To split on any amount of whitespace, use a regular expression:

($fn,$ln) = split(/\s+/,$input);
[download]

Note that you'll get only the first two words without the third argument to split - the number of fields you want to split into:

$input = "foo bar blurf";
($f,$s) = split /\s+/, $input;
print "<$f> <$s>\n"
__END__
<foo> <bar>
[download]

$input = "foo bar blurf";
($f,$s) = split /\s+/, $input, 2;
print "<$f> <$s>\n"
__END__
<foo> <bar quux>
[download]

--shmem

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}