sub _arg_validation {
    my $args = shift;
    my $dir  = "$ENV{HOME}/vk_music/";
       $dir .= "$args->{dir}/" if defined $args->{dir};
    mkdir $dir;
    $args->{dir} = $dir;
    return 1 if defined $args->{login}                    &&
                defined $args->{password}                 &&
                        $args->{login}    =~ /^.*?\@.*?$/ &&
                        $args->{password} =~ /\w{2,}/;
    return 0;
}