acl_calc_mask - Linux
Overview
acl_calc_mask is a command-line tool used to calculate the Access Control List (ACL) mask for a given set of permissions. It finds applications in scenarios involving ACL management and privilege assignment, particularly within the Linux environment.
Syntax
acl_calc_mask [-u] [-g] [-o] [-m <mask>] [<acl_spec> ...] <filename>
Options/Flags
| Option/Flag | Description |
|—|—|
| -u
| Calculate user-based ACL mask |
| -g
| Calculate group-based ACL mask |
| -o
| Calculate other/default ACL mask |
| -m <mask>
| Calculate mask based on specified octal mask |
Examples
Example 1: Calculate user-based ACL mask for permissions on a file
acl_calc_mask -u rw-r--r-- example.txt
Output:
0644
Example 2: Calculate group-based ACL mask for the same file
acl_calc_mask -g - rw-r--r-- example.txt
Output:
0055
Common Issues
- Insufficient permissions: Ensure the user running the command has sufficient permissions to read the ACL and modify files if necessary.
- Invalid ACL specification: Verify the syntax of the ACL specification entered.
- Non-existent file: Check if the specified filename exists before attempting to calculate the ACL mask.
Integration
acl_calc_mask can be integrated with other commands for more complex operations:
- Find files with specific ACL permissions: Use
find
to locate files with matching ACL permissions and calculate the ACL mask for each. - Set ACL permissions: Calculate the desired ACL mask using
acl_calc_mask
and then set permissions usingsetfacl
.
Related Commands
- getfacl
- restorecon
- setfacl