setfacl

setfacl is a command line tool used in Unix-like operating systems, such as Linux, to manage file system access control lists (ACLs). ACLs provide a more granular level of control over file and directory permissions than the traditional owner, group, and other permissions. It allows users to set access permissions for multiple users or groups.

The setfacl command allows users to modify existing ACLs or add new ones to files and directories. It provides flexibility in specifying permissions, including read, write, execute, and additional specific permissions like delete, append, and more.

With setfacl, users are able to grant or deny permissions to specific users or groups in a more nuanced way. It allows for setting default ACLs, which are automatically applied to newly created files and directories within a specified directory.

The tool supports both named users and groups, as well as numerical user and group identifiers. It can be used in conjunction with the getfacl command to view the existing ACLs of files and directories.

setfacl is a powerful and essential tool for system administrators and users who require fine-grained control over access permissions in Unix-like systems.