You can also find out what you split on:

$str = "what's up, doc?";
for (split /(\W+)/, $str) {
  print "<$_>\n";
}
__END__
<what>
<'>
<s>
< >
<up>
<, >
<doc>
<?>
[download]

$_="goto+F.print+chop;\n=yhpaj";F1:eval