There's no .tar involved !?

BTW: in addition to the valueable links already given, you could simply invoke the Zlib-module from CPAN:

 ...
 use IO::Zlib;

 my $file = "IpToCountry.csv.gz";
 my $end_file = "IpToCountry.csv";

 my $fh = IO::Zlib->new($file, 'rb');
 if(defined $fh) {
   open my $fd, '>', $end_file or die "$end_file $!";
   while(my $line = <$fh>) { print $fd $line }
   undef $fh;
 }
 ...
[download]

This will extract the .csv.gz to a .csv

Regards

mwa