Introduction to Ubuntu 20.04 Shell-Bash

What is Shell?

Shell is a command-line interpreter that allows programmers to interact with the operating system using commands written in a programming language known as Shell Script. The Shell Script is primarily used for automating tasks, performing administrative tasks, and creating custom commands.

Ubuntu 20.04

Ubuntu 20.04 is the latest Long Term Support (LTS) release of Ubuntu, which means that it will be supported with security updates and bug fixes for the next five years. Ubuntu 20.04 has many improvements, including:

• Improved desktop environment
• Faster boot times
• Improved packaging system
• Improved security features
• Updates to core software packages

Shell-Bash

Bash is the default Shell language used in Ubuntu, as well as most Linux operating systems. Bash is a powerful and versatile programming language that allows you to create and automate complex workflows, manipulate files and directories, and manage processes.

Get started with Bash

To get started with Bash, you can launch the Terminal application on Ubuntu 20.04, which provides a command-line interface to interact with the operating system. To create a new Shell script, use any text editor to create a file with a .sh extension.

Here is an example of a simple Bash script that prints "Hello World!" to the console:

#!/bin/bash
echo "Hello World!"

The #!/bin/bash line at the beginning of the script tells the operating system to interpret and execute the script using the Bash shell.

Basic Bash Commands

• ls: List the contents of the current working directory
• cd: Change current working directory
• mkdir: Create a new directory
• touch: Create a new file
• rm: Remove a file or directory
• cp: Copy a file or directory
• mv: Move or rename a file or directory

Bash Programming Structures

Bash programming structures include conditional statements, loops, and functions.

Conditional Statements

Conditional statements are used to execute code based on whether a condition is true or false. The most common conditional statements in Bash are if, else, and elif.

if [ $x -eq 10 ]
then
  echo "x is equal to 10"
else
  echo "x is not equal to 10"
fi

Loops

Loops are used to repeat a section of code until a condition is met. The most common loops in Bash are for, while, and until.

for i in {1..5}
do
  echo $i
done

Functions

Functions are used to group a set of commands into a single unit, making them easier to reuse and maintain.

say_hello () {
  echo "Hello, $1!"
}

say_hello "John"

Conclusion

In conclusion, Ubuntu 20.04 with Bash Shell is a powerful combination for programmers looking to execute complex tasks, automate workflows, and manage processes. With the vast array of commands, structures, and functions available, Bash provides endless possibilities for programmers looking to optimize their workflow and improve productivity.