Regex for API subdomains

Question

I would like to have a regex that matches the following domains:

But does not match on the followings:

I have tried this: ^[a-z]+.[a-z-]*api.company.com$ but it not working, and I can not make it work. Can you help me please?

I am using javascript String.match() function.

So, the formula is that first string before dot shouldn't have a hyphen? — gurvinder372, Mar 07 '16 at 13:52
@gurvinder372 yeah, but `api.company.com` shouldn't match either... so — ʰᵈˑ, Mar 07 '16 at 13:52
no, it can have. I can be d-ev.api.company.com but can not be d-ev-api.company.com there like X.Xapi.company.com but not Xapi.company.com X can be anything. — Rajaswami, Mar 07 '16 at 13:53
Is the formula, "(1) must end with the string `api.company.com`, and (2) the left-most subdomain part cannot be hyphenated or the exact string `api`"? — apsillers, Mar 07 '16 at 13:58
@apsillers I updated the list. The point is I need one more level before .[somethingOrNothing]api.company.com — Rajaswami, Mar 07 '16 at 14:00
What I understand, you only want 4th level domains and reject everything else. e.g you want `live.api.company.com` but not `api.company.com` — Saleem, Mar 07 '16 at 14:07
Do you tolerate *more* than four levels? Or only exactly four? — apsillers, Mar 07 '16 at 14:08

score 3 · Accepted Answer · answered Mar 07 '16 at 14:06

3

Try the following regex:

^[a-zA-Z0-9]+\.[^\.]*api\.company\.com$

answered Mar 07 '16 at 14:06

razz

Adrian B. · Answer 2 · 2016-03-07T14:01:20.417

1

Consider the following:

if (string.matches("^(dev\\.api|live\\.api|test\\d+)\\..*$")) {
    // Accepted subdomain
} else {
    // Nope
}

You can enter as many options as you want, separating them with |

Breakup of the regex:

^ - starts with

(option1|option2|option3) - a list of accepted subdomains

\. - a subdomain must be followed by a period

.*$ anything else until the end of the string

This solution allows you to administer the accepted subdomains easily if you don't have a general rule of thumb for selection.

edited Mar 07 '16 at 14:01

answered Mar 07 '16 at 13:53

Adrian B.

Thank you, but dev and live are just example. they can be anyhting. not just dev or live it should match devxxx.api.company.com too. But not on devxxx-api.company.com – Rajaswami Mar 07 '16 at 13:55
without a rule for the accepted domains, we can't realy make a rule to select anything... – Adrian B. Mar 07 '16 at 13:56

score 0 · Answer 3 · edited Mar 07 '16 at 15:32

0

Try this:

/^[a-z\\.\\-]{0,}api.company.com$/

Tests against your examples and it works.

edited Mar 07 '16 at 15:32

twernt

answered Mar 07 '16 at 13:57

shiroma

1

this also accepts the subdomains asked to be ignored. – Adrian B. Mar 07 '16 at 13:58

3 Answers3