Control Access to Files with ACL - RHCSA (RH134).pdf

Slides on how to control access to files with ACL - Part of RHCSA (RH134) syllabus

1. Controlling Access to Files
with ACL

2. ACL
●ACL stands for Access Control
List
●Determines who can access
specific resources
●ACL enhances file system
permissions flexibility
●Designed to complement UNIX
file permissions
●Assigning write permission with
ACL prevents file deletion

3. Remove and assign ACL permissions
●setfacl: To set or modify the Access Control List (ACL) of a file or
directory

●getfacl: To display the current Access Control List (ACL) of a file
or directory

4. ●-m: Modify the ACL of a file or directory
●-x: Remove an ACL entry from a file or directory
●-b: Remove all ACL entries
●-k: Remove the default ACL
●-R: Apply ACL changes recursively
●-d: Set default ACLs for new files and directories
Options for setting ACL permissions

5. File Permission
Note - When you assign ACL permissions to a file or directory, it appends a
"+" symbol to the permission.

6. ACL commands
1.Sets Access Control List permissions for user
Command : setfacl -m u:<username>:<permissions> <filename>

7. 2. Sets Access Control List permissions for group
Command : setfacl -m g:<groupname>:<permissions> <filename>

8. 3. Retrieves Access Control List permissions
Command : getfacl <filename>

9. 4. Remove all entries
Command : setfacl -b <filename>

10. 5. Remove ACL permissions for specific user
Command : setfacl -x u:<username> <filename>

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