It seems I can't extract tar.gz files with that module.
Of course I can use system with gunzip bit I wanted to do it this way.
For Archive module I use version 0.22
The error message for this snippet is :

Can't use an undefined value as an ARRAY reference at /usr/lib/perl5/s
+ite_perl/5.005/Archive/Tar.pm line 736.
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The code snippet:

use strict;
use Archive::Tar;

my ($dirname,$file);
$dirname = "path_to_dir";

opendir(DIR,$dirname) or die "unable to open $dirname : $|";
while(defined($file = readdir(DIR))){
    my $tar = Archive::Tar->new();
    $tar->read("$file", 1);
    my @tar_files = $tar->list_files();
    $tar->extract(@tar_files);
}

closedir(DIR);
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My opinions may have changed,
but not the fact that I am right