use strict;
use warnings;

my $dir=shift || die "Directory where the chunks are stored\n";
my $out=shift || die "Name under which we join the chunks\n";
my @files;
my $buffer;
opendir(D,$dir) || die "OPENDIR : $!\n";
@files=grep { /^\d+$/ } readdir(D);
closedir(D);
chdir($dir) || die "CHDIR : $!\n";
open(F,">../$out") || die "CREATE : $!\n";
binmode(F);
@files=sort { $a <=> $b } @files;
for(@files) {
	open(C,$_) || die "OPEN : $!\n";
        binmode(C);
	while(read(C,$buffer,4096)) {
		print F $buffer;
	}
	print "I joined chunk nr. $_\n";
	close C;
}
print "File $out is complete now\n";
close F;