#!/usr/bin/env perl
use strict;
use warnings;
use 5.016;

my $str = "\x00\x00\x01\x00\x00\x02";
my @vals;

# This works - exact multiple of 'x2C'
say "length:", length($str);
@vals = unpack "(x2C)*", $str;
say join "\n", @vals;

$str .= "\x00";

# This works - not a multiple of 'SC'
say "length:", length($str);
@vals = unpack "(SC)*", $str;
say join "\n", @vals;

# This fails - not a multiple of 'x2C'
say "length:", length($str);
@vals = unpack "(x2C)*", $str;
# ^-- dies here with: 'x' outside of string in unpack
say join "\n", @vals;