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

my $ping = "/usr/sbin/ping";
while (<DATA>){
  chomp;
  my $ping_out = `$ping $_ 2> /dev/null`;
  chomp ($ping_out);
  if ($ping_out !~ /is alive/){ print "$_ isn't pinging\n"; }
}

__DATA__
server1
server2
server3