Change Mode

What Does Change Mode Mean?

Change mode (chmod) is a Unix operating system command used by administrators and programmers to set or change the access permissions of a file or directory. These settings determine the level of access to be granted to the given file or directory.

The chmod command was first used in ATT Unix 1 and is still in use today by Unix-like operating systems. It is also available as a C language library function in Unix.

Techopedia Explains Change Mode

The syntax for change mode is as follows:

chmod [OPTIONS]… MODE[,MODE]… FILENAME1 [,FILENAME2]…
chmod [OPTION]… OCTAL-MODE FILENAME1 [,FILENAME2]…
chmod [OPTION]… [REFERENCE] [OPERATOR] [MODES] FILENAME1 [,FILENAME2]..

The chmod command has the following options:

-R, –recursive: Changes the directories and files recursively
-v, –verbose: Displays a diagnostic report for every processed file
-c, –changes: Like verbose but displays only when there are actual changes
-f, –silent:Suppress error messages
–reference=RFILE: Use RFILE’s mode instead of MODE values

Permissions are granted as follows: a: All
o: Other
g: Group
r: Read
u: User
w: Write
x: Execute or run as a program