use strict;

my $path = '/var/www/html';
print "<ul>\n";
recurse_path($path, "  ");
print "</ul>\n";

sub recurse_path {
  my $path = shift;
  my $padding = shift;

  my $dir = $path;
  $dir =~ s/.*\///g;
  print "$padding<li><a href=\"$path\">$dir</a>\n";

  my $has_subdir = 0;
  foreach(glob("$path/*")) {
    if(-d $_ && ! $has_subdir) {
      print "$padding<ul>\n";
      $has_subdir = 1;
      recurse_path($_, $padding . "  ")
    }
    elsif(-d $_) { recurse_path($_, $padding . "  ") }
  }
  if($has_subdir) { print "$padding</ul>\n" }
}