my %supHash

open my $ref, "ref.txt" or die $!;
$head = <$ref>; ## if header is present
while(<$ref>){
chomp $_;
my @line = split(',', $_);  ## if it is a csv file
if(exists $CommonSampleNames{$line[0]} ){
$supHash{$ine[0]} = $line[1]; ## if second column has reference names
}

}
close($ref);