Thanks for input. Basically hash will group keys with duplicate values. I replaced with new code by commenting-out warn message with duplicate keys. While in execution, there is error "Global symbol "$hash" requires explicit package name at ./file_name.pl line 69." I don't have hash_ref to hash, to my understanding, without defining hash_ref we can't refer to/and have data written in hash table. Please correct. 

sub mainCSV
{
    # Open the CSV input file
    open (my $infile_CSV1, '<', "$infile_CSV") or die "Unable to open 
+$infile_CSV: $!\n";
    my %hash  = (); 
    my $hash_ref = \%hash;
    
    while (my $line = <$infile_CSV1>) 
    {
        chomp;
        $line =~ s/\s*\z//;
        my @array_CSV = split /,/, $line;
        my $key_CSV = shift @array_CSV;
        push @{ $hash->{$key_CSV} }, $_ foreach @array_CSV; ++++ Error
+ ++++
        print Data::Dumper->Dump([ \@array_CSV, $hash], ["array_CSV", 
+"hash"] ); ++++ Error +++++
        #if ($hash{$key_CSV})
        #{
        #    warn "Duplicate key '$key_CSV'";
        #};
        #$hash{$key_CSV} = \@array_CSV;
    }
    
    # Explicit scalar context 
    my $size = scalar keys %hash; 
    
    # Open the output file and save hash in $outfile_RX_CSV
    #open (my $outfile2, '>', "$outfile_CSV") or die "Unable to open $
+outfile_CSV: $!\n";
    #print $outfile2 Dumper(\%hash); 
    #close $outfile2;
    #print "Stored $size list of pins in $outfile_CSV file.\n";
    
    # Return a reference to the hash.
    #return %hash;
}

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In reply to Re^6: csv to hash table by waytoperl
in thread csv to hash table by waytoperl

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