icacls - Display or modify permission for files and folders using windows command prompt.

We can Display or modify Access Control Lists (ACLs) or permission for files and folders using windows command prompt too.Access Control Lists can be only applied to files stored on an NTFS formatted drive.

Each ACL specify which users (or groups of users) can read or edit the file. 
When a new file is created it normally inherits ACL's from the folder where it was created.

For Vista and above use icacls.
NOTE: Cacls is now deprecated, please use Icacls.

SYNTAX :- 

CACLS filename [/T] [/M] [/L] [/S[:SDDL]] [/E] [/C] [/G user:perm] [/R user [...]] [/P user:perm [...]] [/D user [...]]

  filename : Displays ACLs.
  /T : Changes ACLs of specified files in the current directory and all subdirectories.
  /L : Work on the Symbolic Link itself versus the target
  /M : Changes ACLs of volumes mounted to a directory
  /S : Displays the SDDL string for the DACL.
  /S : SDDL Replaces the ACLs with those specified in the SDDL string (not valid with /E, /G, /R, /P, or /D).
  /E : Edit ACL instead of replacing it.
  /C : Continue on access denied errors.
  /G : user:perm Grant specified user access rights.

•  Perm can be : R Read
•  W : Write
•  C  : Change (write)
•  F : Full control

  /R : user Revoke specified user's access rights (only valid with /E).
  /P : user:perm Replace specified user's access rights.

•  Perm can be: N None
•  R Read
•  W Write
•  C Change (write)
•  F Full control

 /D : user Deny specified user access.

 Wildcards can be used to specify more than one file in a command.
 You can specify more than one user in a command.

 Abbreviations :-
 CI - Container Inherit : The ACE will be inherited by directories.
 OI - Object Inherit : The ACE will be inherited by files.
 IO - Inherit Only : The ACE does not apply to the current file/directory.
 ID - Inherited : The ACE was inherited from the parent directory's ACL. 

EXAMPLE :-

Give everyone read-only permission to a folder

C:\Users\lmntechnohub\Desktop>cacls Music /e /g Everyone:R
processed dir: C:\Users\lmntechnohub\Desktop\Music 

Remove everyone read-only permission to a folder

C:\Users\lmntechnohub\Desktop>cacls Music /e /R Everyone
processed dir: C:\Users\lmntechnohub\Desktop\Music