setfacl:tldr:79c00

The command "setfacl -x u:${username} ${file}" is used to remove an access control entry (ACE) for a specific user from a file or directory.

Here is a breakdown of the command:

• "setfacl" is a command-line utility used to manage file system access control lists (ACLs). ACLs are a way to define permissions and access control for files and directories beyond traditional owner-group-others permissions.

• "-x" is an option used to specify the removal of an ACE.

• "u:${username}" is the user identifier (UID) or username of the user whose ACE needs to be removed. The "${username}" variable should be replaced with the actual username.

• "${file}" represents the file or directory for which the ACE needs to be removed. The "${file}" variable should be replaced with the actual file path.

By executing this command, the specified user's ACE will be removed from the file or directory, revoking their access rights defined by that ACE.