my $count =()= 'abracadabra' =~ /br/g;
print "Found $count instances\n"
# prints Found 2 instances
##</code><code>##

sub countOverlappingMatches
{
  my $stringRef = shift;  #Likely to be huge, don't make a copy
  my $patternRef = shift;

  my $count =()= $$stringRef =~ /(?=$$patternRef)/g;
  return $count;
}

print countOverlappingMatches(\'abrabrabrabra', \'rabra');  # 3

##</code><code>##

for my $pattern (@listOfPatterns)
{
  my $count =()= $string =~ /(?=$pattern)/g;
  # Play with $count
}