Finding the Public IP address in a shell script

Question

I can find my IP address using ifconfig or hostname -i command.

But how do I find my Public IP?

(I have a static public IP but I want to find it out using unix command)

Answer 1

One way: http://www.whatismyip.com/

Answer 2

You can request myip.opendns.com. from OpenDNS. dig @208.67.222.220 myip.opendns.com

Answer 3

If

1. you only have one public IP address and
2. you are directly connected to the internet (no NAT / proxy / VPN etc)

then you can just parse the output from ifconfig for the IP addresses of the interfaces (the "inet addr:" part) to get the list of IP addresses of all your interfaces. The one IP address that is not in the private range (see http://en.wikipedia.org/wiki/IP%5Faddress#IPv4%5Fprivate%5Faddresses ) is your public IP address.

The same list can also be obtained through

ip addr show

which may be easier to parse.

If you do not have a direct internet connection (NAT etc.), there is no way to find your public IP address without external help (since your computer does not know it). Then you'll have to do it like in the other answers.

Answer 4

One way is , you can make a request to the page at

http://www.biranchi.com/ip.php

it returns the IP address of your system

Answer 5

A very simple anwser if you have internet access is:

curl icanhazip.com

Bear in mind, trusting third party sources for your IP might be problematic especially if what your doing with that data has special meaning.

A more trustworthy way is to pick a known, trustworthy DNS server (ideally running DNSSEC) and query the hostname of the box with it, providing your DNS server contains such entries;

dig @trustworthysource.com +short `hostname`

Answer 6

Okay...I know that this is WAY after the fact and probably not even worth posting, but here's my working solution.

#!/bin/sh

IP="$(ifconfig | egrep 'inet ' | sed -e 's/inet //' -e 's/addr://' -e 's/ Bcast.*//' -e 's/127.*//')"
echo $IP

Nice and simple.

Answer 7

Duplicate of many other questions (hence my -1 vote).

• Discovering public IP programatically
• Obtaining Own External IP Address in POSIX C
• Trying to get NAT’s external IPAddress with INATExternalIPAddressCallback in C#
• ...

Answer 8

Google now displays your public IP address: http://www.google.com/search?q=ip

Answer 9

If what you want is to find the external ip address on your router, you either ask the router itself for its wan address, or ask someone outside to get it for you..

for a manual way you can browse any of the above given sites that will return the ip of the incomming request.

For an automated way, you can try :

wget -q -O - http://www.ipaddressworld.com | grep '[0-9]\{1,3\}\.[0-9]\{1,3\}'\. 

which will get you the line that contains the ip address on the http response, then parse it out with sed, awk , etc

Answer 10

you can use just the shell to check your external ip, also using external providers

#!/bin/bash
TCP_HOST="checkmyip.com"
TCP_PORT=80              
exec 5<>/dev/tcp/"${TCP_HOST}"/"${TCP_PORT}"
echo -e "GET / HTTP/1.0\nHOST:${TCP_HOST}\n" >&5
while read -r line 
do  
    case "$line" in
        *"Your local IP address is"* ) 
            line="${line#*Your local IP address is&nbsp;}"
            line=${line%%</p>*}
            echo "Your ip is: $line"
            exec >&5-
            exit
            ;;            
    esac
done <&5

output

Answer 11

I took a little different approach by using the STUN protocol which was designed for NAT Traversal. If you use Ubuntu you can just install the package "stun" by typing:

sudo apt-get install stun

The package installs a STUN server which you probably wont need, but it also comes with a STUN test client which I used to solve this problem. Now you can retrieve your public IP with one (not so simple) command:

stun -v stunserver.org 2>&1 1>/dev/null | grep MappedAddress | sed -e 's/.*MappedAddress = //' -e 's/:.*//' | uniq

Now, what it does is: stun contacts the public STUN server "stunserver.org" and gets an answer back with your public IP, the rest of the command is just to filter out the IP from the output.

Answer 12

A simple shell script solution can be found here:

http://bash.cyberciti.biz/misc-shell/read-local-ip-address/

Works on Linux, FreeBSD, SunOS and Apple Darwin (with a minor modification).

Answer 13

lynx --dump http://www.whatismyip.com/ | grep -o '[0-9].*\.[0-9].*\.[0-9].*\.[0-9].*'
-m1 

Answer 14

I'm doing this a lot, and from a lot of devices, so I made my own two services on a server :

1) php file on a webserver :

$ cat index.php 
<?php echo $_SERVER['REMOTE_ADDR']; echo "\n" ?>

usage on a shell:

$ echo "GET /" | nc -4 myserver.com 80
79.22.192.12

also working with ipv6:

$ echo "GET /" | nc myserver.com 80
2a01:e34:ee7d:180::3

On a router:

router#more http://myserver.com/index.php
79.22.192.12

2) quick hack with a custom telnet server: xinetd spawning /usr/bin/env:

service telnet
{
   server           = /usr/bin/env
   socket_type      = stream
   protocol         = tcp
   flags            = IPv6
   wait             = no
   port             = 23
   cps              = 3 30
   passenv          = %a
}

and then telnet to it :

$ nc -4 myserver.com 23
REMOTE_HOST=::ffff:79.22.192.12

$ nc myserver.com 23
REMOTE_HOST=2a01:e34:ee7d:180::3

works the same with a router:

router#telnet myserver.com
79.22.192.12

This way you can make it work on your internal network, if some nat or proxy is involved in the communication and you'd like to know from what IP you appear.

It doesn't require any third party service.

Answer 15

I do this. It just gives me the IP without any third-party involvement..

ip addr show | grep eth0 | grep inet | tr -s " " | cut -f3 -d " " | cut -f1 -d "/"