chmod

Change file mode bits

chmod changes the file mode bits of each given file according to mode, which can be either a symbolic representation of changes to make, or an octal number representing the bit pattern for the new mode bits.

Octal note

A widely used, often shorter, form of calling chmod is by use of the octal notation. This is a combination of three numbers by which we can represent all combinations of access rights.

The following table shows the equivalent octal and symbolic notations:

r/w/x | binary | octal
 ---  |  000   |   0
 --x  |  001   |   1
 -w-  |  010   |   2
 -wx  |  011   |   3
 r--  |  100   |   4
 r-x  |  101   |   5
 rw-  |  110   |   6
 rwx  |  111   |   7