Printing the IP and device name only in linux

Question

I wanted to show th device name and the ip. can any one knows how i can extract this ?

ifconfig -a 

eth0      Link encap:Ethernet  HWaddr 10:60:4b:db:60:86  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

lo        Link encap:Local Loopback  
          inet addr: 1.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:1366 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1366 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:245049 (245.0 KB)  TX bytes:245049 (245.0 KB)

Related: http://superuser.com/questions/203272/list-only-the-device-names-of-all-available-network-interfaces — ChristopheD, May 10 '14 at 08:48
possible duplicate of [Bash script issue](http://stackoverflow.com/questions/3294909/bash-script-issue) — BMW, May 10 '14 at 10:13
I assume that the output in the answer is what was wanted, which is why it was accepted; and I figured that out based on responses to other answers. How would you simplify? — Ivan X, May 11 '14 at 17:04

Jotne · Answer 1 · 2014-05-10T08:36:34.870

This is by far the best way I have found to get the IP.

IP=$(ip route get 8.8.8.8 | awk '/8.8.8.8/ {print $NF}')
echo "$IP"
192.168.1.102

To get the interface

IF=$(ip route get 8.8.8.8 | awk '/8.8.8.8/ {print $5}')
echo "$IF"
eth0

The reason for this working well, is that it gives you the IP and interface.
On VPS servers interface may have name like veth0.
This solution get correct interface by asking for where to find a route to a public IP.
You may use other than 8.8.8.8 (googles dns), but for most this should be fine.

Using ifconfig will fail if you just look for eth0 and you are using eth1 etc.
It may fail if multiple interface have IP and is connected, but only one is used to get to internet.

Ivan X · Accepted Answer · 2014-05-10T12:20:56.373

2

May I propose:

ifconfig -a | tr '\n' '~' | sed 's/~~/\n/g' | \
sed 's/^\([^ ]*\) .*inet addr:\([0-9.]*\) .*$\|^\([^ ]*\) .*$/\3\1 \2/g'

Output:

eth0 10.0.41.21
eth1 
lo 127.0.0.1

Or, if you want to omit any interfaces without IP addresses:

ifconfig -a | tr '\n' '~' | sed 's/~~/\n/g' | grep 'inet addr:' | \
sed 's/^\([^ ]*\) .*inet addr:\([0-9.]*\) .*$/\1 \2/g'

Output:

eth0 10.0.41.21
lo 127.0.0.1

This works by converting all the line breaks to tildes, then converts the double line break between interfaces back into a single line break, so that each interface is on a single line. Then, for every line, it extracts just the wanted pieces of information (interface name and IP address) and replaces the entire line with them.

(Edited since being accepted to accomodate interfaces without IP addresses, per comment below.)

edited May 10 '14 at 12:20

answered May 10 '14 at 10:56

Ivan X

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@AvinashRaj What specifically do you see? Works fine for me on Debian 7.3. (Will not work on BSD or OS X because ifconfig doesn't produce \n\n between the interfaces.) – Ivan X May 10 '14 at 11:14
it produces double new line between the interfaces in ubuntu 14.04 – Avinash Raj May 10 '14 at 11:17
@CameronKerr There's no tabs at the start of the lines, but even if there were, it would still work. – Ivan X May 10 '14 at 11:20
@AvinashRaj Just copied and pasted it into Ubuntu 14.04. Displays as described. What specifically "won't work"? What do you see? – Ivan X May 10 '14 at 11:44
@AvinashRaj Ok, I see what's happening: it's working for interfaces with IP addresses, (e.g. usb0 192.168.42.235), but it's also printing out all the info for any interface that doesn't have an IP address. I'll retool. – Ivan X May 10 '14 at 12:00
@AvinashRaj I edited the answer to accomodate interfaces without IP addresses. Try again please. – Ivan X May 10 '14 at 12:22

score 0 · Answer 3 · answered May 10 '14 at 08:40

0

Your command did not work for me at all.

Just because the IP address is NOT on the same line as device name - it will not be easy. You will need to combine some additional commands or may be write a little script.

to see only ip addresses you can use this :

ifconfig -a | grep "inet add" | awk -F ":" {'print $2'} | awk {'print $1'}

check if you have "nm-tool" installed on you linux machine and figure it out how to use this command with additional sed and awk tools to find out what you need.

answered May 10 '14 at 08:40

Max

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Hi I wanted to print the device name as well with the ip – user3622845 May 10 '14 at 09:00
if you have only one interface use this: ifconfig | grep eth0 | awk {'print $1'} ; ifconfig | awk "NR==2"| awk -F ":" {'print $2'} | awk {'print $1'} – Max May 10 '14 at 09:15
Hope it will help you – Max May 10 '14 at 09:16
ifconfig -a | sed 's/[ \t].*//;/^$/d' this command works for me.but this showing only the device name.I wanted print the all ip of devices as well. – user3622845 May 10 '14 at 09:20

score 0 · Answer 4 · answered May 10 '14 at 10:00

Please try this: Please save it as somefile.py and run it by python somefile.py

import commands

output=commands.getoutput('ifconfig')
count=0
for line in output.split("\n"):
        count+=1
        if  str("eth") in line:
                devicename = line.split()[0]
                lineipadd =  output.split("\n")[count]
                ipaddress = lineipadd.split(":")[2].split()[0]
                print devicename , ipaddress

Printing the IP and device name only in linux

4 Answers4