lppasswd

lppasswd [-g group] [-a] [-d user] [-h server] [user]

-a
    Add a new user to the password file.

-d user
    Delete a user from the password file.

-g group
    Add user to named group.

-h server
    Specify the CUPS server to use. Defaults to the local server.

user
    The username to add or modify. If not specified with -d, it prompts for a password.

The lppasswd command allows users to add, modify, or delete passwords for users allowed to use certain printers managed by the CUPS printing system.
It primarily manipulates the password file used for authentication by CUPS print queues which require username/password authentication.
Specifically, it stores encrypted passwords in a CUPS-specific format.
This command is most useful in environments where print queues are configured to require authentication for printing or management tasks. It interacts directly with the CUPS configuration files to manage user credentials, therefore root access or CUPS administrator privileges might be required for certain operations.
It is often used in conjunction with configuring print queues that have access control lists (ACLs) to restrict printer access to specific users or groups.

Passwords are stored in a CUPS-specific encrypted format.
This command modifies CUPS configuration files, so it might require root or CUPS administrator privileges. Incorrect usage can potentially lock users out of print queues that require authentication. The underlying method used to store the passwords changed over time.

CUPS uses the password stored in the file to authenticate users accessing restricted print queues. If the password does not match for a given user, the printing request may fail, or the management operations might be denied.

The lppasswd command is part of the CUPS (Common Unix Printing System) suite.
It was developed as a utility to manage user passwords for print queues requiring authentication within the CUPS environment.
Its usage has evolved with CUPS, adapting to changes in authentication methods and security practices.

lpadmin(8), lp(1), cupsd(8)