What is the 'chmod' command?

Chmod command is used to change file or directory access permission and is the most frequently used command in Unix. According to mode, the chmod command changes the permission of each given file.

The syntax of the chmod command is :

Chmod [options] mode filename.

Here in the above format, options could be :

-R : recursively change the permission of the file or directory.
-v : verbose, i.e. output a diagnostic for every file processed.
-c : report only when the change is made.
Etc.