bash - how can i check IP version ( 4 or 6) in shell script -

i want check whether ip of version 4 or version 6. input ip address in string form. example :

ip version 4 --> 1.1.1.1 ip version 6 --> 12:1201::12:15 

you check if string contains colon :, ipv6 address, otherwise ipv4 addresss:

string='1.1.1.1';  if [[ $string =~ .*:.* ]]   echo "ipv6" else   echo "ipv4" fi