my $info = $ENV{'PATH_INFO'};
print "Raw Info: $info\n";
my $header = '';
if ($info =~ m{^[-_/A-Za-z0-9]+\.(gif|jpg)$})
  { $header = "Content-type: image/" . $1; }
unless ((length ($info) > 0) && (length ($header) > 0) && (-f $info)) 
  {
  $info = "/z.gif";
  $header = "Content-type: image/gif";
  }

print "Info:   $info\n";
print "Header: $header\n";