replacing multiple blank lines with a single blank line

[Moore, Larry]

I want to slurp a file and make multiple blank lines into single blank
lines. Here is my code:
 
#! perl -w
use strict;
 
my $file = "test.fmt";
 
open (IN, $file) or die;
open (OUT, ">>test.txt");
 
my $text;
 
{
  local $/;
  $text = <IN>;
  close IN;
}
 
# $text =~ s/\0{2,}/\0\0/mg; # this removes all the blank lines
 
#  $text =~ s/(^$^$)(^$)+/$1/mg; # also removes all blank lines and
complains
 
# $text =~ s/(\n\n)(\n)+/$1/mg; # no improvement here either
 
print OUT "$file\n\n$text\n******************";
close OUT;

 
I have tried a number of substitutions but haven't found the correct
formulation.
 
surely I am missing something simple here.  
 
Larry