2 .\" Copyright (c) 1989, 1990, 1993, 1994
3 .\" The Regents of the University of California. All rights reserved.
5 .\" This code is derived from software contributed to Berkeley by
6 .\" the Institute of Electrical and Electronics Engineers, Inc.
8 .\" Redistribution and use in source and binary forms, with or without
9 .\" modification, are permitted provided that the following conditions
11 .\" 1. Redistributions of source code must retain the above copyright
12 .\" notice, this list of conditions and the following disclaimer.
13 .\" 2. Redistributions in binary form must reproduce the above copyright
14 .\" notice, this list of conditions and the following disclaimer in the
15 .\" documentation and/or other materials provided with the distribution.
16 .\" 3. Neither the name of the University nor the names of its contributors
17 .\" may be used to endorse or promote products derived from this software
18 .\" without specific prior written permission.
20 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 .\" @(#)chmod.1 8.4 (Berkeley) 3/31/94
43 .Op Fl R Op Fl H | L | P
49 utility modifies the file mode bits of the listed files
54 The options are as follows:
55 .Bl -tag -width indent
57 Do not display a diagnostic message if
59 could not modify the mode for
61 nor modify the exit status to reflect such failures.
65 option is specified, symbolic links on the command line are followed
66 and hence unaffected by the command.
67 (Symbolic links encountered during tree traversal are not followed.)
69 If the file is a symbolic link, change the mode of the link itself
70 rather than the file that the link points to.
74 option is specified, all symbolic links are followed.
78 option is specified, no symbolic links are followed.
81 Change the modes of the file hierarchies rooted in the files,
82 instead of just the files themselves.
83 Beware of unintentionally matching the
85 hard link to the parent directory when using wildcards like
90 to be verbose, showing filenames as the mode is modified.
93 flag is specified more than once, the old and new modes of the file
94 will also be printed, in both octal and symbolic notation.
102 options are ignored unless the
105 In addition, these options override each other and the
106 command's actions are determined by the last one specified.
116 then the current filename as well as the old and new modes are displayed.
118 Only the owner of a file or the super-user is permitted to change
123 Modes may be absolute or symbolic.
124 An absolute mode is an octal number constructed from the sum of
125 one or more of the following values:
127 .Bl -tag -width 6n -compact -offset indent
130 Executable files with this bit set
131 will run with effective uid set to the uid of the file owner.
132 Directories with this bit set will force all files and
133 sub-directories created in them to be owned by the directory owner
134 and not by the uid of the creating process, if the underlying file
135 system supports this feature: see
143 Executable files with this bit set
144 will run with effective gid set to the gid of the file owner.
154 Allow write by owner.
156 For files, allow execution by owner.
157 For directories, allow the owner to
158 search in the directory.
160 Allow read by group members.
162 Allow write by group members.
164 For files, allow execution by group members.
165 For directories, allow
166 group members to search in the directory.
168 Allow read by others.
170 Allow write by others.
172 For files, allow execution by others.
173 For directories allow others to
174 search in the directory.
177 For example, the absolute mode that permits read, write and execute by
178 the owner, read and execute by group members, read and execute by
179 others, and no set-uid or set-gid behaviour is 755
180 (400+200+100+040+010+004+001).
182 The symbolic mode is described by the following grammar:
183 .Bd -literal -offset indent
184 mode ::= clause [, clause ...]
185 clause ::= [who ...] [action ...] action
186 action ::= op [perm ...]
187 who ::= a | u | g | o
189 perm ::= r | s | t | w | x | X | u | g | o
194 symbols ``u'', ``g'', and ``o'' specify the user, group, and other parts
195 of the mode bits, respectively.
198 symbol ``a'' is equivalent to ``ugo''.
202 symbols represent the portions of the mode bits as follows:
204 .Bl -tag -width Ds -compact -offset indent
208 The set-user-ID-on-execution and set-group-ID-on-execution bits.
214 The execute/search bits.
216 The execute/search bits if the file is a directory or any of the
217 execute/search bits are set in the original (unmodified) mode.
220 symbol ``X'' are only meaningful in conjunction with the
222 symbol ``+'', and are ignored in all other cases.
224 The user permission bits in the original mode of the file.
226 The group permission bits in the original mode of the file.
228 The other permission bits in the original mode of the file.
233 symbols represent the operation performed, as follows:
236 If no value is supplied for
238 the ``+'' operation has no effect.
239 If no value is supplied for
241 each permission bit specified in
243 for which the corresponding bit in the file mode creation mask
247 Otherwise, the mode bits represented by the specified
253 If no value is supplied for
255 the ``\-'' operation has no effect.
256 If no value is supplied for
258 each permission bit specified in
260 for which the corresponding bit in the file mode creation mask
262 Otherwise, the mode bits represented by the specified
268 The mode bits specified by the
270 value are cleared, or, if no
272 value is specified, the owner, group
273 and other mode bits are cleared.
274 Then, if no value is supplied for
276 each permission bit specified in
278 for which the corresponding bit in the file mode creation mask
280 Otherwise, the mode bits represented by the specified
289 specifies one or more operations to be performed on the mode
290 bits, and each operation is applied to the mode bits in the
293 Operations upon the other permissions only (specified by the symbol
294 ``o'' by itself), in combination with the
296 symbols ``s'' or ``t'', are ignored.
298 The ``w'' permission on directories will permit file creation, relocation,
299 and copy into that directory.
300 Files created within the directory itself will inherit its group ID.
302 .Bl -tag -width "u=rwx,go=u-w" -compact
304 make a file readable by anyone and writable by the owner only.
307 deny write permission to group and others.
310 set the read and write permissions to the usual defaults, but
311 retain any execute permissions that are currently set.
314 make a directory or file searchable/executable by everyone if it is
315 already searchable/executable by anyone.
320 make a file readable/executable by everyone and writable by the owner only.
323 clear all mode bits for group and others.
326 set the group bits equal to the user bits, but clear the group write bit.
331 option is non-standard and its use in scripts is not recommended.
348 utility is expected to be
350 compatible with the exception of the
354 which is not included in that standard.
363 option for the naughty bits of a horse.