chmod mode file... 
chmod [augo][+-=][rwx]	file...

A mode can be numerically constructed from the INCLUSIVE OR of the following VALUES:

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.

The op field can be:

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

The permission field is any combination of the letters r (read), w (write), and x (execute).

Caveats

• The #r format for expressing integer values is not recognized.

• The standard format for octal numbers (8r...) is not recognized.

See Also

ls - list contents of directory

stat, fstat, fwstat, wstat - get and put file status in Chapter 8