Question

So I want to match just the domain from ether:

http://www.google.com/test/
http://google.com/test/
http://google.net/test/

Output should be for all 3: google

I got this code working for just .com

echo "http://www.google.com/test/" | sed -n "s/.*www\.\(.*\)\.com.*$/\1/p"
Output: 'google'

Then I thought it would be as simple as doing say (com|net) but that doesn’t seem to be true:

echo "http://www.google.com/test/" | sed -n "s/.*www\.\(.*\)\.(com|net).*$/\1/p"
Output: '' (nothing)

I was going to use a similar method to get rid of the “www” but it seems im doing something wrong… (does it not work with regex outside the \( \) …)

Answer 1

This will output “google” in all cases:

sed -n "s|http://\(.*\.\)*\(.*\)\..*|\2|p"

Edit:

This version will handle URLs like “‘http://google.com.cn/test” and “http://www.google.co.uk/” as well as the ones in the original question:

sed -nr "s|http://(www\.)?([^.]*)\.(.*\.?)*|\2|p"

This version will handle cases that don’t include “http://” (plus the others):

sed -nr "s|(http://)?(www\.)?([^.]*)\.(.*\.?)*|\3|p"