my $aoh = csv (in => $xFile[$k], headers => "auto", callbacks => {
    after_parse => sub { $_ ||= 0 for @{$_[1]} }});

##</code><code>##

$ cat test.pl
#!/pro/bin/perl

use 5.16.2;
use warnings;

use Text::CSV_XS qw(csv);
use Data::Peek;

DDumper (csv (in => *DATA, headers => "auto", callbacks => {
    after_parse => sub { $_ ||= 0 for @{$_[1]} }}));

__END__
a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K
11004516,0,0,9,9,3,12477,,,4,,0,,,3,38a947a1,b66b7850,6a14f9b9 11006995,1,,-1,,,,,
$ perl test.pl
[
    {   A                => 0,
        B                => 0,
        C                => 0,
        D                => 0,
        E                => 0,
        F                => 0,
        G                => 'fbc55dae',
        H                => '9a89b36c',
        I                => '58e67aaf',
        J                => 'f600ec0b',
        K                => 0,
        a                => 11004516,
        b                => 0,
        c                => 0,
        d                => 9,
        e                => 9,
        f                => 3,
        g                => 12477,
        h                => 0,
        i                => 0,
        j                => 4,
        k                => 0,
        l                => 0,
        m                => 0,
        n                => 0,
        o                => 3,
        p                => '38a947a1',
        q                => 'b66b7850',
        r                => '6a14f9b9 11006995',
        s                => 1,
        t                => 0,
        u                => -1,
        v                => 0,
        w                => 0,
        x                => 0,
        y                => 0,
        z                => 0
        }
    ]

##</code><code>##

my $csv = Parse::CSV->new (
    file           => $xFile[$k],
    header         => "auto",
    names          => 1,
    empty_is_undef => 1,
    auto_diag      => 1,
    callbacks      => {
        after_parse => sub { $_ ||= 0 for @{$_[1] }
        },
    ));