【Perl 】初心者コーナーPart5

>511
↓でだめか？

my($host) = &nslook($ENV{'REMOTE_ADDR'}) || '???';

sub nslook{
my($x) = shift;

($x =~ /([0-9]+)\.([0-9]+)\.([0-9]+)\.([0-9]+)/)
? ((gethostbyaddr(pack('C4',$1,$2,$3,$4),2))[0] || $x)
: $x;
}