If you have a non-tty-shell there are certain commands and stuff you can't do. This can happen if you upload reverse shells on a webserver, so that the shell you get is by the user www-data, or similar. These users are not meant to have shells as they don't interact with the system has humans do.
So if you don't have a tty-shell you can't run **su**, **sudo** for example. This can be annoying if you manage to get a root password but you can't use it.
So if you don't have a tty-shell you can't run `su`, `sudo` for example. This can be annoying if you manage to get a root password but you can't use it.
Anyways, if you get one of these shells you can upgrade it to a tty-shell using the following methods:
