CODEWITHSUNDEEP
regex
Delos Chang
Delos Chang

Reputation: 1853

Regex for multiple specific email addresses

I am still figuring my way around regex and have come across a problem that I am trying to solve. How do I validate for multiple specific email addresses?

For example, I want to only allow testdomain.com, realdomain.com, gooddomain.com to be validated. All other email addresses are not allowed.

[email protected]   OK
[email protected]  OK
[email protected]   OK

[email protected] NOT OK

But I'm stil unclear on how to add multiple specific email addresses for the regex.

Any and all help would be appreciated.

Thank you,

Upvotes: 0

Views: 195

Answers (6)

Ωmega
Ωmega

Reputation: 43703

The official standard is known as RFC 2822.

Use OR operator | for all domain names you want to allow. Do not forget to escape . in the domain.

[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:testdomain\.com|realdomain\.com|gooddomain\.com)

Also use case-insensitivity modifier/flag to allow capital letters in the address.

Upvotes: 0

TylerOhlsen
TylerOhlsen

Reputation: 5578

To make this expandable to many domains, I would probably capture the domain name and then compare that captured domain name with your whitelist in code.

.+@(.+)

First, ".+" will match any number (more than 0) of any characters up until the last "@" symobol in the string. Second, "@" will match the "@" symbol. Third, "(.+)" will match and capture (capture because of the parenthesis) any character string after the "@" symbol.

Then, depending on the language you are using, you can get the captured string. Then you can see if that captured string is in your domain whitelist. Note, you'll want to do a case insensitive comparison in this last step.

Upvotes: 0

user1726343
user1726343

Reputation:

Assuming the above works for testdomain:

\b[A-Z0-9._%-]+@(?:testdomain|realdomain|gooddomain)\.com\b

Also, please note that you will have to add a case insensitive i modifier for this to work with your test cases, or use [A-Za-z0-9._%-] instead of [A-Z0-9._%-]

See here

Upvotes: 0

David
David

Reputation: 6561

You didn't specify which language you're using, but most regex implementations have a notion of logical operators, so the domain part of your pattern would have something like:

(domain1|domain2|domain3)

Upvotes: 2

Tulains Córdova
Tulains Córdova

Reputation: 2639

\b[A-Z0-9._%-]+@(testdomain|realdomain|gooddomain)\.com\b

Upvotes: 1

Billy Moon
Billy Moon

Reputation: 58619

Do you mean to include various ligitimate domains in one regex?

\b[A-Z0-9._%-]+@(testdomain|gooddomain|realdomain)\.com\b

Upvotes: 3

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