ACL - access control list

 Access control list (ACL):-

**************************

-> the main purpose of using the acl perm is to provide perticular user or group permissions on perticcular file or dir.

-> we have 2 types of identification

1) trival entry:-

*****************

if the perm of file/dir contains "+"  symbol after permissions thenn that file /dir is having ACL permissions

ex: #ls -l

-rw-r--r-- + root  root ---- ----  f1

2) non-trival entry:-

********************

if the perm of file/dir contains "." symbol after permissions then the file/dir is not having ACL permissions

ex: #ls -l 

-rw-r--r-- . root  root  ----- ------ f1

to get acl perm of file/dir:-

****************************

#getfacl  <file/dir name> 

ex: #getfacl f1

file: f1

owner: root

group: root

user: rw-

group: r--

others: r--

setting  acl perm for file/dir:-

******************************

#setfacl -m   u:<username>:<permission>,g:<groupname>:<permission>    <file/dir name>

ex: #setfacl -m u:zafar:rw-,g:kxip:---  f1

-m --> add/modify acl perm on  perticular user or group

#setfacl -Rm  u:<username>:<permission>,g:<groupname>:<permission>    <dir name>  

ex: #setfacl -Rm u:zafar:---,u:red:---,g:kxip:rwx    d1

-Rm  --> to recursively add/modify the acl permission on dir

#setfacl -x  u:<username>,g:<groupname>    <file/dir name> 

ex: #setfacl -x u:zafar,g:kxip    f1

-x --> to remove acl permission for perticular user or group

#setfacl -b <file/dir name>  

ex: #setfacl -b f1  

-b --> to setback to default  ACL permission

mask -> the max permission that can be given to perticular user or group on perticular file or dir