Which terminal command to get just IP address and nothing else?

Question

I'm trying to use just the IP address (inet) as a parameter in a script I wrote.

Is there an easy way in a unix terminal to get just the IP address, rather than looking through ifconfig?

Vidal

Yeah, or any other unique identifier about the machine I suppose. – Vidal

you get a invalid option on hostname -i? – Blown

Yeah, on Mac OS X Lion. But turns out I'm going to be doing it on Ubuntu, where it works. Thanks! – Vidal

hostname is not as reliable as ifconfig – Atlee

joel is right, specially you where talking about MAC OS and then Ubuntu – Venality

When browsing through the answers below, keep in mind that the output of ip -o address is much easier to work with than the output of ip address. – Theme

@joel, ifconfig is nothing even a little bit like reliable: the Linux implementation has been outright unmaintained for something like 15 years now; there are major new network stack features it knows nothing about. If you want full output on systems using modern network stack features, the iproute2 suite is the only tool at full parity with the features of the kernel. (As a concrete example, ifconfig only outputs numbered IP aliases and not named ones, because the latter didn't exist back when it was written). – Inhere

Answer 1

You can write a script that only return the IP like:

/sbin/ifconfig eth0 | grep 'inet addr' | cut -d: -f2 | awk '{print $1}'

For MAC:

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

Or for linux system

hostname -i | awk '{print $3}' # Ubuntu 

hostname -i # Debian

Electromotor

hostname -i on mine it returns: ::1 127.0.1.1 192.168.1.100 – Electromotor

On Debian I got just one ip. So using hostname isn't portable. – Horseweed

It says that -i and -I are both illegal options – Vidal

The hostname command doesn't work on Mountain Lion for this task. The man page says the only flags it accepts are [-fs] which frankly aren't helpful here... – Spivey

In summary: the first method depends on the adapter, which is not always the same. The second one, for me, shows two IP addresses, and the last two don't work on Mac. – Spivey

how do you store that output in a variable? – Microeconomics

@Microeconomics cyberciti.biz/faq/… – Electromotor

cut -d/ works for me(forward slash). not the back slash one – Henrik

ifconfig is deprecated and unreliable here, e.g. the grep fails on debian 9 (stretch) because it no longer outputs "inet addr: 172.17.0.4", it only outputs "inet 172.17.0.4". Use "ip" instead as described in https://mcmap.net/q/134524/-which-terminal-command-to-get-just-ip-address-and-nothing-else. – Gawlas

I must use adr instead of addr. – Chloris

@BookOfZeus I mean /sbin/ifconfig eth0 | grep 'inet adr' | cut -d: -f2 | awk '{print $1}' instead of /sbin/ifconfig eth0 | grep 'inet addr' | cut -d: -f2 | awk '{print $1}'. – Chloris

/sbin/ifconfig eth0 | grep 'inet ' | cut -d: -f2 | awk '{print $2}' – Kary

If you read man hostname you'll see that nowadays you're supposed to say hostname --all-ip-addresses on Linux. That will print all IP addresses you have separated by spaces. If you don't run multiple NICs or virtual network you will get only one IP number. – Cassandry

@MikkoRantalainen $ hostname --all-ip-addresses | sed '1s/[^ \t]//g' |wc -c result: 10 – Electromotor

@BookOfZeus Why would you want to count number of characters in the output of hostname --all-ip-addresses? – Cassandry

@MikkoRantalainen lol that counts the number of IPs ... my point is if you have multiple interfaces hostname --all-ip-addresses is not enough. So this commands output : 10.0.0.18 172.22.0.1 172.19.0.1 172.20.0.1 172.18.0.1 172.21.0.1 172.17.0.1 172.23.0.1 192.168.42.1 etc.... – Electromotor

@BookOfZeus: ok, I have one IP and your script had output 2 so it's counting off-by-one at least. Doing something like hostname --all-ip-addresses | xargs -rn1 echo | wc -l or hostname --all-ip-addresses | grep -o ' ' | wc -l should emit correct number. – Cassandry

From the entry for the -I/--all-ip-addresses option in the hostname(1) manpage: Do not make any assumptions about the order of the output. – Berryman

