ipv6 validation using regex

Question

#!/bin/bash
echo "enter the ip address:"
read s
if [[ $s =~ ^(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|::(ffff(:0{1,4}){0,1}:){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))$ ]]; then

        echo -e '\E[47;31m'"\033[1mIPv6 Format\033[0m" 
        echo -n "The IPv6 Address Expanded Form:"
        EXPANDED=`sipcalc $s | fgrep Expand | cut -d '-' -f 2`
        echo -e "\033[32m $EXPANDED\033[0m"
        echo -n "IPv6 address Compress Form:"
        Compress=`sipcalc $s | fgrep Comp | cut -d '-' -f 2`
        echo  -e "\033[32m$Compress\033[0m"
        echo -n "Address Type of IPv6:"
        type=`sipcalc $s | fgrep type | cut -d '-'  -f 2,3,4`
        comment=`sipcalc $s | fgrep Comment | cut -d '-' -f 2`
        echo -e "\033[32m $type$comment\033[0m"
else
        echo  -e '\E[37;44m'"\033[1mNOT VALID IPv6 address\033[0m"
fi

Hello everyone. I am trying to validate IPv6 addresses using this script. It is working well. The problem is that it's also accepting IPs like 1111:2222:3333:4444::. Could you help me to avoid this types of IPs?

https://stackoverflow.com/questions/53497/regular-expression-that-matches-valid-ipv6-addresses — PerroVerd, Apr 19 '16 at 13:46

score 0 · Answer 1 · answered Apr 19 '16 at 12:49

0

Why don't you use built-in linux utility,
ipcalc --ipv6 1111:2222:3333:4444::
If it returns nothing then you've provided correct IP
If you provide incorrect IP it returns something like,
ipcalc: bad IPv6 address:

Hope it helps.

answered Apr 19 '16 at 12:49

Mahadev Patil

109
11

I think OP wants to avoid validating IPv6 `::` shorthands – Aaron Apr 19 '16 at 13:01
ipcalc will support ipv6 address? getting syntax error – Manu Cherian Apr 19 '16 at 13:10
yes!, For ipv4: `ipcalc --ipv4`, For ipv6: `ipcalc --ipv6` – Mahadev Patil Apr 19 '16 at 13:14
ipcalc --ipv6 2001::af03::1001:0011 Unknown option: --ipv6 – Manu Cherian Apr 20 '16 at 09:00
Check your version of `initscripts` by `rpm -aq | grep initscripts`, it should be version 9 or above to support `ipv6` – Mahadev Patil Apr 20 '16 at 09:12

score -1 · Answer 2 · answered Apr 19 '16 at 12:59

-1

This regular expression should do the trick :

([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}

It matches 8 blocks of 1 to 4 hexadecimal values, joined by 7 :.

answered Apr 19 '16 at 12:59

Aaron

24,009
2
33
57

ipv6 validation using regex

2 Answers2