1CHMOD(1)                    General Commands Manual                   CHMOD(1)
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NAME

6       chmod - change mode
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SYNOPSIS

9       chmod [ -Rf ] mode file ...
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DESCRIPTION

12       The  mode of each named file is changed according to mode, which may be
13       absolute or symbolic.  An absolute mode is an octal number  constructed
14       from the OR of the following modes:
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16       4000      set user ID on execution
17       2000      set group ID on execution
18       1000      sticky bit, see chmod(2)
19       0400      read by owner
20       0200      write by owner
21       0100      execute (search in directory) by owner
22       0070      read, write, execute (search) by group
23       0007      read, write, execute (search) by others
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25       A symbolic mode has the form:
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27              [who] op permission [op permission] ...
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29       The  who  part  is  a  combination of the letters u (for user's permis‐
30       sions), g (group) and o (other).  The letter a stands for all, or  ugo.
31       If  who  is  omitted, the default is a but the setting of the file cre‐
32       ation mask (see umask(2)) is taken into account.
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34       Op can be + to add permission to the file's mode, - to take  away  per‐
35       mission  and  = to assign permission absolutely (all other bits will be
36       reset).
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38       Permission is any combination of the letters r  (read),  w  (write),  x
39       (execute),  X  (set  execute  only if file is a directory or some other
40       execute bit is set), s (set owner or group  id)  and  t  (save  text  -
41       sticky).   Letters  u,  g, or o indicate that permission is to be taken
42       from the current mode.  Omitting permission is only useful  with  =  to
43       take away all permissions.
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45       When  the  -R option is given, chmod recursively descends its directory
46       arguments setting the mode for each file as described above.  When sym‐
47       bolic links are encountered, their mode is not changed and they are not
48       traversed.
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50       If the -f option is given, chmod will  not  complain  if  it  fails  to
51       change the mode on a file.
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EXAMPLES

54       The first example denies write permission to others, the second makes a
55       file executable by all if it is executable by anyone:
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57              chmod o-w file
58              chmod +X file
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60       Multiple symbolic modes separated by commas may be  given.   Operations
61       are performed in the order specified.  The letter s is only useful with
62       u or g.
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64       Only the owner of a file (or the super-user) may change its mode.
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SEE ALSO

67       ls(1), chmod(2), stat(2), umask(2), chown(8)
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717th Edition                      May 22, 1986                         CHMOD(1)
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