Answer 2

This will give you all IPv4 interfaces, including the loopback 127.0.0.1:

ip -4 addr | grep -oP '(?<=inet\s)\d+(\.\d+){3}'

This will only show eth0:

ip -4 addr show eth0 | grep -oP '(?<=inet\s)\d+(\.\d+){3}'

And this way you can get IPv6 addresses:

ip -6 addr | grep -oP '(?<=inet6\s)[\da-f:]+'

Only eth0 IPv6:

ip -6 addr show eth0 | grep -oP '(?<=inet6\s)[\da-f:]+'

Sextuplicate

The grep -oP fails on busybox v1.24.1: invalid option -- P – Limbate

grep is not installed on just about every docker conatiner for prod. So although these are all good commands, they won't be useful on containers :-( – Lithology

Best answer for my particular case. You need -P switch for Perl regular expressions or otherwise we can't use the lookbehind (?<=inet\s) token. You can get a similar result by running grep -oe 'inet [0-9\.]\+' or grep -oe 'inet6 [0-9a-f:]\+' but this way I can't get rid of the first word. In SuSE man grep reports that -P flag is experimental. – Jallier

This is the best answer. ifconfig is deprecated several years now on most os's. – Superpose

A shorter version of the second command: ip -4 a show eth0 | grep -Po 'inet \K[0-9.]*' – Prominent

You can get rid of regexp when using -br (brief) switch for ip command: ip -4 -br addr show eth0 | awk '{print $3}' – Cholecystitis

grep with -P and ip with -br dont work everywhere (alpine) this will work everywhere though ip -4 a show eth0 | awk '/inet/ {gsub(/\/\S+$/,"",$2) ; print $2}' – Assuage

Answer 3

Generally, it is never guaranteed that a system will only have one IP address, for example, you can have both an ethernet and wlan connections, and if you have active VPN connections then you'll have yet more IP addresses.

Linux

On Linux, hostname -I will list the current IP address(es). Relying on it always returning just one IP address will most likely not work as expected under some scenarios, so a more reliable way would be converting the result to an array and then loop over the elements:

ips=($(hostname -I))

for ip in "${ips[@]}"
do
    echo $ip
done

Note: If hostname -I returns the IP both in IPv4 and IPv6 formats then you can use instead hostname -I | cut -f1 -d' ' to only show the IPv4 IP.

OSX

On OSX, if you know the interface, you could use:

~$ ipconfig getifaddr en0
# OUTPUT: 192.168.1.123

which will return just the IP address.

To detect dynamically the (first) active network interface on MacOS:

network_device=$(scutil --dns |awk -F'[()]' '$1~/if_index/ {print $2;exit;}')
ip=$(ipconfig getifaddr "$network_device")
echo $ip
### OUTPUT: 192.168.1.123 

Getting the external IP

To get the external IP you could query a text-mode service, for example curl https://ipecho.net/plain would return a plain text external IP.

An possibly faster approach is to query a known DNS server, e.g.:

dig @ns1-1.akamaitech.net ANY whoami.akamai.net +short

Emilieemiline

how to get LAN ip-address ? – Unprepared

If you want IP numbers separated by lines on Linux, you don't need for loop but can just do hostname -I | xargs -rn1 echo. – Cassandry

Answer 4

hostname -I  

This command will give you the exact IP address as you want in Ubuntu. Note the flag is uppercase.

Ruthenious

compared with the number of already existing (and high voted) answers, I don not think that this answer will add any value... – Giuliana

also on Centos hostname -I (uppercase i) – Superimposed

hostname is not as reliable as ifconfig, manpage for -I option "Do not make any assumptions about the order of the output." – Bobinette

Answer 5

To get only the IP address on Mac OS X you can type the following command:

ipconfig getifaddr en0

Isa

Answer 6

On latest Ubuntu versions (14.04 - 16.04), this command did the trick for me.

hostname -I | awk '{print $1}'

Wynne

From the manual page: "[...] This option enumerates all configured addresses on all network interfaces. [...] Do not make any assumptions about the order of the output". The last sentence tells you that print $1 may or may not give you the correct result. – Datnow

Bad solution as the hostname is often bound to the loopback interface, and how does this work in multihomed environments? – Assuage

Answer 7

I prefer not to use awk and such in scripts.. ip has the option to output in JSON.

