man(1) Manual page archive

     CHMOD(1)                                                 CHMOD(1)

          chmod - change mode

          chmod mode file ...

          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
          permissions), g (group) and o (other).  The letter a stands
          for ugo. If who is omitted, the default is a but the setting
          of the file creation mask (see umask(2)) is taken into

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

          Permission is any combination of the letters r (read), w
          (write), x (execute), 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.

          The first example denies write permission to others, the
          second makes a file executable:

               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.

     CHMOD(1)                                                 CHMOD(1)

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

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