# $sock is open, probably is a IO::Socket of some type

my $total_read = 0;
my $full_data = '';
my $total;

while ( 1 ) {
	my $read = 0;
	while ($read < 4) {
		$read += read($sock,$data,4-$read,$read)
		# not sure if last arg should have a +1 on it
	}
	$total_read += $read;
	
	if (! $total) {
		$total = unpack("N",$data);
	}
	elsif ( $total_read >= $total + 4 ) {
		process(substr($data,0,$total_read-4-$total));
		$full_data .= substr($data,0,$total_read-4-$total);
		last;
	}
	else {
		$full_data .= $data;
		process($data);
		other_process($full_data);
	}
}

full_process(substr($full_data,0,$total));