open( RTR, "$rtrlist" ) || die "Can't open $rtrlist file";
...
open( LOG, ">$workingdir/RESULT.TXT" )|| die "Can't open $workingdir/RESULT.TXT file";
...
$rtr = `$snmpget .1.3.6.1.4.1.9.2.1.3.0 $snmpro[0] $rtr` or print "hostname failed: $!\n";
...
	$rtr = `$snmpget .1.3.6.1.4.1.9.2.1.3.0 $snmpro[1] $rtr` or print "Host not responding to $snmpro[1]\n";