for my $router (@routers) {
    get_config($router, 0);
}

....

sub get_config {
    my ($router, $retries) = @_;
    my $output = `expect -f show_running_config.exp $router->[$IP]`;
    die "Failed to get config for $router->[$NAME] at $router->[
+$IP]: $output\n" if $retries > 3 and $?;
    unless ($?) {
        sleep 5;
        $_[2] = $_[2] + 1;
        goto &get_config;
    return write_config($output, "$router->[$NAME].cfg");
}