#!/usr/bin/perl

$period = $ARGV[0] || 1;

sub get_dl_ul {
	$dl = `dl`; chomp $dl;
	($dl, $ul) = split /\t/, $dl;
}

get_dl_ul();
while(1) {
	$old_dl = $dl; $old_ul = $ul;
	sleep($period);
	get_dl_ul();
	$dl_rate = ($dl - $old_dl) / $period;
	$ul_rate = ($ul - $old_ul) / $period;
#	print "$old_dl\t$old_ul\n";
#	print "$dl\t$ul\n";
	print "$dl_rate\t$ul_rate\n";
#	print "\n";
}