I the have following setup in my conf file
upload_set_form_field $upload_field_name.name "$upload_file_name";
But I want change chosen param name to:
upload_set_form_field ($upload_field_name+"[name]") "$upload_file_name";
So I can get "attachment[name]" but this doesn't work. I would be very happy if someone could help me with merging variables with string in nginx config file :).