Absolute mode

An absolute mode is particular using octal numbers chmod nnnn file...

where

n is a number from 0 to 7.

For directories, files are established with BSD semantics for propagation of the group ID. Within these files, option and subdirectories created in the directory inherit the group ID of the directory, rather than in which of the current procedure. It might be cleared only through using symbolic mode.

Options

The given options are supported:

-f         -    Forces the change, chmod will not complain if it fails to modify the mode of a file

-R        -    Recursively descends by directory arguments, setting the mode for each file as   elaborate above

Whenever symbolic connects are encountered, the   mode of the target file is modified, but no recursion takes place

Let consider the following examples

1. Deny execute permission to everyone:

# chmod a-x filename

2. Permits only read permission to everyone:

# chmod 444 filename

3. Make a file readable and writable by the group and others:

# chmod go+rw filename

# chmod 066 filename