Shell scripting for Devops

A shell script is a file in which you have written shell commands in sequences.

Let’s talk about file types:

If we have a Python file, then the file type is (.py).

Similarly,

Python - (.py)

Java - (.java)

C++ - (.cpp)

C - (.c)

Shell - (.sh)

username.sh for making a folder, here, ‘sh’ is the file type.

In shell commands, firstly we use Shebang (#!/bin/bash).

\It tells the computer which programme (shell) should be used to run the rest of the script.

And after that, executing permission( ls-l).

then give a permission according to your work

like if you want the file which name is vikash.sh, you have to give read, write, execute permission then

chmod764 vikash.sh

after that for executing file then use (./vikash.sh)

lets create some examples for you

in file vim vikash.sh

hero = “rancho”

here “hero” is variable

here = is operator

and “rancho” is value

So, if we want to print, we have to use a variable.

Hero = “Raja”

Villain = “Shivam”

Then,

echo “Movie hero is $Hero”

echo “Villain is $Villain”

After saving it using [esc :wq]

Give permission to this file using

chmod 764

After that,

Execute the file by using (./vikash.sh)

PREDIFIEND USER EXAPLE

echo “Current logged-in user: $USER”

If we want to take input from the user, then

read -p “What is Rancho’s full name?” fullname

echo “Full name of Rancho is $fullname”

CREATE USER USING SHELL

read -p "enter the user name:" username

read -p "enter tha pssword:" "password"

useradd -m -p "$password" "$username"

for making the user name with virus then ⬇️

it will create user