**admin@ip-10-1-13-234:~$ sudo groupadd read
admin@ip-10-1-13-234:~$ ls
README.txt  agent  shared
admin@ip-10-1-13-234:~$ cd shared/
admin@ip-10-1-13-234:~/shared$ ls
ALL  project_abe  project_betty  project_carlos  project_debora
admin@ip-10-1-13-234:~/shared$ sudo chgrp read ./project_abe ./project_betty ./project_carlos ./project_debora 
admin@ip-10-1-13-234:~/shared$ sudo chmod g+r ./project_abe 
admin@ip-10-1-13-234:~/shared$ sudo chmod g+r ./project_betty 
admin@ip-10-1-13-234:~/shared$ sudo chmod g+r ./project_carlos 
admin@ip-10-1-13-234:~/shared$ sudo chmod g+r ./project_debora 
admin@ip-10-1-13-234:~/shared$ sudo usermod -a -G read abe
admin@ip-10-1-13-234:~/shared$ sudo usermod -a -G read betty 
admin@ip-10-1-13-234:~/shared$ sudo usermod -a -G read carlos 
admin@ip-10-1-13-234:~/shared$ sudo usermod -a -G read debora 
admin@ip-10-1-13-234:~/shared$ sudo su abe
abe@ip-10-1-13-234:/home/admin/shared$ cat project_betty 
This is betty's project file
abe@ip-10-1-13-234:/home/admin/shared$ exit
exit
admin@ip-10-1-13-234:~/shared$ sudo chattr +a ./project_abe 
admin@ip-10-1-13-234:~/shared$ ls -l
total 20
-rw-r--r-- 1 root   admin 38 Feb  2  2025 ALL
-rw-r----- 1 abe    read  27 Feb  2  2025 project_abe
-rw-r----- 1 betty  read  29 Feb  2  2025 project_betty
-rw-r----- 1 carlos read  30 Feb  2  2025 project_carlos
-rw-r----- 1 debora read  30 Feb  2  2025 project_debora
admin@ip-10-1-13-234:~/shared$ sudo chattr +a ./project_betty 
admin@ip-10-1-13-234:~/shared$ sudo su abe
abe@ip-10-1-13-234:/home/admin/shared$ vi project_abe 
abe@ip-10-1-13-234:/home/admin/shared$ sudo chattr -a ./project_abe 

We trust you have received the usual lecture from the local System
Administrator. It usually boils down to these three things:

    #1) Respect the privacy of others.
    #2) Think before you type.
    #3) With great power comes great responsibility.

[sudo] password for abe: 


Sorry, try again.
[sudo] password for abe: 
^C
sudo: 2 incorrect password attempts
abe@ip-10-1-13-234:/home/admin/shared$ 
abe@ip-10-1-13-234:/home/admin/shared$ 
abe@ip-10-1-13-234:/home/admin/shared$ 
abe@ip-10-1-13-234:/home/admin/shared$ exit
exit
admin@ip-10-1-13-234:~/shared$ sudo chattr -a ./project_betty 
admin@ip-10-1-13-234:~/shared$ sudo chattr -a ./project_abe 
admin@ip-10-1-13-234:~/shared$ sudo su ab
su: user ab does not exist or the user entry does not contain all the required fields
admin@ip-10-1-13-234:~/shared$ sudo su abe
abe@ip-10-1-13-234:/home/admin/shared$ vi project_abe 
abe@ip-10-1-13-234:/home/admin/shared$ cat project_abe 
This is abe's project file

fdsf
abe@ip-10-1-13-234:/home/admin/shared$ ^C
abe@ip-10-1-13-234:/home/admin/shared$ sudo chattr +a project_abe

We trust you have received the usual lecture from the local System
Administrator. It usually boils down to these three things:

    #1) Respect the privacy of others.
    #2) Think before you type.
    #3) With great power comes great responsibility.

[sudo] password for abe: 
sudo: a password is required
abe@ip-10-1-13-234:/home/admin/shared$ exit
exit
admin@ip-10-1-13-234:~/shared$ sudo chattr +a project_abe 
admin@ip-10-1-13-234:~/shared$ sudo su abe
abe@ip-10-1-13-234:/home/admin/shared$ echo "hi" >> project_abe 
abe@ip-10-1-13-234:/home/admin/shared$ cat project_abe 
This is abe's project file

fdsf
hi
abe@ip-10-1-13-234:/home/admin/shared$ exit
exit
admin@ip-10-1-13-234:~/shared$ sudo chattr +a project_betty 
admin@ip-10-1-13-234:~/shared$ sudo su betty
betty@ip-10-1-13-234:/home/admin/shared$ echo "sezz" >> project_betty 
betty@ip-10-1-13-234:/home/admin/shared$ cat project_betty 
This is betty's project file
test
sezz
betty@ip-10-1-13-234:/home/admin/shared$ exit
exit
admin@ip-10-1-13-234:~/shared$ sudo chattr +a project_carlos 
admin@ip-10-1-13-234:~/shared$ sudo chattr +a project_debora 
admin@ip-10-1-13-234:~/shared$ ls -l
total 20
-rw-r--r-- 1 root   admin 38 Feb  2  2025 ALL
-rw-r----- 1 abe    read  36 Sep  1 18:03 project_abe
-rw-r----- 1 betty  read  39 Sep  1 18:04 project_betty
-rw-r----- 1 carlos read  35 Sep  1 17:57 project_carlos
-rw-r----- 1 debora read  35 Sep  1 17:57 project_debora
admin@ip-10-1-13-234:~/shared$ sudo su abe
abe@ip-10-1-13-234:/home/admin/shared$ cat project_betty 
This is betty's project file
test**
sezz