Linux -- setfacl

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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 ...

　　#注意參數的使用順序

       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 permis‐
       sions.

       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

 

  　　-m, --modify=acl 變更檔的存取控制清單
  　　-M, --modify-file=file 從檔案讀取存取控制列表條目更改
 　　 -x, --remove=acl 根據檔案中存取控制清單移除條目
 　　 -X, --remove-file=file 從檔案讀取存取控制列表條目並刪除


       -b, --remove-all
           Remove all extended ACL entries. The base ACL entries of the owner, group and others are retained.
　　　　#刪除所有的ACL參數

       -k, --remove-default
           Remove the Default ACL. If no Default ACL exists, no warnings are issued.
　　　　#刪除預設的ACL參數

      -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‘.

       -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.

 

       -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  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 permis‐
           sions 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 inclu de 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 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)



May 2000                                                         ACL File Utilities                                                      SETFACL(1)

Linux -- setfacl