4.3BSD - /usr/man/cat1/chmod.0

CHMOD(1)                                                              CHMOD(1)


NAME
       chmod - change mode

SYNOPSIS
       chmod [ -Rf ] mode file ...

DESCRIPTION
       The  mode of each named file is changed according to mode, which may be
       absolute or symbolic.  An absolute mode is an octal number  constructed
       from the OR of the following modes:

       4000      set user ID on execution
       2000      set group ID on execution
       1000      sticky bit, see chmod(2)
       0400      read by owner
       0200      write by owner
       0100      execute (search in directory) by owner
       0070      read, write, execute (search) by group
       0007      read, write, execute (search) by others

       A symbolic mode has the form:

              [who] op permission [op permission] ...

       The  who  part  is  a  combination of the letters u (for user’s permis‐
       sions), g (group) and o (other).  The letter a stands for all, or  ugo.
       If  who  is  omitted, the default is a but the setting of the file cre‐
       ation mask (see umask(2)) is taken into account.

       Op can be + to add permission to the file’s mode, - to take  away  per���
       mission  and  = to assign permission absolutely (all other bits will be
       reset).

       Permission is any combination of the letters r  (read),  w  (write),  x
       (execute),  X  (set  execute  only if file is a directory or some other
       execute bit is set), s (set owner or group  id)  and  t  (save  text  -
       sticky).   Letters  u,  g, or o indicate that permission is to be taken
       from the current mode.  Omitting permission is only useful  with  =  to
       take away all permissions.

       When  the  -R option is given, chmod recursively descends its directory
       arguments setting the mode for each file as described above.  When sym‐
       bolic links are encountered, their mode is not changed and they are not
       traversed.

       If the -f option is given, chmod will  not  complain  if  it  fails  to
       change the mode on a file.

EXAMPLES
       The first example denies write permission to others, the second makes a
       file executable by all if it is executable by anyone:

              chmod o-w file
              chmod +X file

       Multiple symbolic modes separated by commas may be  given.   Operations
       are performed in the order specified.  The letter s is only useful with
       u or g.

       Only the owner of a file (or the super-user) may change its mode.

SEE ALSO
       ls(1), chmod(2), stat(2), umask(2), chown(8)


7th Edition                      May 22, 1986                         CHMOD(1)