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  characters  (`,').
       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.  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 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.

       The  perms  field is a combination of characters that indicate the permissions: read (r), write (w), execute (x), execute
       only if the file is a directory or already has execute permission for some user (X).  Alternatively, the perms field  can
       be an octal digit (0-7).

   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 per-
           missions  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 contain-
           ing the same permissions as the default Default ACL's group entry is added. Unless the -n option is given,  the  per-
           missions  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
       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-stan-
       dard  options  are  disabled.   The ``default:'' prefix is disabled.  The -x and -X options also accept permission fields
       (and ignore them).

AUTHOR
       Andreas Gruenbacher, <a.gruenbacherATbestbits.at>.

       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)