If you are displaying plain text, use "Content-type: text/plain\n\n" instead. Otherwise, I would recommend finding an HTML primer.

---
print map { my ($m)=1<<hex($_)&11?' ':'';
$m.=substr('AHJPacehklnorstu',hex($_),1) }
split //,'2fde0abe76c36c914586c';
[download]

<p>This
will
look
like
this      does       below
[download]

This will look like this does below

The <PRE> tag means preformatted so

<PRE>
This
retains
the 
newlines
</PRE>
[download]

This
retains
the
newlines

You badly need to learn some HTML. You also need to escape the HTML special characters < > "" &

sub escapeHTML {
    my ( $escape, $text ) = @_;
  return '' unless defined $escape ;
    $escape =~ s/&/&/g;
    $escape =~ s/"/"/g;
    $escape =~ s/</&lt;/g;
    $escape =~ s/>/&gt;/g;
    # these next optional escapes make text look the same when rendere
+d in HTML
    # without wrapping in <pre> tags
    if ( $text ) {
        $escape =~ s/\t/    /g;                         # tabs to 4 sp
+aces
        $escape =~ s/( {2,})/"&nbsp;" x length $1/eg;   # whitespace e
+scapes
        $escape =~  s/\n/<br>\n/g;                      # newlines to 
+<br>
    }
    $escape =~ s/([^\000-\177])/'&#' . (sprintf "%3d", ord $1) . ';'/e
+g;
  return $escape;
}
[download]

So you need to do something like

print "Content-type: text/html\n\n";

print "<pre>\n";

for (@data) {
    print escapeHTML($_);
}

print '</pre>';

sub escapeHTML { ..... }
[download]

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print