02 '16 at 00:25

nPcomp

8,637
2
54
49

score 2 · Answer 7 · answered Sep 28 '11 at 13:16

I prefer the method described here (with slight modification): http://www.askdavetaylor.com/how_do_i_figure_out_my_ip_address_on_a_mac.html

ifconfig | grep "inet " | grep -v 127.0.0.1 | cut -d " " -f2

Which you can then alias to a short 'myip' command for future use:

echo "alias myip=\"ifconfig | grep 'inet ' | grep -v 127.0.0.1 | cut -d ' ' -f2\"" >> ~/.bash_profile

score 1 · Answer 8 · answered Sep 30 '14 at 13:57

1

On Ubuntu 14.04 in terminal

ifconfig | grep HW

answered Sep 30 '14 at 13:57

Fernando_Jr

430
5
10

score 1 · Answer 9 · edited Oct 27 '15 at 11:26

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`

edited Oct 27 '15 at 11:26

kenorb

155,785
88
678
743

answered May 11 '11 at 04:14

phoxis

60,131
14
81
117

score 1 · Answer 10 · edited Sep 15 '20 at 20:24

1

ifconfig en1 | grep -o -E '([[:xdigit:]]{1,2}:){5}[[:xdigit:]]{1,2}'

Replace "en1" with the name of the nic card "eth0" or remove altogether "en1" - easy and useful solution.

edited Sep 15 '20 at 20:24

Sergio Rodriguez

8,258
3
18
25

answered Sep 15 '20 at 10:59

Tarun Bansal

21
1

Kyle Clegg · Answer 11 · 2012-09-07T15:48:25.113

0

Note: on OS X eth0 may not work. Use p2p0:

ifconfig p2p0 | grep -o -E '([[:xdigit:]]{1,2}:){5}[[:xdigit:]]{1,2}'

edited Sep 07 '12 at 15:48

answered Aug 29 '12 at 14:44

Kyle Clegg

38,547
26
130
141

interface on my mac server is en0 , so p2p0 doesn't work always – Dukeatcoding Sep 07 '12 at 09:43

score 0 · Answer 12 · edited Nov 22 '14 at 16:37

0

This works for me on Mac OS X:

ifconfig en0 | grep -Eo ..\(\:..\){5}

So does:

ifconfig en0 | grep -o -E '([[:xdigit:]]{1,2}:){5}[[:xdigit:]]{1,2}'

Both are variations of examples above.

edited Nov 22 '14 at 16:37

Peter Mortensen

30,738
21
105
131

answered Mar 06 '13 at 03:05

CRGreen

3,406
1
14
24

score 0 · Answer 13 · edited Oct 27 '15 at 10:06

0

ifconfig | grep -i hwaddr | cut -d ' ' -f11

edited Oct 27 '15 at 10:06

whoan

8,143
4
39
48

answered Nov 09 '13 at 10:29

Ashwin Lakshmanan

149
2
5

score 0 · Answer 14 · edited Oct 27 '15 at 09:59

0

Nice and quick one:

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

edited Oct 27 '15 at 09:59

kenorb

155,785
88
678
743

answered Mar 27 '15 at 10:15

Hugh

193
1
1
11

score 0 · Answer 15 · answered May 09 '16 at 21:19

0

I needed to get MAC address of the active adapter, so ended up using this command.

ifconfig -a | awk '/^[a-z]/ { iface=$1; mac=$NF; next } /inet addr:/ { print mac }' | grep -o -E '([[:xdigit:]]{1,2}:){5}[[:xdigit:]]{1,2}'

Hope it helps.

answered May 09 '16 at 21:19

Dogukan

111
2

score 0 · Answer 16 · answered Sep 19 '18 at 08:56

0

ifconfig en0 | grep ether - for wired mac address

ifconfig en1 | grep ether - for wireless mac address

answered Sep 19 '18 at 08:56

Sateesh Pasala

772
8
15

score 0 · Answer 17 · edited Aug 27 '19 at 22:14

0

this worked for me

ifconfig eth0 | grep -o -E ..:..:..:..:..:..

instead of eth0 you can write the interface you need it's mac address

edited Aug 27 '19 at 22:14

Jason

2,493
2
27
27

answered Aug 27 '19 at 19:51

Adel Skn

1
4

score -1 · Answer 18 · edited Nov 22 '14 at 16:39

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

score -1 · Answer 19 · edited Nov 22 '14 at 16:40

-1

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

edited Nov 22 '14 at 16:40

Peter Mortensen

30,738
21
105
131

answered Jun 17 '14 at 12:04

yankeevader

1

HW, HWaddr is not an option for some Linux/Unix systems, and it will show nothing. – amrx May 05 '16 at 06:21

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

19 Answers19

Linked