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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | CONFORMANCE TO POSIX 1003.1e DRAFT STANDARD 17 | AUTHOR | SEE ALSO | COLOPHON |
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SETFACL(1) Access Control Lists SETFACL(1)
setfacl - set file access control lists
setfacl [-bkndRLPvh] [{-m|-x} acl_spec] [{-M|-X} acl_file] file ...
setfacl --restore=file
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 -m and -x options expect an ACL on the command line. Multiple ACL
entries are separated by comma characters (`,'). The -M and -X
options 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.)
-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 permissions of the owning group, and all named user
and group entries. (These are exactly the entries affected by the
mask entry).
--mask
Do recalculate the effective rights mask, even if an ACL mask
entry was explicitly given. (See the -n option.)
-d, --default
All operations apply to the Default ACL. Regular ACL entries in
the input set are promoted to Default ACL entries. Default ACL
entries in the input set are discarded. (A warning is issued if
that happens).
--restore=file
Restore a permission backup created by `getfacl -R' or similar.
All permissions of a complete directory subtree are restored
using this mechanism. If the input contains owner comments or
group comments, setfacl 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 arguments, 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. Character
literals may be specified with a backslash followed by the 3-digit
octal digits corresponding to the ASCII code for the character (e.g.,
\101 for 'A'). If the name contains a literal backslash followed by
3 digits, the backslash must be escaped (i.e., \\).
The perms field is a combination of characters that indicate the read
(r), write (w), execute (x) permissions. Dash characters in the
perms field (-) are ignored. The character X stands for the execute
permission if the file is a directory or already has execute
permission for some user. Alternatively, the perms field can define
the permissions numerically, as a bit-wise combination of read (4),
write (2), and execute (1). Zero perms fields or perms fields that
only consist of dashes indicate no permissions.
AUTOMATICALLY CREATED ENTRIES
Initially, files and directories contain only the three base ACL
entries for the owner, the group, and others. There are some rules
that need to be satisfied in order for an ACL to be valid:
* The three base entries cannot be removed. There must be exactly
one entry of each of these base entry types.
* Whenever an ACL contains named user entries or named group
objects, it must also contain an effective 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 conditions:
* 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
permissions affected by the mask entry. (See the -n option
description).
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
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).
Andreas Gruenbacher, <a.gruenbacher@bestbits.at>.
Please send your bug reports, suggested features and comments to the
above address.
getfacl(1), chmod(1), umask(1), acl(5)
This page is part of the acl (manipulating access control lists)
project. Information about the project can be found at
⟨http://savannah.nongnu.org/projects/acl⟩. If you have a bug report
for this manual page, see
⟨http://savannah.nongnu.org/bugs/?group=acl⟩. This page was obtained
from the project's upstream Git repository
⟨git://git.savannah.nongnu.org/acl.git⟩ on 2018-02-02. (At that
time, the date of the most recent commit that was found in the repos‐
itory was 2018-01-21.) If you discover any rendering problems in
this HTML version of the page, or you believe there is a better or
more up-to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not part
of the original manual page), send a mail to man-pages@man7.org
May 2000 ACL File Utilities SETFACL(1)
Pages that refer to this page: chacl(1), getfacl(1), nfs4_setfacl(1), tmpfiles.d(5), systemd-journald.service(8)
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