Re^2: Should I worry about "Inappropriate ioctl for device"?

[karlgoethebier]

You may read this by brian_d_foy. $ERRNO is not what you want.

One option might be to rewrite you code like this:

sub four_digit_year {
   my $year = shift;
   if ( $year !~ /\d{4}/ ) {
     return; # undef
   }
   return $year;
}

Then check if the result of your sub call is defined and die with some custom error message if not.

And probably you may find a more robust recipe on PM how to test if some date is valid.

Best regards, Karl