my $file = join '', @file; # put it all in a single scalar
if ($file =~ m/(?:what you want to find.*){6}/)
{
  print "'what you want to find' was in the file at least 6 times.\n";
}

##</code><code>##

my $count;
while (<$fh>)
{
  $count++ while /what you want to look for/g;
  if ($count >= 6)
  {
    last;
  }
}
$fh->close();
if ($count >= 6)
{
  print "found 'what you want to look for' at least 6 times in the file.\n";
}