rbash:tldr:73930

rbash is a restricted version of the Bash (Bourne-again shell) command interpreter. It is designed to provide limited access to the shell environment for certain users, giving them restricted capabilities and preventing certain actions or commands that could pose a security risk.

When a user is assigned rbash as their default shell, they have limited access to the system and are restricted from performing various actions such as changing directories (except for the directory specified by the HOME environment variable), setting environment variables, or executing commands outside the defined restricted shell environment.

rbash provides an added layer of security for users with restricted access, preventing them from executing potentially dangerous commands. However, it is important to note that rbash is not a foolproof security measure and should not be solely relied upon for securing a system. Additional security measures, such as proper user permissions, should still be implemented to ensure overall system security.