Detect partial email pattern in PHP [closed] - php

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I am writing an unsubscribe option of email newsletters.
I have to detect emails of following format:
<0 or more alphanumeric letter/digit only>, then one <#> character, then <1 or more alphanumeric letter/digit>, then a <.> character, then <at least 2 alphanumeric letter/digits>
I need "zero" or more alphanumeric character before # character and not "one" or more because sometimes I want to unsubscribe whole domain names, so in that case the pattern to match is #example.com, and I also want to detect full email, it starts with an alphanumeric character.
How can I write the code to detect?
I take the email from url as $_GET['email']
For example url will be:
http://www.example.com/php/unsubscribe.php?email=#example.com
http://www.example.com/php/unsubscribe.php?email=#example.co
http://www.example.com/php/unsubscribe.php?email=abc#example.co

Answer 1

well the Regex then simply reads
/#.+\.[^\.]{2,}$/
EDIT: I used .* and [^\.] even though the OP asked for "alphanumeric letter/digit" - however, valid E-Mail addresses include stuff like dashes, underscores etc... Completely matching ALL valid email adresses is incredibly complex! (see: http://www.regular-expressions.info/email.html)

Answer 2

You could use the below regex.
[A-Za-z0-9]*#[A-Za-z0-9]+\.[A-Za-z0-9]{2,}
DEMO
[A-Za-z0-9]{2,} matches two or more alphanumeric characters. You could specify the character range inside {} paranthesis.