man > setfacl(1)

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 -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 in‐
       put. 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 pro‐
       duces.  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 mod‐
       ifies  the file mode permission bits to reflect the ACL as closely as possible, writes an er‐
       ror 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 re‐
           calculate 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  pro‐
           moted  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 com‐
           plete 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'.  If the file specified is '-', then it  will
           be read from standard input.

       --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 ef‐
           fective 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 speci‐
       fied 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 (de‐
           fault 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 fur‐
           ther adjusted to include the union of all permissions 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  dis‐
       abled.  The -x and -X options also accept permission fields (and ignore them).

AUTHOR
       Andreas Gruenbacher, <andreas.gruenbacher AT gmail.com>.

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

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

May 2000                                 ACL File Utilities                               SETFACL(1)