Unable to compare ping times on fly

Question

I tried the following command unsuccessfully

sdiff <(ping www.nato.int) <(ping www.reuters.com)

Is there any way to have a real-t

Answer 1

Usually I just open two xterms side-by-side and run ping in each. Or in one terminal "ping host1 & ping host2&"

fping -e will give you the latency to a list of hosts in one run. So you can just do: watch fping -e www.google.com www.yahoo.com www.kernel.org

Not everyone has watch, but you can just do this (and then you can see the history): while :; do date; fping -e www.google.com www.yahoo.com www.kernel.org; sleep 1; done

The output is still ugly, and not everyone has fping installed either..

Here's a start if you want to produce decent looking output. Just give it a list of hosts as arguments.

#!/usr/bin/perl
use strict;
use warnings;
use POSIX;

for(;;) {
    print strftime("%T:", localtime);
    foreach my $host (@ARGV) {
        my $a=`ping -c 1 $host`;
        my $latency;
        if($a =~ /rtt.* =\s+([\d.]+)\//s) {
            $latency=$1;
        } else {
            $latency="(dropped)";
        }
        print "$host:$latency\t";
    }
    print "\n";
    sleep(1);
}