Day2 &3 -#90DaysofDevops Introduction to DevOps
Tags: 90daysofdevops, devops, linux, opensource
Published: 2023-04-11 16:21:53

**Q: What is Linux?**

Linux is a family of free and open-source operating systems based on the Linux kernel. Operating systems based on Linux are known as Linux distributions, or distros. Examples include Debian, Ubuntu, Fedora, CentOS, Gentoo, Arch Linux, and many others.

The Linux operating system's architecture mainly contains the following components: the kernel, system library, hardware layer, system, and shell utility.



**Basic Linux Commands:**

`ls` - > List all directories/files

`ls -a` -> List all files along with hidden files

`ls -R` -> shows all files in a subdirectory

`cd` ->for changing the directory

`cat` -> It can be used to create a file, display the content of the file, copy the content of one file to another file, and more.

`touch `-> for creating empty files

`mkdir` -> to make a new directory

`cp` -> To copy files

`mv` -> to move files around

`rm` -> to remove files


**Directory commands**

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

`cd path_to_directory `--> Change the directory to the provided path

`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

## Tasks:

**To view what is written in file**

```
Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ echo "Learning devops.." >task.txt

Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ cat task.txt
Learning devops..
```

**To change the access permissions of files.**

```
Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ ls -l  task.txt
-rw-r--r-- 1 Arunima 197121 18 Apr 10 16:21 task.txt

Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ chmod 765 task.txt

Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ ls -l  task.txt
-rw-r--r-- 1 Arunima 197121 18 Apr 10 16:21 task.txt
```

**3)To check which commands you have run till now.**

```
Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ history
.. 
167  mkdir day3
  168  cd day3
  169  echo "Learning devops.." >task.txt
  170  cat task.txt
  171  ls -l  task.txt
  172*
  173  ls -l  task.txt
  174  chmod 765 task.txt
  175  ls -l  task.txt
  176  chmod 777 task.txt
  177  history
```

**4)To remove a directory/ Folder.**

```
Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ mkdir random

Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ ls
random/  task.txt

Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$  rm -rf random/

Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ ls
task.txt
```

**5)To create a fruits.txt file and to view the content.**

Here we used vim to create a file . Then we enter shift+i and entered contents then ecp and :wq to return

to view content we used cat command

```
Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ vim fruits.txt


Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ cat fruits.txt
apple
mango
cherry
banana

```

**
6)Add content in devops.txt (One in each line) - Apple, Mango, Banana, Cherry, Kiwi, Orange, Guava.**

```
Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ vim devops.txt
```

**7)To Show only top three fruits from the file.**

```
Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ head -3 devops.txt
Apple,
Mango,
Banana,
```

**8)To Show only bottom three fruits from the file.**


```
$  Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ tail -n 3 devops.txt
```

**9)Create a file colour .txt add content and view it**

```
Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ vim colour.txt

Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ cat colour.txt
Red
pink
white
black
blue
orange
purple
grey
```

**10)To find the difference between fruits.txt and Colors.txt file.**


```
Arunima@DESKTOP-JETUU7R MINGW64 /e/devops-handson/90days/day3 (master)
$ diff colour.txt fruits.txt
1,8c1,4
< Red
< pink
< white
< black
< blue
< orange
< purple
< grey
---
> apple
> mango
> cherry
> banana
```

Do share your thoughts. I'll work on it and try to get better. Thank you.
~ Arunima