use v5.10;
my $str = qq{abc\0def};
my $pck = pack q{Z*}, $str;
say sprintf q{%02x}, ord for split m{}, $pck;
say q{-} x 5;
say join ",", unpack q{Z5Z*}, $pck;
__DATA__
61
62
63
00
64
65
66
00
-----
abc,ef