1SETFACL(1)                   Access Control Lists                   SETFACL(1)
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NAME

6       setfacl - set file access control lists
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SYNOPSIS

9       setfacl [-bkndRLPvh] [{-m|-x} acl_spec] [{-M|-X} acl_file] file ...
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11       setfacl --restore=file
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DESCRIPTION

15       This utility sets Access Control Lists (ACLs) of files and directories.
16       On the command line, a sequence of commands is followed by  a  sequence
17       of  files  (which  in  turn can be followed by another sequence of com‐
18       mands, ...).
19
20       The -m and -x options expect an ACL on the command line.  Multiple  ACL
21       entries  are separated by comma characters (`,'). The -M and -X options
22       read an ACL from a file or from standard input. The ACL entry format is
23       described in Section ACL ENTRIES.
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25       The  --set and --set-file options set the ACL of a file or a directory.
26       The previous ACL is replaced.  ACL  entries  for  this  operation  must
27       include permissions.
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29       The  -m  (--modify)  and -M (--modify-file) options modify the ACL of a
30       file or directory.  ACL entries for this operation must include permis‐
31       sions.
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33       The -x (--remove) and -X (--remove-file) options remove ACL entries. It
34       is not an error to remove an entry which  does  not  exist.   Only  ACL
35       entries  without  the  perms  field  are accepted as parameters, unless
36       POSIXLY_CORRECT is defined.
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38       When reading from files using the -M and -X  options,  setfacl  accepts
39       the  output getfacl produces.  There is at most one ACL entry per line.
40       After a Pound sign (`#'), everything up to  the  end  of  the  line  is
41       treated as a comment.
42
43       If  setfacl  is used on a file system which does not support ACLs, set‐
44       facl operates on the file mode permission bits. If the ACL does not fit
45       completely  in the permission bits, setfacl modifies the file mode per‐
46       mission bits to reflect the ACL as closely as possible, writes an error
47       message to standard error, and returns with an exit status greater than
48       0.
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50
51   PERMISSIONS
52       The file owner and processes capable  of  CAP_FOWNER  are  granted  the
53       right  to  modify  ACLs of a file. This is analogous to the permissions
54       required for accessing the file mode. (On current Linux  systems,  root
55       is the only user with the CAP_FOWNER capability.)
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OPTIONS

