Can you explain what an Access Control List (ACL) means in the Linux operating system and how it is used to manage access?

Access Control List (ACL) in Linux is an advanced access rights management mechanism for files and directories, which complements the standard permissions (rwx for owner, group, and others).

ACL allows setting access rights for specific users and groups, going beyond the standard model. This is useful when more flexible access control is needed, for example, giving different users different rights to the same file.

To work with ACLs in Linux, the commands getfacl (view) and setfacl (set) are used. Example:

# View ACL of a file
getfacl example.txt

# Add read permission for user user1
setfacl -m u:user1:r-- example.txt

Thus, ACL extends access management capabilities, allowing detailed configuration of rights for individual users and groups.