CHMOD(1)                             BSD                              CHMOD(1)



NAME
     chmod - change mode

SYNOPSIS
     chmod [ -Rf ] mode file ...

DESCRIPTION
     chmod changes the mode of each named file 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 (the sticky bit is not supported by Domain/OS
                    BSD)
          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 following form:

          [ who ] op permission [ op permission ]

     who is a combination of the letters u (for user's  permissions), g
     (group), and o (other).  The letter a stands for all, or ugo.  If you
     omit who, the default is a, but the setting of the creation mask is taken
     into account.  See umask(2) for further details on this.

     op can be + to add permission to the file's mode, - to take away
     permission, or = to assign permission absolutely (all other bits are
     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).  The letters u, g, or o indicate that permission is to be taken
     from the current mode. Omitting permission is useful only with an equal
     sign (=) to take away all permissions.

     You can specify multiple symbolic modes separated by commas.  Operations
     are performed in the order specified.  The letter s is useful only with u
     or g.

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

OPTIONS
     -R        When you specify -R, chmod recursively descends its directory
               arguments, setting the mode for each file as described above.
               When symbolic links are encountered, their mode is not changed
               and they are not traversed.

     -f        When you specify this option, chmod does not complain if it
               fails to change the mode on a file.

EXAMPLES
     To deny others write permission to file1, enter the following command:

          chmod o-w file1

     To make file1 executable, enter the following command:

          chmod +x file1

     To make file1 executable by all if it's executable by anyone, enter the
     following command:

          chmod +X file1

     To allow the owner of file1 read, write, and execute permissions to that
     file, but allow the group and others only read permission, enter the
     following command:

          chmod 744 file1

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