remove-shell

remove-shell username

username
    The login name of the user whose shell is to be disabled.

The command "remove-shell" is not a standard, universally available Linux command found in most distributions. Instead, the operation of "removing" or disabling a user's login shell is typically performed by changing their assigned shell to a non-interactive one, such as /sbin/nologin or /bin/false.

A hypothetical "remove-shell" command would serve to prevent a specified user from logging in interactively via a shell. This is a common security practice for system accounts, service accounts, or temporarily locking out a user without deleting their account. By setting a user's shell to a program that immediately exits (like nologin), it ensures that direct shell access is denied while other services (e.g., mail, FTP if configured) associated with the user account might still function.

The primary method for achieving this in standard Linux environments is using the chsh (change shell) command or by directly editing the /etc/passwd file (though direct editing is discouraged for safety). Therefore, any "remove-shell" command encountered would likely be a custom script or utility specific to a particular system's administration practices.

This command is not part of standard Linux utilities. The functionality it describes is typically achieved via chsh.
Disabling a user's shell prevents all interactive logins for that user. Ensure this is the intended action, as it will affect SSH, console logins, etc.
It does not delete the user account or their home directory. It only restricts shell access.
Improper use, especially with administrative accounts, can lead to system lockout if not carefully managed.

The most common and recommended way to achieve the effect of 'removing' a user's shell is using the chsh command. For example:
chsh -s /sbin/nologin username
This sets the user's shell to /sbin/nologin, which immediately exits upon login attempt, effectively disabling interactive access.

You can check a user's assigned shell using getent passwd:
getent passwd username
The last field of the output will show the user's current shell.

The concept of disabling a user's interactive shell access dates back to early Unix systems for managing service accounts or restricting login capabilities. While a specific "remove-shell" command is not historically standard, the underlying methods (modifying /etc/passwd or using utilities like chsh) have been integral to user management in Unix-like operating systems since their inception. The introduction of specific non-login shells like /sbin/nologin provided a standardized and robust way to achieve this security objective, evolving alongside user management tools.

chsh(1), userdel(8), passwd(5), getent(1)