regex-urls-domains.md

Examples of regex and wildcards with domains and URLs

MATCH REGEX

• any subdomain of example.com (\.|^)example\.com$
• any subdomain of example.net (\.|^)example\.net$
• ads as subdomain but not known TLD (\.|^)ads\.$
• xxx as top-level-domain but not known subdomain nor domain (\.|^)\.xxx$

Then you could try something like this, for keyword multi-string in the domain name.

(\.)(adult|ads|adverts|advertising|click|porn|sex|telemetry|tracking|tracing)$

More about this in my Pi-hole repo with regex here

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Strip sub-domains to root domain (Find)

Example Notepad++

Use this as the FIND context and use REPLACE with blank.

^[^.]*\.(?=\w+\.\w+$)

Explained:

^ = start of line
[^.]* = any number of chars that are not a dot
\. = a dot
(?=[^.]+\.[^.]+$) = there must be exactly one word, one dot then one word from here to the end

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Strip port numbers at end of URL

Regular Expression string:

:[\d]+$

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Strip down full URL to domain name

https://www.google.com/api?=login/someshit/0931750135145/

to be just

www.google.com

Usage could be for a sysadmin or someone to get just the domain name / subdomain needed for a task/action in role.

^http:..|^https:..|\/.*

Regex validated here

Of course you could replace the text to be something else instead of url and domain strings (you get the picture I hope).

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Convert a HOSTS list to EasyList/AdGuard format

Debian CLI: sed 's/^/||/' pihole-format.txt > easylist-format.txt

In a text editor GUI try this:

(usually Ctrl+H on Windows for 'replace') find string/what: ^ replace string/what: \1\|| or || Enable Regular Expression, Tick Matches newline. Click Replace All

and/or, Find $ and replace with ^$important - this will add ^$important to the end of each line