plan9 man page for chmod

CHMOD(1)						      General Commands Manual							  CHMOD(1)

NAME
       chmod - change mode

SYNOPSIS
       chmod mode file ...

DESCRIPTION
       The  mode  of each named file is changed according to mode, which may be an octal number or a symbolic change to the existing mode.  A mode
       is an octal number constructed from the OR of the following modes.

       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

       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.

       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), a (append only), and l (exclusive access).

       Only the owner of a file or the group leader of its group may change the file's mode.

SOURCE
       /sys/src/cmd/chmod.c

SEE ALSO
       ls(1), stat(2), stat(5)

																	  CHMOD(1)