If you leave out $interface then you get all of the ip addresses:

ip -json addr show $interface | \
  jq -r '.[] | .addr_info[] | select(.family == "inet") | .local'

Pagurian

I like the way the result of command in json structural format like ip command. here is another way to get the IP address similar as above bash ip -j addr show eth0 | jp "[0].addr_info[?family== 'inet'].local | [0]" – Kary

Note that this only works on newish releases. For instance, it doesn't work on CentOS 7.5 – Ramah

Debian 11 here. Thanks for the -j pointer (the more you know). My take is: ip -json -pretty -family inet addr show scope global | sed -n '/local/{s/[^0-9.]//g;p;q}'. This will print the IPv4 address of the first interface with global scope (that excludes the loopback). Another take witout sed: ip -json -pretty -family inet addr show scope global | grep -m 1 local | tr -d -c 0-9.. And finally if you can, you may want to give jq a shot, which is the non-hacky way of processing ip's output (FINALLY a tokenizer): ip -json -family inet addr show scope global | jq -r '.[0].addr_info[0].local' – Lorica

@Lorica good hint about scope global. Probably in many cases it is desirable to omit the 0 indexes in jq. Then you will get one IP address per line if there is more than one: ip -json -family inet addr show scope global | jq -r '.[].addr_info[].local' – Lockout

Answer 8

If you have limited environment, you may use this command:

ip -4 addr show dev eth0 | grep inet | tr -s " " | cut -d" " -f3 | head -n 1

Jory

Or even: ip -o -4 addr show dev eth0 | cut -d' ' -f7 | cut -d'/' -f1 – Diamond

Yes, you are right. But be careful, if eth0 has more than one IP address, this shows all of them. – Jory

bash-4.4# ip -4 addr show dev eth0 | grep inet | tr -s " " | cut -d" " -f3 | head -n 1 172.17.0.3/16 So not good with the /16 – Lithology

Adding one more to the loop: ip -4 addr show eth0 | grep inet | awk '{print $2}' | cut -d'/' -f1. For both v4 and v6: ip addr show eth0 | grep inet | awk '{print $2}' | cut -d'/' -f1 – Memoir

If the interface name is not known (or differs between platforms) but you search for the private ip address then instead of ip -4 addr show eth0 | grep inet do a: ip -4 addr show | grep 192 – Littell

This also works ip -4 address show eth0 | awk '/inet/{split($2,a,"/");print a[1];exit}' – Cellar

Answer 9

ip -4 addr show eth0 doesn't work on some machines. For example, I get this error: ip: symbol lookup error: ip: undefined symbol: bpf_program__section_name, version LIBBPF_0.2.0

This works for me:

/sbin/ifconfig eth0 | grep 'inet ' | awk '{ print $2}'

This has one less pipe than the accepted answer. In addition, my ifconfig output does not have inet addr.

To get the IPv6 address, use this:

/sbin/ifconfig eth0 | grep 'inet6 ' | awk '{ print $2}'

Bea

Answer 10

Command ifconfig is deprected and you should use ip command on Linux.

Also ip a will give you scope on the same line as IP so it's easier to use.

This command will show you your global (external) IP:

ip a | grep "scope global" | grep -Po '(?<=inet )[\d.]+'

All IPv4 (also 127.0.0.1):

ip a | grep "scope" | grep -Po '(?<=inet )[\d.]+'

All IPv6 (also ::1):

ip a | grep "scope" | grep -Po '(?<=inet6 )[\da-z:]+'

Ellon

Note that two last commands may return more than one IP. If you want IP of the default route, you have to filter more. – Cassandry

Answer 11

I wanted something simple that worked as a Bash alias. I found that hostname -I works best for me (hostname v3.15). hostname -i returns the loopback IP, for some reason, but hostname -I gives me the correct IP for wlan0, and without having to pipe output through grep or awk. A drawback is that hostname -I will output all IPs, if you have more than one.

