 So, I will be explaining the advanced UNIX command, you need to open a terminal, go to application accessories then terminal. So, I have opened the terminal here, I will explain few of the UNIX commands now. First is DU, it is used to see the directory size. So, you are in your after going to opening the terminal, you will be in your home directory, type PWD to see the current directory, your current directory will be different than mine. So, if you want to check the size of your home directory, you can enter DU minus SH command, S is for summary H is for human readable format. So, after entering this command, you will see the size of your home directory, here I am seeing the size of my home directory as 60 megabytes. I will move to the next command that is PS, PS is used for seeing the processes that are running on your system currently. So, if you want to see all the processes that are running on your system, you can enter PS minus EF, it will print the list of all the processes that are running on your system. So, go up and process statistics, process statistics. So, first field is UID that is the which is who is the user that is running the process. Second thing is PID of the process. So, as you can see as you know in it is the process with PID 1 always and that is started by root. So, you can see root has started this process, PID of the process is 1, next field is parent PID that is parent process number and then there are some more fields which you can see using man PS command. Now, you want to see the processes which are run by the particular user. So, with who am I command I am seeing the my user name. So, entry is IITB. So, I am I have logged in using IITB. So, I want to see all the processes which are started by me. So, I will write command as PS minus U space IITB. So, it will list all the processes that are started by me, this is the list. So, you can see this is Firefox then for opening PID PPT I have used open office and then this is the bash shell and this is the command that I have just run PS this command. Next command is add user. So, you want to add some user on your system who can who will be also able to access the system. So, for that you need to run add user command. So, instead of running all this command with all these options you can just type add user space user name. So, I will type add user space test user. Test user is my user name that is to be added. So, it is giving only root may add this option. So, I will write I will run this command using sudo sudo space add user space test user. This is using me since I have run the sudo command it is using asking the password for my current user. So, now as you can see the messages it is displaying adding user test user. Since we have not given the group to which this user has to be added it is creating a group as test user only and it is adding this user to test user group. It will create the default home directory of the user as slash home slash test user and these are some configuration files required which is which it is copying. So, you can give the password for this new user I am giving the password as 1 2 3 4 it will again ask for the password 1 2 3 4 it will ask the other details that you can skip you can just press enter at the end it will ask is the information correct you have to press Y and enter. Now, this test user is added on your system. So, how can you check if it is really added or not for that for that I have run the command as su space test user. So, basically I want to login as test user. So, I have run this command it has asked me for the password of test user I had supplied the password as 1 2 3 4 and then you as you can see I am currently logged in with test user previously it was IITV at my laptop name that is IITV dash laptop. Now the user is test user at IITV dash laptop. So, this user is indeed created you can go to the home directory of the user with CD enter. So, it will go to the home directory you can check the home directory with PWD command. So, this home directory you can see as slash home slash test user which was created by add user command slash home slash test user. Next thing is deleting the user. So, I will delete the user that I had just created the command is del user del user space user username which is to be deleted. So, I will delete the test user I need to first log out of this user I will log out using control D. Now it has previously I was logged in as test user now it has changed to IITV. Now I will use the del user command to delete this user control D. So, you can delete the user with this again it is asking for root permissions. So, I will run it as sudo space del user space test user it is giving the output as removing the user test user. And since test user was only user in the group test user it is removing the group test user also. So, this is addition and deletion of the user. Next thing is how do you check the disk usage of your file system. So, command is df for human readable format we are using df minus h. So, if you enter this command it will list the partitions slash dev slash sda5 then other partitions. The size of those partitions the usage available size usage and percentage and which is the directory on which these devices are mounted. So, slash dev slash sda2 is mounted at slash boot what it means is the data which is containing in this device will be accessible if you go to slash boot. The next command is f disk. So, f disk for you can see and create the partitions with this command I will just display whatever the partitions are there on my system currently. So, f disk minus l gives me this output. So, these are the devices on your file system. What it means is on your window system you have c drive read out the e drive like that here we have the devices as sda1, 2, 3, 5 and these devices are accessible on partitions on which we have mounted these things. So, sda2 will be accessible through slash boot sda7 will be accessible through slash home. This command if config command you have already encountered I will still show you sudo if config enter this will display your network configuration. So, if 0 is the network interface that you are using the IP address of your system is IP address of this network interface is 10.910.32.113 and then this MAC address of the system is this and similarly you can see other details. If you do man if config you will know what are all the entries this completes our advanced Unix command presentation. Thank you.