regular expression for validating url with sub-domain

Question

preg_match('/^(http:\\/\/)?(.+)\.MYDOMAIN\.com(.*)/', $url, $match)

This is my regex to validate a URL that must have a sub-domain, but if someone uses www instead of sub-domain it also gets validated. For example:

http://shoes.en.MYDOMAIN.com/ This must pass
http://www.MYDOMAIN.com/ This must fail

How can I edit my regex to fail if the sub-domain is www?

Use backticks to format URLs: http://www.MYDOMAIN.com/. That will stop SO from linkifying them, and from dropping the http:// in comments. — Alan Moore
– Alan Moore, Commented Apr 12, 2012 at 11:31

Billy Moon · Accepted Answer · 2012-04-12 06:55:32Z

2

I think you can do it with a negative lookahead assertion: (?!www\.) which being placed after the protocol check, checks if there is not a www. following the start or protocol.

/^(http:\\\/\/)?(?!www\.)(.+)\.MYDOMAIN\.com(.*)/.test("www.MYDOMAIN.com")

answered Apr 12, 2012 at 6:55

Billy Moon

58.9k27 gold badges148 silver badges245 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Atif Ali Over a year ago

This is getting failed when i use http. The regex is passing sd.MYDOMAIN.com It must be failed as it has www

Atif Ali Over a year ago

shoes.trustpass.MYDOMAIN.com why is this getting pass??? It works fine if I remove http://. After submitting stackoverflow removes http and www from the url. Kindly add http and www at starting of provided URL

k102 · Accepted Answer · 2012-04-12 06:40:17Z

0

try this one: tested a litle, seems to be working

preg_match('/^(http:\\/\/)?([^(www)]+)\.MYDOMAIN\.com(.*)/', $url, $match);

answered Apr 12, 2012 at 6:40

k102

8,1099 gold badges52 silver badges72 bronze badges

4 Comments

Billy Moon Over a year ago

Does not do what you are expecting. The www is actually treated as character class, so equivalent to w and matches any subdomain that does not contain a w.

Billy Moon Over a year ago

you are also missing an escaping slash in the protocol

Atif Ali Over a year ago

This is getting failed if my subdomain starts with www. Like wwwshoes

Atif Ali Over a year ago

It even fails if subdomian has www anywhere in it.

msam · Accepted Answer · 2012-04-12 09:19:24Z

0

How about first validate the domain using your current solution then check for www using a second expression:

(\.www\.|http:\/\/www\.|^www\.)

edited Apr 12, 2012 at 9:19

answered Apr 12, 2012 at 7:23

msam

4,2873 gold badges21 silver badges32 bronze badges

Collectives™ on Stack Overflow

regular expression for validating url with sub-domain

3 Answers 3

2 Comments

4 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

4 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related