Crumble

Answer 12

To print only the IP address of eth0, without other text:

ifconfig eth0 | grep -Po '(?<=inet addr:)[\d.]+'

To determine your primary interface (because it might not be "eth0"), use:

route | grep ^default | sed "s/.* //"

The above two lines can be combined into a single command like this:

ifconfig `route | grep ^default | sed "s/.* //"` \
  | grep -Po '(?<=inet addr:)[\d.]+'

Flycatcher

Note that ifconfig output is not stable over multiple versions. Some versions require inet addr: but some other versions only want inet . – Cassandry

Answer 13

Few answers appear to be using the newer ip command (replacement for ifconfig) so here is one that uses ip addr, grep, and awk to simply print the IPv4 address associated with the wlan0 interface:

ip addr show wlan0|grep inet|grep -v inet6|awk '{print $2}'|awk '{split($0,a,"/"); print a[1]}'

While not the most compact or fancy solution, it is (arguably) easy to understand (see explanation below) and modify for other purposes, such as getting the last 3 octets of the MAC address like this:

ip addr show wlan0|grep link/ether|awk '{print $2}'|awk '{split($0,mac,":"); print mac[4] mac[5] mac[6]}'

Explanation: ip addr show wlan0 outputs information associated with the network interface named wlan0, which should be similar to this:

4: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether dc:a6:32:04:06:ab brd ff:ff:ff:ff:ff:ff
    inet 172.18.18.1/24 brd 172.18.18.255 scope global noprefixroute wlan0
       valid_lft forever preferred_lft forever
    inet6 fe80::d340:5e4b:78e0:90f/64 scope link 
       valid_lft forever preferred_lft forever

Next grep inet filters out the lines that don't contain "inet" (IPv4 and IPv6 configuration) and grep -v inet6 filters out the remaining lines that do contain "inet6", which should result in a single line like this one:

    inet 172.18.18.1/24 brd 172.18.18.255 scope global noprefixroute wlan0

Finally, the first awk extract the "172.18.18.1/24" field and the second removes the network mask shorthand, leaving just the IPv4 address.

Also, I think it's worth mentioning that if you are scripting then there are often many richer and/or more robust tools for obtaining this information, which you might want to use instead. For example, if using Node.js there is ipaddr-linux, if using Ruby there is linux-ip-parser, etc.

See also https://unix.stackexchange.com/questions/119269/how-to-get-ip-address-using-shell-script

Concinnate

Answer 14

ip adddr, the short way

ip -4 -br addr show enp1s0 | awk -F" " '{print $3}'|cut -d'/' -f1

or shorten

ip -4 -br a s enp1s0 | awk -F" " '{print $3}'|cut -d'/' -f1

must work in most modern Linux distribution

Froemming

Answer 15

On Ubuntu( and Debian like distro)

To obtain just the local address digits, execute the following command:

hostname -I | awk '{print $1}' 

For a comprehensive picture of your network interface configuration and global IP address use:

curl -4 icanhazip.com
curl  ifconfig.co //this responds faster

To dive deeper into the mysteries of any IP address (including your own):

 whois $(curl ifconfig.co)   

Ensure you have the whois tool installed. If not, simply execute:

sudo apt-get install whois

Ufa

Answer 16

We can simply use only 2 commands ( ifconfig + awk ) to get just the IP (v4) we want like so:

On Linux, assuming to get IP address from eth0 interface, run the following command:

/sbin/ifconfig eth0 | awk '/inet addr/{print substr($2,6)}'

On OSX, assumming to get IP adddress from en0 interface, run the following command:

/sbin/ifconfig en0 | awk '/inet /{print $2}'

To know our public/external IP, add this function in ~/.bashrc

whatismyip () {
    curl -s "http://api.duckduckgo.com/?q=ip&format=json" | jq '.Answer' | grep --color=auto -oE "\b([0-9]{1,3}\.){3}[0-9]{1,3}\b"
}

Then run, whatismyip

Waterlogged

Answer 17

That would do the trick in a Mac :

ping $(ifconfig en0 | awk '$1 == "inet" {print $2}')

That resolved to ping 192.168.1.2 in my machine.

