in reply to Re^2: 'Invisible' newlines/line wrapping
in thread 'Invisible' newlines/line wrapping

You deserve a reference to read about those differences
From warnings:
The warnings pragma is a replacement for the command line flag -w , but the pragma is limited to the enclosing block, while the flag is global. See perllexwarn for more information.
Also: perllexwarn
  • Comment on Re^3: 'Invisible' newlines/line wrapping (-w)

In Section Seekers of Perl Wisdom