Shell Scripting Courses

Introduction Shell

If you are using a main operating system, interact indirectly with the shell.

If you are using Ubuntu, Linux Mint, or another Linux distribution, you interact with the shell each time you use the terminal.

In this article, I will talk about Linux shell shells and scripts.

Before understanding the shell script, we need to familiarize ourselves with the following terminology:

Kernel:

The kernel is a computer program that makes up the heart of a computer’s operating system and has complete control over everything in the system.

It manages the following features of the Linux system:

It is often wrong that Linus Torvalds developed a Linux operating system, but in fact, he is solely responsible for the development of the Linux kernel.

What is Shell :

A shell is a special user program that provides the user with an interface to use the services of the 

operating system.

The shell is started when the user logs in, or the terminal is started.

Shell Scripting:

Shells are generally interactive, which means that they accept commands and execute them.

However, for a while, we would like to execute a series of commands regularly, so we have to enter all commands in the terminal each time.

Since the shell can also use commands as input to the file, we can write that commands to the file and execute them in the shell to avoid this repetitive work.

The shell scripts are similar to the batch file in MS-DOS.

Each shell script is saved with a .sh file extension, for example, myscript.sh

A shell script, like any other programming language, has syntax.

If you already have experience with programming languages ​​like Python, C / C, etc., it is very easy to get started.

Create a shortcut in Linux:

This can be done using existing links on Linux.

Hardlink: hard links are linked to the file inode and must be on the same file system as the file.

Deleting the original file does not affect the physical link.

Software link: Software links are linked to the file name and can also be located on another file system.

Deleting the original file makes the software link inactive.

Superblock in shell scripts:

A superblock is essentially the program that contains the record of certain file systems.

Features such as block size, empty and filled blocks, and their respective numbers, size and position of node tables, information on the use and allocation of plate blocks and the

size of block groups is available in a superblock.

The graphical user interface is used to control a computer and its applications.

C shell a more preferred option than the Bourne shell:

It is a more preferred option in the following cases:

All commands can be easily modified with the C shell, unlike the Bourne shell.

Long commands can be used repeatedly in the C shell, while Bourne does not allow this in all cases.

The command history is accessible via the C shell, but not via Bourne.

Why should go for Unix Shell Scripting

1. The robust extent of shell scripts

The main reason for the popularity of Unix Shell Scripting is its robust scope.

It is a powerful programming method that helps you learn the command-line better, save time, and perform tedious file management tasks.

Shell scripts are at the heart of the operating system!

With the growing need for rapid processing of large amounts of data generated by applications, Unix is ​​more than ever used to significantly reduce the processing time of jobs.

Therefore, it is not surprising that a survey conducted by ZDNet in 2015 shows that Unix has grown faster than any other server operating system in recent years.

1. Career development

Although the demand for Unix shell script talent continues to grow, there is still a shortage of experienced professionals in the market.

Developers and system administrators familiar with Unix Shell scripts have unlimited career opportunities.

A quick search on LinkedIn shows that there are 214,380 LinkedIn members who have this capability, and there is no sign of slowing demand.

Some functions that you can assume with Unix knowledge are:

IBM, eBay, CISCO, Aol, Intel, and Salesforce are some of the companies looking for IT staff with Unix Shell Scripting training.

Unix knowledge can also help IT professionals get involved in high-paying areas such as ETL development/testing, Big Data, and Hadoop development/testing, Java development/testing, Java

development/testing, support for SQL Unix production, and many other areas to diversify.

However, choose an additional option for shell scripts, for example, B.

Unix system administration to get the best job offers.