====== Posfix ACLs ======
===== What is ACL? =====
Due to the limitations of permission/ownership setup with the files/folder in Linux (for example we cannot setup different permission for different users to access the same file). To overcome this problem ACL(Access Control Lists) are introduced. We can use the setfacl & getfacl command to setup the acl for folder and files.
===== Setting up ACL’s using setfacl =====
In the below example, i have created two separate users called user1 and user2 and i am going to setup full access and partial access  to the /root directory for this two users (which is the home directory for root). The first user user1 will have full and the second user2 have only the read and execute permissions.
<code>setfacl -m u:user1:rwx /root
setfacl -m u:user2:rx /root
</code>

===== Copy ACLs =====
<file>
getfacl file1 | setfacl --set-file=- file2
</file>

===== Copy ACLs all items in a directory =====
<file bash acl.sh>
#!/bin/sh

LIST="`cd /vol1/public/Data && ls | sed \"s/ /_/g\"`"

for i in $LIST
do
        ITEM="`echo $i |  sed \"s/_/ /g\"`"
        getfacl /vol1/public/Data/"$ITEM" | setfacl --set-file=- /vol2/public/Data/"$ITEM"
done
</file>