#!/usr/bin/perl 
use strict;
use warnings;

my $HSSIN='D:\testproject\HSS-export-test-run-small.txt';
my $ofile = 'D:\testproject\HSS-output.txt';
open (INFILE, $HSSIN) or die "Can't open input file";
open (OUTFILE,"> $ofile" ) or die "Cant open file"; 


my $content = undef;
{undef $/; $content = <INFILE> } close(INFILE);

my $num_found = 0;
while( $content =~ /\t*CF=(CFU-TS10-ACT-(NONE|\d+))/g ){ $num_found++ }
print "multiple cases: $num_found cases of ... " if $num_found > 0;

...