use strict;
use warnings;

use Data::Dumper;
$Data::Dumper::Indent = 0;

my $file = "test";
my @data;

{
    local $/ = undef;
    open FILE, "$file" or die $!;

    while (my $line = <FILE>) {
        push @data, split /XXX/, $line; 
        # I thought it should be /^XXX$/, but that didn't work
    }
}

@data = grep /\S/, @data; # I don't understand why I had to do this

print Dumper \@data;