#!perl -w
use strict;
use CGI ":standard";

my $longest = "";
my $dir = '/data';

opendir DIR, $dir or die "Couldn't readdir $dir"; 
while(my $file = readdir DIR) {
  print "'$longest'\n";
  $longest = $file if length($file) > length($longest);
} 
closedir DIR; 

print header,
  start_html("Longest filename"),
  "Longest filename in '$dir' is '$longest', which has ",
  length($longest),
  ' characters.',
  end_html;