acl_valid - Linux


acl_valid is a command-line tool for validating Access Control Lists (ACLs) in various formats, such as NFS4 ACLs and POSIX ACLs. It ensures that ACLs conform to the specified standards and best practices.


acl_valid [options] [ACL-file]


  • -f, –file: Read ACLs from the specified file.
  • -d, –directory: Validate ACLs of files and directories within the given directory.
  • -r, –recursive: Recursively validate ACLs in nested directories.
  • -n, –no-details: Suppress detailed error messages.
  • -q, –quiet: Suppress all output.
  • -h, –help: Display help and usage information.


Validate ACLs from a file:

acl_valid -f acl-file.txt

Validate ACLs of a directory recursively:

acl_valid -rd /path/to/directory

Suppress detailed error messages:

acl_valid -n /path/to/acl.txt

Common Issues

  • Nullified ACLs:

    • Problem: ACLs are mistakenly nullified during validation due to improper formatting or invalid entries.
    • Solution: Review the ACLs carefully for any syntax errors or invalid permissions.
  • Permission Errors:

    • Problem: acl_valid may report permission errors if the user does not have sufficient privileges to access the ACLs being validated.
    • Solution: Ensure that the user has read permissions for the ACL-related files or directories.


acl_valid can be used in conjunction with other commands for advanced ACL management tasks:

  • Restore ACLs:
    • acl_valid can be used to validate ACLs before restoring them from a backup using the aclrestore command.

Related Commands

  • acl
  • getfacl
  • setfacl
  • restorecon