Permissions

• Create an empty file in your home directory named Test!

feri@aries:~$ touch Test

• Set permissions for this file: the owner must be able to read, write and execute, members of the group should read and execute, others do not have any permissions!

feri@aries:~$ chmod 750 Test

• Change the ownership of this file! The new owner should be the system administrator! (Why doesn't it work?)

feri@aries:~$ chown root Test

• Let the group of that file be the staff group! (Why doesn't it work?)

feri@aries:~$ chgrp staff Test

• Change its privileges to: rw-r--r--! What does it exactly mean?

feri@aries:~$ chmod 644 Test

• When other users run this file, they should have your rights. How can you reach that?

feri@aries:~$ chmod 4755 Test
OR
feri@aries:~$ chmod u+s Test

• This file sould run with the group rights!

feri@aries:~$ chmod 2755 Test

• Create a directory named TestDir! How can you reach that all users be able create files there but be able to to delete only their own files in it!

feri@aries:~$ mkdir testDir
feri@aries:~$ chmod 1777 testDir

• Create a directory named Common! It should be really common, all users must be able to create and delete any files in it. How can you reach it?

feri@aries:~$ mkdir Kozos
feri@aries:~$ chmod 777 Kozos

• Ask your own identifier and your group identifier!

feri@aries:~$ id

• Change to an anoter user temporary! (Use your classmate's name and password!)

feri@aries:~$ su - neighbor

• Review the contens of the /etc/passwd and the /etc/group files! What are the meanings of fields in lines?

feri@aries:~$ cat /etc/passwd
feri@aries:~$ cat /etc/group