Pro tip: $(...) means run whatever is inside the parentheses in a subshell and return that as the value.

Cockcroft

Answer 18

I always wind up needing this at the most unexpected times and, without fail, wind up searching for threads like this on SO. So I wrote a simple script to get IPv4 addresses via netstat, called echoip - you can find it here. The bash for network addresses looks like this, it also gets your public address from ipecho.net:

IPV4='\d+(\.\d+){3}'
INTERFACES=`netstat -i | grep -E "$IPV4" | cut -d ' ' -f 1`
INTERFACE_IPS=`netstat -i | grep -oE "$IPV4"`

for i in "${!INTERFACES[@]}"; do
  printf "%s:\t%s\n" "${INTERFACES[$i]}" "${INTERFACE_IPS[$i]}"
done

The echoip script yields an output like this:

$ echoip
public: 26.106.59.169
en0:    10.1.10.2

Geddes

Answer 19

In man hostname there is even more easier way which automatically excluding loopback IP and showing only space separated list of all assigned to host ip addresses:

root@srv:~# hostname --all-ip-addresses
11.12.13.14 192.168.15.19 

root@srv:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
   link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
   inet 127.0.0.1/8 scope host lo
   inet6 ::1/128 scope host 
   valid_lft forever preferred_lft forever
2: venet0: <BROADCAST,POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN 
  link/void 
  inet 11.12.13.14/32 scope global venet0:0
  inet 192.168.15.19/32 scope global venet0:1

Roseannaroseanne

Answer 20

The IPv4 address for the default route:

ip address show $(ip route | grep "^default " | head -n1 | grep -Po "(?<=dev )[^ ]+") | grep -Po "(?<=inet )[^ /]+"

The IPv6 address for the default route:

ip address show $(ip route | grep "^default " | head -n1 | grep -Po "(?<=dev )[^ ]+") | grep -Po "(?<=inet6 )[^ /]+"

These only require commands ip and grep with support for -P and -o. The head -1 is required because ip route may show multiple default routes when system has complex enough network setup.

If you don't mind which IP is which, you can just do

ip route | grep -Po '(?<=src )[^ ]+'

or

hostname --all-ip-addresses

Cassandry

It's possible to replace grep -Po with sed or awk if some system exists that supports ip command but not grep -Po. The grep -Po is not defined by POSIX... but POSIX doesn't define any networking commands so you cannot do this with POSIX only tools. – Cassandry

Answer 21

the easiest way is as Mikko said

hostname --all-ip-addresses

the output

you can also do that for little more details :

ip route

the output

Deactivate

Answer 22

Use the following command:

/sbin/ifconfig $(netstat -nr | tail -1 | awk '{print $NF}') | awk -F: '/inet /{print $2}' | cut -f1 -d ' '

Tuatara

Answer 23

Here is my version, in which you can pass a list of interfaces, ordered by priority:

getIpFromInterface()
{
    interface=$1
    ifconfig ${interface}  > /dev/null 2>&1 && ifconfig ${interface} | awk -F'inet ' '{ print $2 }' | awk '{ print $1 }' | grep .
}

getCurrentIpAddress(){
    IFLIST=(${@:-${IFLIST[@]}})
    for currentInterface in ${IFLIST[@]}
    do
        IP=$(getIpFromInterface  $currentInterface)
        [[ -z "$IP" ]] && continue
    echo ${IP/*:}
    return
    done
}

IFLIST=(tap0 en1 en0)
getCurrentIpAddress $@

So if I'm connected with VPN, Wifi and ethernet, my VPN address (on interface tap0) will be returned. The script works on both linux and osx, and can take arguments if you want to override IFLIST

Note that if you want to use IPV6, you'll have to replace 'inet ' by 'inet6'.

Poisonous

Answer 24

use this one line script: ifconfig | grep "inet " | grep -v 127.0.0.1|awk 'match($0, /([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+)/) {print substr($0,RSTART,RLENGTH)}' mac & linux (tested in ubuntu) both works.

Cuyp

Nice that it works on both. Plus you can call it with ifconfig en0 or ifconfig eth1 etc if you know the interface you want :) – Brotherly

Answer 25

You can also use the following command:

ip route | grep src

NOTE: This will only work if you have connectivity to the internet.

