From an administration screen I want to be able to see a list off all current sessions. I do not need to see any of the session variables (but am interested if this can be done). I just want to know if session xxxxxxx is still active.
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions.
Consider email address RFCs:
Look at HTML5 form input element (with type=email) regex pattern: