sub get_novell_table
{
    print "Running Z:USERS /A /C... ";
    open(NL,"Z:NLIST USERS /A /C |") || die "couldn't run nlist";
    @nl = <NL>;
    close(NL);
    # Output of nlist is now in array @nl, one element per line
    # Turn into a lookup table of user names keyed by ethernet address
    foreach (@nl) {
        # parse each line into name and address
        if (/(\S+)\s*\[.*\]\[\s*(\S+)\]/) {
                $name = $1;
                $adr = $2;
                # zero extend on left hand to 12 places
                $adr = "0" x (12-length($adr)).$adr;
                $adr2name{$adr} = $name;
        }
    }
    print "Found ", 0+keys(%adr2name), " logged in Novell users.   \n";
}

# Get my own IP address
sub my_ip
{
        local($x);

        $x = `nbtstat -n`;
	if ($x =~ /\[(\d.*\d)\]/) {
		return $1;
	}
	return "";
}

sub nbtstat
{
        local(@x,$x,$ip);
        $ip = $_[0];

         $x = `nbtstat -A $ip`;
         @x = split(/\n/, $x);
         return grep(/<03>/,@x);
}
sub arp
{
        local(@x,$x,$ip);
        $ip = $_[0];

         #print "arp -a $ip \n";
         $x = `arp -a $ip`;
         #print $x;
         @x = split(/\n/, $x);
         foreach (@x) {
                if (/([\dA-Fa-f]+-.*-[\dA-Fa-f]+)/) {
                        $a = $1;
                        $a =~ s/-//g;
                        $a =~ tr/a-z/A-Z/;
                        #print "got $a\n";
                        return $a;
                }
         }
         return "";
}

&get_novell_table();
$my_ip = &my_ip();
$net = $my_ip;
$net =~ s/\.\d+$//;
open(LOG,">pingem.log") || die "Could not create pingem.log ";
select((select(LOG),$| = 1)[0]);
$low = 1;
$hi = 254;
print "Scan from: [ENTER for $low] >";
$low2 = <STDIN>; $low2 =~ s/[\s\n]*//gi; if ($low2 ne "") { $low = $low2; }
print "Scan to: [ENTER for $hi] >";
$hi2 = <STDIN>; $hi2 =~ s/[\s\n]*//gi; if ($hi2 ne "") { $hi = $hi2; }
print "Scanning for active IP addresses from $net.$low to $net.$hi.\n";
printf("%16s %20s %20s\n", "IP Address", "IPX/Ethernet Adr", "Novell Username");
for ($_=$low; $_<=$hi; $_++) {
	$x = `ping -n 2 -w 10 $net.$_`;
	$ipa = $net.".".$_;
	$nvn = "";
	$eth = "";
	if ($x =~ /reply/i) { 
                # get ethernet address
		if ($ipa eq $my_ip) {
			$eth = "This machine";
		} else {
			$eth = &arp($ipa);
		}
                # get novell user name associated with this ethernet address
                $nvn = $adr2name{$eth};
	}
	$s = sprintf("%16s %20s %20s", $ipa, $eth, $nvn);
	print $s;
	if ($eth eq "") {
		print "\r";
	} else {
		print "\n";
	}
	print LOG "$s\n" if ($eth ne "");
}
close LOG;
print "Log file available in pingem.log.\n";

#                    @x=(); @x = &nbtstat("$net.$_");
#                    if (!@x) {
#			print " no NetBios username";
#                    }
#                    foreach (@x) {
#			print "\n  $_";
#			print LOG "  $_\n";
#                    }
#                    print "\n";