Allineallis

If you have multiple interfaces, this emits multiple IPs. You need to figure out default route if you want IP of outgoing internet connection. – Cassandry

Answer 26

I don't see any answer with nmcli yet which is a command-line tool for controlling NetworkManager.

So here you go :)

wolf@linux:~$ nmcli device 
DEVICE  TYPE      STATE        CONNECTION 
eth1    ethernet  unavailable  --         
eth0    ethernet  unmanaged    --         
lo      loopback  unmanaged    --         
wolf@linux:~$ 

If you want to get the information from specific network interface (let say lo for this example)

wolf@linux:~$ nmcli device show lo
GENERAL.DEVICE:                         lo
GENERAL.TYPE:                           loopback
GENERAL.HWADDR:                         00:00:00:00:00:00
GENERAL.MTU:                            65536
GENERAL.STATE:                          10 (unmanaged)
GENERAL.CONNECTION:                     --
GENERAL.CON-PATH:                       --
IP4.ADDRESS[1]:                         127.0.0.1/8
IP4.GATEWAY:                            --
IP4.ROUTE[1]:                           dst = 127.0.0.0/8, nh = 0.0.0.0,>
IP4.ROUTE[2]:                           dst = 127.0.0.1/32, nh = 0.0.0.0>
IP6.ADDRESS[1]:                         ::1/128
IP6.GATEWAY:                            --
IP6.ROUTE[1]:                           dst = ::1/128, nh = ::, mt = 256
IP6.ROUTE[2]:                           dst = ::1/128, nh = ::, mt = 0, >
wolf@linux:~$ 

But since you just want to get the IP address, just send the output to grep, cut or awk.

Let's do it step by step. (Not sure what's wrong, the code sample format just didn't work for these 3 example.)

1. Get the IPv4 line

   wolf@linux:~$ nmcli device show lo | grep 4.A IP4.ADDRESS[1]: 127.0.0.1/8 wolf@linux:~$

2. Use awk to get the IP

   wolf@linux:~$ nmcli device show lo | awk '/4.A/ {print $2}' 127.0.0.1/8 wolf@linux:~$

3. Use cut to remove the CIDR notation (/8)

   wolf@linux:~$ nmcli device show lo | awk '/4.A/ {print $2}' | cut -d / -f1 127.0.0.1 wolf@linux:~$

There your answer.

Please take note that there are tons of ways to do it using the tools that I demonstrated just now.

Let's recap the commands that I used.

nmcli device show lo | grep 4.A
nmcli device show lo | awk '/4.A/ {print $2}'
nmcli device show lo | awk '/4.A/ {print $2}' | cut -d / -f1

Sample output for these 3 commands

Command 1 output

IP4.ADDRESS[1]:                         127.0.0.1/8

Command 2 output

127.0.0.1/8

Command 3 output

127.0.0.1

Garget

nmcli is a good one. It can almost be used without auxiliary tools. Please consider updating the answer with this a bit more native/elegant method: nmcli -g IP4.ADDRESS device show lo | cut -d / -f 1 – Ramah

Answer 27

yet another way to do it.

I often need to check the IP of various interfaces (e.g eth0, tunnel, etc.)

So this is how i do it:

ip -4 -br a | awk '{print $1,$3}'

output:

$ ip -4 -br a | awk '{print $1,$3}'
lo 127.0.0.1/8
eth0 192.168.0.248/24
tun0 192.168.119.1

If you do not care about the network adapter, just remove the $1 from awk command.

ip -4 -br a | awk '{print $3}'   
127.0.0.1/8
192.168.0.248/24
192.168.119.124/24

to make it easy, i just add it as an alias (remember to escape the $'s!)