59       -b, --remove-all
60           Remove all extended ACL entries. The base ACL entries of the owner,
61           group and others are retained.
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63       -k, --remove-default
64           Remove the Default ACL. If no Default ACL exists, no  warnings  are
65           issued.
66
67       -n, --no-mask
68           Do  not recalculate the effective rights mask. The default behavior
69           of setfacl is to recalculate the ACL  mask  entry,  unless  a  mask
70           entry  was explicitly given.  The mask entry is set to the union of
71           all permissions of the owning group, and all named user  and  group
72           entries.  (These  are  exactly  the  entries  affected  by the mask
73           entry).
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75       --mask
76           Do recalculate the effective rights mask, even if an ACL mask entry
77           was explicitly given. (See the -n option.)
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79       -d, --default
80           All operations apply to the Default ACL. Regular ACL entries in the
81           input set are promoted to Default ACL entries. Default ACL  entries
82           in  the  input set are discarded. (A warning is issued if that hap‐
83           pens).
84
85       --restore=file
86           Restore a permission backup created by `getfacl -R' or similar. All
87           permissions of a complete directory subtree are restored using this
88           mechanism. If the input contains owner comments or group  comments,
89           setfacl  attempts  to  restore  the  owner and owning group. If the
90           input contains flags comments (which define the setuid, setgid, and
91           sticky bits), setfacl sets those three bits accordingly; otherwise,
92           it clears them. This option cannot  be  mixed  with  other  options
93           except `--test'.
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95       --test
96           Test mode. Instead of changing the ACLs of any files, the resulting
97           ACLs are listed.
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99       -R, --recursive
100           Apply operations to all files  and  directories  recursively.  This
101           option cannot be mixed with `--restore'.
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103       -L, --logical
104           Logical  walk,  follow  symbolic  links to directories. The default
105           behavior is to follow symbolic link arguments,  and  skip  symbolic
106           links encountered in subdirectories.  Only effective in combination
107           with -R.  This option cannot be mixed with `--restore'.
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109       -P, --physical
110           Physical walk, do not follow symbolic links to  directories.   This
111           also  skips symbolic link arguments.  Only effective in combination
112           with -R.  This option cannot be mixed with `--restore'.
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114       -v, --version
115           Print the version of setfacl and exit.
116
117       -h, --help
118           Print help explaining the command line options.
119
120       --  End of command line options. All remaining  parameters  are  inter‐
121           preted as file names, even if they start with a dash.
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123       -   If  the  file name parameter is a single dash, setfacl reads a list
124           of files from standard input.
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126
127   ACL ENTRIES
128       The setfacl utility recognizes the following ACL entry formats  (blanks
129       inserted for clarity):
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132       [d[efault]:] [u[ser]:]uid [:perms]
133              Permissions  of  a  named user. Permissions of the file owner if
134              uid is empty.
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136       [d[efault]:] g[roup]:gid [:perms]
137              Permissions of a named group. Permissions of the owning group if
138              gid is empty.
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140       [d[efault]:] m[ask][:] [:perms]
141              Effective rights mask
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143       [d[efault]:] o[ther][:] [:perms]
144              Permissions of others.
145
146       Whitespace between delimiter characters and non-delimiter characters is
147       ignored.
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149       Proper ACL entries including permissions are used  in  modify  and  set
150       operations.  (options  -m,  -M, --set and --set-file).  Entries without
151       the perms field are used for deletion of entries (options -x and -X).
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153       For uid and gid you can specify either a name or a  number.   Character
154       literals  may  be  specified  with  a backslash followed by the 3-digit
155       octal digits corresponding to the ASCII code for the  character  (e.g.,
156       \101  for 'A').  If the name contains a literal backslash followed by 3
157       digits, the backslash must be escaped (i.e., \\).
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159       The perms field is a combination of characters that indicate  the  read
160       (r),  write (w), execute (x) permissions.  Dash characters in the perms
161       field (-) are ignored.  The character X stands for the execute  permis‐
162       sion  if  the file is a directory or already has execute permission for
163       some user.  Alternatively, the perms field can define  the  permissions
164       numerically, as a bit-wise combination of read (4), write (2), and exe‐
165       cute (1).  Zero perms fields or  perms  fields  that  only  consist  of
166       dashes indicate no permissions.
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168   AUTOMATICALLY CREATED ENTRIES
169       Initially,  files  and  directories  contain  only  the  three base ACL
170       entries for the owner, the group, and others. There are some rules that
171       need to be satisfied in order for an ACL to be valid:
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173       *   The three base entries cannot be removed. There must be exactly one
174           entry of each of these base entry types.
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176       *   Whenever an ACL contains named user entries or named group objects,
177           it must also contain an effective rights mask.
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179       *   Whenever an ACL contains any Default ACL entries, the three Default
180           ACL base entries (default owner, default group, and default others)
181           must also exist.
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183       *   Whenever  a  Default ACL contains named user entries or named group
184           objects, it must also contain a default effective rights mask.
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186       To help the user ensure  these  rules,  setfacl  creates  entries  from
187       existing entries under the following conditions:
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189       *   If  an  ACL contains named user or named group entries, and no mask
190           entry exists, a mask entry containing the same permissions  as  the
191           group  entry is created. Unless the -n option is given, the permis‐
192           sions of the mask entry are further adjusted to include  the  union
193           of  all  permissions affected by the mask entry. (See the -n option
194           description).
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196       *   If a Default ACL entry is created, and the Default ACL contains  no
197           owner, owning group, or others entry, a copy of the ACL owner, own‐
198           ing group, or others entry is added to the Default ACL.
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200       *   If a Default  ACL  contains  named  user  entries  or  named  group
201           entries, and no mask entry exists, a mask entry containing the same
202           permissions as the default Default  ACL's  group  entry  is  added.
203           Unless  the  -n  option is given, the permissions of the mask entry
204           are further adjusted  to  include  the  union  of  all  permissions
205           affected by the mask entry. (See the -n option description).
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EXAMPLES

208       Granting an additional user read access
209              setfacl -m u:lisa:r file
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211       Revoking  write  access  from all groups and all named users (using the
212       effective rights mask)
213              setfacl -m m::rx file
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215       Removing a named group entry from a file's ACL
216              setfacl -x g:staff file
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218       Copying the ACL of one file to another
219              getfacl file1 | setfacl --set-file=- file2
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221       Copying the access ACL into the Default ACL
222              getfacl --access dir | setfacl -d -M- dir
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CONFORMANCE TO POSIX 1003.1e DRAFT STANDARD 17

225       If the environment variable POSIXLY_CORRECT  is  defined,  the  default
226       behavior  of  setfacl  changes as follows: All non-standard options are
227       disabled.  The ``default:'' prefix is disabled.  The -x and -X  options
228       also accept permission fields (and ignore them).
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AUTHOR

231       Andreas Gruenbacher, <a.gruenbacher@bestbits.at>.
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233       Please  send  your  bug reports, suggested features and comments to the
234       above address.
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SEE ALSO

237       getfacl(1), chmod(1), umask(1), acl(5)
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241May 2000                      ACL File Utilities                    SETFACL(1)
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