while (<$fh>) {
   chomp;
   my ($host, $ip) = split;
   warn("bad hosts line: $_"),next if !defined $ip;
   $hosts{$host} = $ip;
}

##</code><code>##

%hosts = map {
   if (/^(\w+)\s(.+)/) {
      ($1 => $2)
   } else {
      (warn "bad hosts line: $_")[1..0];
   }
} <FILE>;