UNIX for Beginners Questions & Answers

Hello guys,
Here i am writing a script in bash to check for a valid URL from a file using regex
This is my input file

Code:

http://www.yahoo.commmmmm
http://www.google.com
https://www.gooogle.co
www.test6.co.in
www.gmail.com
www.google.co
htt://www.money.com
http://eeeess.google.com
https:/ww.test.c.in

#my script

Code:

URL=$(grep -E -o   "^(http(s)?://)?+(w{3}\.)+([a-z0-9]{1,64}\.)+\w{2,3}" $path )

What my output is:

Code:

http://www.yahoo.com
http://www.google.com
https://www.gooogle.co
www.test6.co.in
www.gmail.com
www.google.co

here it is trimming the htttp://www.yahoo.commmmmm
Help me out from this

You asked it to trim to at most 3 with {2,3}.

I think you are over-simplifying the issue. I don't think that there is no way for certain to know if names exist with a regular expression. You cannot just assume that the last part of a domain name (the Top Level Domain) is a 2 or three characters only.

List of Internet top-level domains - Wikipedia


You might have to trim out the domain name from the full URL & perform a get to the real site to see if you connect. That might be the only way.
You can see the problem. The list (if you could even build one) would be huge and would be frequently updating. Perhaps a DNS query would give you enough though.

Code:

host $extracted_domain_name >/dev/null
if [ $? -eq 0 ]
then
   echo "DNS entry exists"
else
   echo "It is an invalid domain"
fi

Does that help?




Robin