$ alias me="ip -4 -br a | awk '{print \$1,\$3}'" 
                                                                                                                              
$ me                                            
lo 127.0.0.1/8
eth0 192.168.0.248/24
tun0 192.168.119.124/24

Tobacco

Answer 28

ip addr|awk '/eth0/ && /inet/ {gsub(/\/[0-9][0-9]/,""); print $2}'

shows all your ips

Madera

Answer 29

On Redhat 64bit, this solved problem for me.

ifconfig $1|sed -n 2p|awk '{ print $2 }'|awk -F : '{ print $2 }'

Cletus

or this: curl ifconfig.me – Cletus

Answer 30

#!/bin/sh
# Tested on Ubuntu 18.04 and Alpine Linux 
# List IPS of following network interfaces:
# virtual host interfaces
# PCI interfaces
# USB interfaces
# ACPI interfaces
# ETH interfaces
for NETWORK_INTERFACE in $(ls /sys/class/net -al | grep -iE "(/eth[0-9]+$|vif|pci|acpi|usb)" | sed -E "s@.* ([^ ]*) ->.*@\1@"); do 
    IPV4_ADDRESSES=$(ifconfig $NETWORK_INTERFACE | grep -iE '(inet addr[: ]+|inet[: ]+)' | sed -E "s@\s*(inet addr[: ]+|inet[: ]+)([^ ]*) .*@\2@")
    IPV6_ADDRESSES=$(ifconfig $NETWORK_INTERFACE | grep -iE '(inet6 addr[: ]+|inet6[: ]+)' | sed -E "s@\s*(inet6 addr[: ]+|inet6[: ]+)([^ ]*) .*@\2@")
    if [ -n "$IPV4_ADDRESSES" ] || [ -n "$IPV6_ADDRESSES" ]; then
        echo "NETWORK INTERFACE=$NETWORK_INTERFACE"
        for IPV4_ADDRESS in $IPV4_ADDRESSES; do 
            echo "IPV4=$IPV4_ADDRESS"
        done
        for IPV6_ADDRESS in $IPV6_ADDRESSES; do 
            echo "IPV6=$IPV6_ADDRESS"
        done
    fi
done

Sergei

Answer 31

When looking up your external IP address on a NATed host, quite a few answers suggest using HTTP based methods like ifconfig.me eg:

$ curl ifconfig.me/ip

Over the years I have seen many of these sites come and go, I find this DNS based method more robust:

$ dig +short myip.opendns.com @resolver1.opendns.com

I have this handy alias in my ~/.bashrc:

alias wip='dig +short myip.opendns.com @resolver1.opendns.com'

Secondhand

Answer 32

These two ways worked for me:

To get IP address of your interface eth0. Replace eth0 in the below example with your interface name. ifconfig eth0 | grep -w "inet" | tr -s " " | cut -f3 -d" "

Using hostname: This will give you the inet i.e. IPAddress of your etho. using -I will give you inet value of all the interfaces whereever this value is present.

hostname -i

Cuticle

Answer 33

If you don't want to use ifconfig nor regex...

ip addr | grep eth0 | grep inet | awk '{print $2}' | cut -d"/" -f1

Sputnik

Answer 34

If you mean "Linux" and portable to Embedded Linux OS:

ip route get 8.8.8.8 | head -n 1 | tr -s ' ' | cut -d ' ' -f 7

This eliminates the need to call awk, which is not installed on all embedded Linux. Awk is a bit heavy of a process just to get a field from a string.

Every Linux environment will provide tr, head, and cut. If the embedded environment is really old it may have 'ifconfig' only, but you get the picture here: get the line, remove padding, cut what you need.

Unessential

Answer 35

result only IPv4 address exclude local specific addresses: 10.x.x.x, 127.x.x.x, 172.x.x.x, 192.x.x.x:

ip -4 addr | grep -oP '(?<=inet\s)\d+(\.\d+){3}' | grep -vE '^10|^127|^172|^192'

Vassalize

Answer 36

curl ifconfig.co 

This returns only the ip address of your system.

Pursy

This requires a working internet connection and will return your publicly visible IP address, which might or might not be what you want. – Theme

If the system is connected to the internet over NAT it will only return the public address an not the address of the system's network interface. – Erective

Answer 37

I would Use Hostname -L to get just the IP to use as a variable in a script.

Durr

Perhaps you were trying to say hostname -i or hostname -I? – Theme

user@linux:~$ Hostname -L -bash: Hostname: command not found user@linux:~$ 1. Capital H is wrong 2. No such -L – Imaginative