bash shell scripting

Question 1

what is a kernel in Linux?

Answer 1

It manages the computer’s hardware, like the CPU and memory, and allows software programs to use these resources. Think of it as the bridge between the computer’s hardware and the applications you run.

Question 2

what is a shell in Linux?

Answer 2

In Linux, a shell is a program that lets you interact with the operating system using text commands.

Question 3

name some shells you know

Answer 3

• Bash (Bourne Again Shell)
• Zsh (Z Shell):
• Ksh (Korn Shell)
• Fish (Friendly Interactive Shell) etc…….

Question 4

how can you see all the shells you have installed in your Linux machine?

Answer 4

cat /etc/shells

Question 5

what is the command to find the shell you are currently using ?

Answer 5

echo $0

Question 6

what is a shell script ?

Answer 6

A shell script is a file containing a series of commands that are executed by a shell.

Question 7

what is in the first line of a shell script?

Answer 7

the shell eg #!/bin/bash

Question 8

what kind of permissions should a shell script have ?

Answer 8

executable permissions eg (-rwx r-x r-x)

Question 9

how can you call a shell script ?

Answer 9

• use the absolute path (eg /home/file1/install.sh)
  -use the relative path ./install.sh

Question 10

run a script that will output “hello world”

Answer 10

!/bin/bash

-touch a file

echo “hello world”

• give it execute permission (chmod +x filename)
• run the script (./filename)

Question 11

run a script from an absolute path

Question 12

what is a variable in shell scripting ?

Answer 12

In shell scripting, a variable is a placeholder that stores a value, which can be used and manipulated throughout the script.

Question 13

create a script, define some variables and call the variables.

Answer 13

1. touch a file
   #!/bin/bash

a=apple
b=pear
c=oranges

echo “my favorite fruit is an $a”
echo “my sister loves $b”
echo “I use $c to make juice”

• give it execute permission (chmod +x filename)
• run the script (./filename).