Challenge_01

*********************The Linux Terminal*************************
1. Run the following command both as a non-privileged user and as root: tail /etc/shadow
Sol.
Non-privileged user-: tail /etc/shadow
-> tail: cannot open '/etc/shadow' for reading: Permission denied
Privileged user-: sudo tail /etc/shadow
-> [sudo] password for prateek: 
 hplip:*:18474:0:99999:7:::
 whoopsie:*:18474:0:99999:7:::
 colord:*:18474:0:99999:7:::
 geoclue:*:18474:0:99999:7:::
 pulse:*:18474:0:99999:7:::
 gnome-initial-setup:*:18474:0:99999:7:::
 gdm:*:18474:0:99999:7:::
 prateek:$6$u4f3GbYvPkYaPRQt$KdN/  SmmJ91NmcoDlb9LoThTDsJyT7eQxdkurqPzpVeuDasu4KSa04aAD.dYYXrmNLIush1XoQI  KhxyCa2EJ5a0:18521:0:99999:7:::
 systemd-coredump:!!:18521::::::
 vboxadd:!:18521::::::


2.  Become root temporarily in a terminal.
    Run the following command as root: apt update && apt install nmap
    Logout root from the terminal using a keyboard shortcut
Sol.
su 
-> Password: 
apt update && apt install nmap
-> nmap will install
ctrl+d
-> terminal closed


3. Change (set) the root password
   Become root in a terminal by running the su command
   Run as root the following command: lshw
Sol.
sudo passwd root
-> [sudo] password for prateek: 
     New password: 
     Retype new password: 
     passwd: password updated successfully
su
-> Password: 
lshw
-> prateek-virtualbox          
   description: Computer
   product: VirtualBox.......


4.  Display the user’s history
Remove line no. 4 from the history
Run a command without being recorded in the history. Check that it wasn’t saved in the shell history.
Remove the entire history.
Sol. 
history
-> shows the history list
history -d 4
-> line no. 4 was removed
 pwd
-> /home/prateek
history
-> " pwd" wasn't saved in the history because the environment variable, HISTCONTROL= ignorespace