After upgrading from Mac OS 10.4 to 10.5 I haven't been able to get PHP5 to work on my system. Working with PHP is a large part of my workload, and I'm trying to figure out how to fix the problem. One option I'm left with is returning to 10.4 where PHP worked.
What steps would I take to downgrade to 10.4 from 10.5?
Many old projects have bad code, but the budget doesn't exist to rewrite the codebase. You can update this code to be safer by introducing contemporary input validation, sanitation, and safer database queries.
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: