use Net::SSH::Perl
# vars to set: $user, $password, $host, $local_fqn, $rmt_dir
open STDOUT, ">$local_fqn" or die "Can't redirect stdout";
select STDOUT; $| = 1;         # make unbuffered
$cmd="tar -czf - $rmt_dir";
my $ssh = Net::SSH::Perl->new($host);
$ssh->login($user, $password);
my($stdout, $stderr, $exit) = $ssh->cmd($cmd);
close STDOUT;