#!/usr/bin/perl -l

use strict;
use warnings;
use File::Find;
use constant QUOTA => 4.7 * 2**30;

sub wanted ();

@ARGV = grep { -d or !warn "Not a directory: `$_'\n" } @ARGV;
die "Usage: $0 <dir> [<dirs>]\n" unless @ARGV;

my ($size,$cnt)=0;
find { no_chdir => 1,
       wanted => \&wanted }, @ARGV;

sub wanted () {
    return unless -f;
    print 'List ', $cnt++, ':' unless $size;
    my $sz = -s _;
    warn "Too big single item: `$_'\n" and
      return if $sz >= QUOTA;
    my $newsz=$size + $sz;
    if ($newsz<QUOTA) {
        print;
        $size=$newsz;
    } else {
        print '';
        $size=0;
        wanted;  # "redo"
    }
}

__END__