Shell Programming and Scripting

my $cnt;
my $cnt1;
my $f = $datFile."_Column.dat";
my $datFile1= $datFile."_null.dat";
open my $fh_in,  "<", "$datFile"  or die "Could not open $datFile: $!\n";
open my $fh_out, ">", "$f" or die "Could not create $f: $!\n";
while ( my $line = <$fh_in> ) {
    my $first_column = (split /\t/, $line)[0];
    print $fh_out "$first_column\n";
}
close $fh_in;
close $fh_out;
open my $fh_in1,  "<", "$f"  or die "Could not open $f: $!\n";
open my $fh_out1, ">", "$datFile1" or die "Could not create $datFile1: $!\n";
while ( <$fh_in1> ) {
    if (/\S/) {
        print $fh_out1 $_;
    }
}
open(FH,$datFile) or die "Damn. $!";
$cnt++ while <FH>;
close FH;
print "$cnt\n";
open(FHN,$datFile1) or die "Damn. $!";
$cnt1++ while <FHN>;
close FHN;
print "$cnt1\n";
$logger->info($ID." ".$cnt." Check count cnt");
$logger->info($ID." ".$cnt1." Check count cnt1");

open(FHN,$datFile1) or die "Damn. $!";
$cnt1++ while <FHN>;
close FHN;
print "$cnt1\n";

open(FHN,"$datFile1") or die "Damn. $!";

open(FHN,"$datFile1") or die "Damn. $!";