get '/analysis' => sub {
    if (session('user')  && session('logged_in')) {
    open FH, "<", "./scripts/test.out";
    my $msg = <FH>;
    close FH;
    chdir ("./scripts");
    system("call sth"); #call external programs to generate a "test.png"
    my $err;
    copy ("test.png", "../public/images/test.png") || ($err = "cannot copy"); #copy the "test.png" to public/images directory, so the html tt can use it
    my $img = "test.png";
       template 'analysis',{msg => $msg, img => $img, err => $err};
    }
    else {
    return redirect '/'
   }
};