The regular expression you've used in the split is a bit odd. \s+ matches \n, so the regex is mostly redundant. The one difference can be seen with these two snippets:

my @fields = split ' ', "abc\n  def";
my @fields = split /\n|\s+/, "abc\n  def";
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The first splits on "\n ", producing ('abc', 'def'), while the second splits on "\n" and " ", producing ('abc', '', 'def'). In other words, split /\n|\s+/ will give you null strings where there's a newline followed by whitespace (including blank lines).

One other point; your code depends on having exactly six slots. You might consider writing it to work with any number of slots.