setfacl(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | CONFORMANCE TO POSIX 1003.1e DRAFT STANDARD 17 | AUTHOR | SEE ALSO | COLOPHON

SETFACL(1)                Access Control Lists                SETFACL(1)

NAME         top

       setfacl - set file access control lists

SYNOPSIS         top

       setfacl [-bkndRLPvh] [{-m|-x} acl_spec] [{-M|-X} acl_file] file
       ...

       setfacl --restore=file

DESCRIPTION         top

       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.)

OPTIONS         top

       -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).

EXAMPLES         top

       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         top

       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         top

       Andreas Gruenbacher, <andreas.gruenbacher@gmail.com>.

       Please send your bug reports, suggested features and comments to
       the above address.

SEE ALSO         top

       getfacl(1), chmod(1), umask(1), acl(5)

COLOPHON         top

       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 2021-04-01.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2021-03-16.)  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)

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