There was a big gap between Day 1 & 2 on the writings. Maybe, I should change the title to weekly notes.

So, instead of writing command notes, I now prefer to write in a narrative story-telling way about Linux.

What is Kernel?

What you sow is what you reap

But you may ask what it has to do with Linux! You would have heard the words “root” , “kernel” and “shell”. Now getting on to the topic, Linux is referred many time as kernel. Kernel in plain English is the seed. Just think of it like paddy, seed of a rice covered by a shell of husk. And when the kernel is sowed, a single seed will bear into many. In such a way, here in Linux, Kernel being the central process of an operating system manages the operation connecting with the hardware.

You got SUed!

When we combine the command su with sudo, it switches user. As we know sudo command provides a higher privileged access to whoever added to the sudoers group, so when you type sudo su followed by the username you want to login to that user account by providing that user’s password. Now, if you try “sudo su -” and the user name, surprisingly you will notice the ~ tilde is still present in the terminal notifying you that you still present in your home directory but logged in to the other user account.

I will stop here to find yourself on the answer. If you get the answer before my second write-up, please feel free to discuss with me.

Bye for now!!!

On today’s class we learnt about few beginner commands on Linux. The commands that are used to navigate around directory and creating, modifying the files and learnt about the user details present on the terminal.

Commands practiced are:

1. ls – This command is used to list files in the present directory/folder. We can use the arguments -lh to list the files in long, detailed and in human readable format
2. cat – This is a concatenate command which can be used to create, view and concatenate (join two files) files
3. echo – This command prints the text served after its name. It echos the text back
4. sudo – This command is used to elevate your user privileges(special access). For example: if you would like to print the sudoer file which is in directory /etc/sudoers, you will get a message stating “permission denied” and you need to use command “sudo /etc/sudoers” to print this file. But remember, you should still be added to the sudoer group by the admin to perform the sudo command in that machine.
5. Tab Tab: The other useful key in terminal is, if you press the tab button after typing few characters of the filename or the directory name, it will auto-fill.

Now, Let’s analyze the info’s present inside the terminal.

What is a terminal? A terminal is an emulator which presents a screen interface to the user with which we can instruct/command the kernel to get the job done.

The above screen will get displayed when you open the terminal (In Ubuntu press Ctrl + t for short-cut key)

You will be welcomed with the same as above screen once you open up the terminal and it will contain username@hostname followed by $ dollar symbol. Your username is kind of your account name that you used while setting up the OS and the host-name is your computer/machine name. This convention becomes handy to identify the remote machine when we login remotely from our host machine.

The $ dollor symbol indicates that the terminal is ready for prompt/command to be supplied from user.

There are other lots of command covered in today’s class but that’s it for the day i can write about.

The Journey will continue…. Stay focused!