Pseudo Terminals


Lets understand “Pseudo Terminals” in Linux.

You would have used your GNOME / KDE desktop environment to open the terminal (using right click -> open terminal) or from the menu options. You are doing this since your RHCE training days. 

Then you have some terminals listed under /etc/securetty file i.e tty{0,1,2,….}. If you remember ‪PAM then /etc/securetty file can be used to control local root login on the system. But that is only for controlling “local” login. This file cannot be used to control SSH sessions for root or other non-privilege users.

Pseudo terminals are terminals or character devices which are created on the fly or on demand whenever you do a right-click open terminal on your desktop environment. These terminals are also created on the fly whenever you do SSH to some machine.

Here is a illustration for you to explain the concept.

Happy Learning.


Understanding Pseudo Terminals

Understanding Pseudo Terminals