And this shows how to abstract reading [CST]SV files and keep sane:

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

use Crypt::CBC;
use Text::CSV;

use Data::Dumper;

my $type = "en";
my $key = "12345";
my $file = "data.txt.encrypt";

my $DEBUG = 1;

print "type is $type, key is $key, file is $file\n" if $DEBUG;

my $cipher = Crypt::CBC->new(
    -key    => $key,
    -cipher => 'Blowfish'
);

my $data = Text::CSV::csv(
    in => $file,
    sep_char => ' ',
    headers => 'auto',
    keep_headers => \my @headers
);
if( ! $data ){ print STDERR "$0 : call to Text::CSV::csv() has failed 
+for input file '$file'.\n"; exit(1) }
print Dumper($data) if $DEBUG;

my ($outfile, $cipher_coderef);
if( $type =~ /^en(crypt)?$/ ){
    $cipher_coderef = sub { return $cipher->encrypt($_[0]) };
    ($outfile = $file) =~ s/encrypt/decrypt/;
} else {
    $cipher_coderef = sub { return $cipher->decrypt($_[0]) };
    ($outfile = $file) =~ s/decrypt/encrypt/;
}

my @columns_to_encrypt = ('customerid', 'age');
my $rid = 0;
foreach my $row (@$data){
    $rid++;
    foreach my $colname (@columns_to_encrypt){
        print "$0 : row $rid, column '$colname' : processing ...\n";
        $row->{$colname} = $cipher_coderef->($row->{$colname});
    }
}

if( ! Text::CSV_XS::csv(
    in => $data,
    sep_char => ' ',
    headers => \@headers,
    out => $outfile
) ){ print STDERR "$0 : call to Text::CSV_XS::csv() has failed.\n"; ex
+it(1) }
print "$0 : success, output in '$outfile'.\n";
[download]