#!/usr/bin/env perl -l

use strict;
use warnings;

{
    local $/ = '';

    while (<DATA>) {
        chomp;
        print '--- One Block ---';
        print;
    }
} 

__DATA__
Block1 Line1
Block1 Line2
Block1 Line3


Block2 Line1
Block2 Line2
Block2 Line3



Block3 Line1
Block3 Line2
Block3 Line3

Block4 Line1
Block4 Line2
Block4 Line3