I've just discovered very important differences between Windows an Unix formats in Perl,at least 5.xx..
Use Unix file format while saving Your script.
otherwise it will have ^M s or smth likely weird in the EOL,
Then DO NOT use m…
On Microsoft Windows, if when you click or type the name of a .pl file, you get an error "is not recognized as an internal or external command, operable program or batch file", then this means you do not have the .pl file extension associated with …
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: