use strict;
use warnings;
my @hostnames = qw(www.leo.org dhbvg.xxx);
foreach (@hostnames){
   # my $a = `echo pinging $_ 1>&2 ; ping -c3 $_ 2>&1 | tee -a /dev/tty`;
   my $a = `ping -c3 $_ 2>&1`;
   if ($a =~ /unreach|unknown host/i){
      print " For $_ : problems: $a.";
   }
}