Day2-Getting started with Linux

Linux History

Hello readers!! Before we get into the basics of Linux, a little history as to how this most powerful OS came into existence.

As we all know, in the past computers were as large as homes or parks and each of them was operating with different operating systems making it difficult to be understood and afforded by normal people.

In 1969, a team of engineers at Bell Labs created software that can work on all computers and used C language instead of assembly and called it UNIX. This was recyclable and open-source too, however, it remained a bit costly for normal people to afford. Many other Unix-like operating systems came into existence but none of them was able to gain popularity.

In 1991, Linus Torvalds a student at the University of Helsinki, Finland, thought to have a freely available academic version of Unix and started writing his code. Later this project became the Linux kernel. He started it just for fun but ended up with such a large project. Fast forward to today, Linux is one of the most powerful OS and is being used in smartphones, desktops, web servers, tablets, laptops, washing machines, DVD players, routers, modems, cars etc.

Linux Architecture

Linux System Architecture consists of following layers :

1. Hardware layer - This is the bottom-most layer of the Linux architecture and represents the physical hardware components of the computer, such as the processor, memory, and storage.

2. Kernel - It is the heart of the Linux operating system where the core code is stored. It can interact directly with the hardware. The kernel is in charge of creating an appropriate abstraction for concealing trivial hardware or application strategies.

3. Shell - Shell is an interface between the kernel and the user, hiding the complexity of the kernel's functions from users. It is environment in which we can run our commands, programs, software and shell script.

4. Application program/Utilities - This is the topmost layer of the Linux architecture and consists of the various applications that run on the operating system. These can be anything from productivity software and games to web browsers and media players.

Basic Linux Commands

• ls -l--> list the files and directories in long list format with extra information

• ls -a --> list all including hidden files and directory

• pwd --> print work directory. Gives the present working directory.

• cd path_to_directory --> change directory to the provided path

• cd ~ or just cd --> change directory to the home directory

• cd - --> Go to the last working directory.

• cd .. --> change directory to one step back.

• cd ../.. --> Change directory to 2 levels back.

• mkdir directoryName --> to make a directory in a specific location

Examples

1. Linux command to check present working directory

   

2. List all the files or directories including hidden files.

   

3. Create a nested directory A/B/C/D/E

   

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