CHMOD(1)            UNIX Programmer's Manual             CHMOD(1)

NAME
     chmod - change mode

SYNTAX
     chmod mode file ...

DESCRIPTION
     The mode of each named file is changed according to _m_o_d_e,
     which may be absolute or symbolic.  An absolute _m_o_d_e 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 _c_h_m_o_d(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 _m_o_d_e has the form:

          [_w_h_o] _o_p _p_e_r_m_i_s_s_i_o_n [_o_p _p_e_r_m_i_s_s_i_o_n] ...

     The _w_h_o part is a combination of the letters u (for user's
     permissions), g (group) and o (other).  The letter a stands
     for ugo. If _w_h_o is omitted, the default is _a but the setting
     of the file creation mask (see _u_m_a_s_k(2)) is taken into
     account.

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

     _P_e_r_m_i_s_s_i_o_n is any combination of the letters r (read), w
     (write), x (execute), s (set owner or group id) and t (save
     text - sticky).  The `sticky' bit can only be set by the
     super-user (see _c_h_m_o_d(2)).  Letters u, g or o indicate that
     _p_e_r_m_i_s_s_i_o_n is to be taken from the current mode.  Omitting
     _p_e_r_m_i_s_s_i_o_n is only useful with '=' to take away all permis-
     sions.

     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.

Printed 5/16/83                                                 1

CHMOD(1)            UNIX Programmer's Manual             CHMOD(1)

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

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

Printed 5/16/83                                                 2