SETFACL(1) Access Control Lists SETFACL(1)
NAME
setfacl - set file access control lists
SYNOPSIS
setfacl [-bkndRLPvh] [{-m|-x} acl_spec] [{-M|-X} acl_file] file ...
setfacl --restore=file
DESCRIPTION
This utility sets Access Control Lists (ACLs) of files and directories. On the command line, a sequence of
commands is followed by a sequence of files (which in turn can be followed by another sequence of commands,
...).
The options -m, and -x expect an ACL on the command line. Multiple ACL entries are separated by comma charac‐
ters (`,'). The options -M, and -X read an ACL from a file or from standard input. The ACL entry format is
described in Section ACL ENTRIES.
The --set and --set-file options set the ACL of a file or a directory. The previous ACL is replaced. ACL
entries for this operation must include permissions.
The -m (--modify) and -M (--modify-file) options modify the ACL of a file or directory. ACL entries for this
operation must include permissions.
The -x (--remove) and -X (--remove-file) options remove ACL entries. It is not an error to remove an entry
which does not exist. Only ACL entries without the perms field are accepted as parameters, unless
POSIXLY_CORRECT is defined.
When reading from files using the -M, and -X options, setfacl accepts the output getfacl produces. There is
at most one ACL entry per line. After a Pound sign (`#'), everything up to the end of the line is treated as a
comment.
If setfacl is used on a file system which does not support ACLs, setfacl operates on the file mode permission
bits. If the ACL does not fit completely in the permission bits, setfacl modifies the file mode permission
bits to reflect the ACL as closely as possible, writes an error message to standard error, and returns with an
exit status greater than 0.
PERMISSIONS
The file owner and processes capable of CAP_FOWNER are granted the right to modify ACLs of a file. This is
analogous to the permissions required for accessing the file mode. (On current Linux systems, root is the only
user with the CAP_FOWNER capability.)
OPTIONS
-b, --remove-all
Remove all extended ACL entries. The base ACL entries of the owner, group and others are retained.
-k, --remove-default
Remove the Default ACL. If no Default ACL exists, no warnings are issued.
-n, --no-mask
Do not recalculate the effective rights mask. The default behavior of setfacl is to recalculate the ACL
mask entry, unless a mask entry was explicitly given. The mask entry is set to the union of all permis‐
sions of the owning group, and all named user and group entries. (These are exactly the entries affected
by the mask entry).
attempts to restore the owner and owning group. If the input contains flags comments (which define the
setuid, setgid, and sticky bits), setfacl sets those three bits accordingly; otherwise, it clears them.
This option cannot be mixed with other options except `--test'.
--test
Test mode. Instead of changing the ACLs of any files, the resulting ACLs are listed.
-R, --recursive
Apply operations to all files and directories recursively. This option cannot be mixed with `--restore'.
-L, --logical
Logical walk, follow symbolic links to directories. The default behavior is to follow symbolic link argu‐
ments, and skip symbolic links encountered in subdirectories. Only effective in combination with -R.
This option cannot be mixed with `--restore'.
-P, --physical
Physical walk, do not follow symbolic links to directories. This also skips symbolic link arguments.
Only effective in combination with -R. This option cannot be mixed with `--restore'.
-v, --version
Print the version of setfacl and exit.
-h, --help
Print help explaining the command line options.
-- End of command line options. All remaining parameters are interpreted as file names, even if they start
with a dash.
- If the file name parameter is a single dash, setfacl reads a list of files from standard input.
ACL ENTRIES
The setfacl utility recognizes the following ACL entry formats (blanks inserted for clarity):
[d[efault]:] [u[ser]:]uid [:perms]
Permissions of a named user. Permissions of the file owner if uid is empty.
[d[efault]:] g[roup]:gid [:perms]
Permissions of a named group. Permissions of the owning group if gid is empty.
[d[efault]:] m[ask][:] [:perms]
Effective rights mask
[d[efault]:] o[ther][:] [:perms]
Permissions of others.
Whitespace between delimiter characters and non-delimiter characters is ignored.
Proper ACL entries including permissions are used in modify and set operations. (options -m, -M, --set and
--set-file). Entries without the perms field are used for deletion of entries (options -x and -X).
For uid and gid you can specify either a name or a number.
rights mask.
* Whenever an ACL contains any Default ACL entries, the three Default ACL base entries (default owner,
default group, and default others) must also exist.
* Whenever a Default ACL contains named user entries or named group objects, it must also contain a default
effective rights mask.
To help the user ensure these rules, setfacl creates entries from existing entries under the following condi‐
tions:
* If an ACL contains named user or named group entries, and no mask entry exists, a mask entry containing
the same permissions as the group entry is created. Unless the -n option is given, the permissions of the
mask entry are further adjusted to include the union of all permissions affected by the mask entry. (See
the -n option description).
* If a Default ACL entry is created, and the Default ACL contains no owner, owning group, or others entry, a
copy of the ACL owner, owning group, or others entry is added to the Default ACL.
* If a Default ACL contains named user entries or named group entries, and no mask entry exists, a mask
entry containing the same permissions as the default Default ACL's group entry is added. Unless the -n
option is given, the permissions of the mask entry are further adjusted to include the union of all per‐
missions affected by the mask entry. (See the -n option description).
EXAMPLES
Granting an additional user read access
setfacl -m u:lisa:r file
Revoking write access from all groups and all named users (using the effective rights mask)
setfacl -m m::rx file
Removing a named group entry from a file's ACL
setfacl -x g:staff file
Copying the ACL of one file to another
getfacl file1 | setfacl --set-file=- file2
Copying the access ACL into the Default ACL
getfacl --access dir | setfacl -d -M- dir
CONFORMANCE TO POSIX 1003.1e DRAFT STANDARD 17
If the environment variable POSIXLY_CORRECT is defined, the default behavior of setfacl changes as follows:
All non-standard options are disabled. The ``default:'' prefix is disabled. The -x and -X options also
accept permission fields (and ignore them).
AUTHOR
Andreas Gruenbacher, <[email protected]>.
Please send your bug reports, suggested features and comments to the above address.
SEE ALSO
getfacl(1), chmod(1), umask(1), acl(5)
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