What is a shell in a computer

what is a shell in a computer.

What is a shell in a computer


What is Shell


Many people have heard the word shell in computers but don't know what it really is. In this article, the admin will discuss what a shell is in the computer world.


Also Read: What is PowerShell? Here's a Complete Explanation

TABLE OF CONTENTS

1. What is Shell

2. Shell Type

3. 1. Bourne Shell

4. 2. C Shell

5. What is Shell Scripting

6. Conclusion


What is Shell


A shell is a macro processor or command language interpreter that translates commands, written by the user at the terminal, into executed system actions, which can also be automatically executed in a program called Shell Scripting. The shell existed before the mouse was invented, as it was the only way to interact with computers in the past.


The shell is also not an operating system. It is a way to interact with the operating system and execute commands. The terminal window on our computer contains a shell that allows us to process information, store or retrieve data and much more by interacting with the computer through entering commands. As an example:

  * Retrieve a list of files or directories

  * Look up today's date and time

  * Get current directory location

  * Create, copy or delete files

  * Sorting files


The term shell comes from the use of consoles under UNIX operating systems in the 70s, where they connected to a central computer and started working there. With the rise of GNU/Linux distributions, users have several shell types available and these are: sh, csh, ksh, etc.

Also Read: Here Are The Differences Between Unix And Linux


Shell Type


As the admin mentioned earlier actually there are various types of shells, but on Unix there are only 2 main shell types, namely Bourne Shell and C Shell.


1. Bourne Shell


The Bourne Shell (sh), written by Steve Bourne at AT&T Bell Labs, is the original UNIX shell. It is the preferred shell for shell programming because of its compactness and speed. The disadvantage of the Bourne shell is that it lacks features for interactive use, such as the ability to remember previous commands (history).


The Bourne Shell lacks built-in arithmetic and logical expression handling. But Bourne Shell is also Solaris OS's default shell. This is the standard shell for Solaris system administration scripts.


2. C Shell


The C shell (csh) is a UNIX enhancement written by Bill Joy at the University of California at Berkeley. Features included for interactive use, such as aliases and command history. Includes easy-to-use programming features, such as built-in arithmetic and expression syntax. C-like.


What is Shell Scripting


In the simplest terms, a shell scripting is a file that contains a series of commands for the shell to execute. The shell reads this file and executes commands as if they had been entered directly on the command line.


It can combine long and repetitive command sequences into a single and simple script, which can be saved and executed at any time. This reduces the effort required by the end user.


Because with thousands of commands available to command line users, how can we remember them all. We need the power of computers to do the job. To do so, we can use the power of this script shell to automate these things.


Actually the shell is rather unique, because it is a powerful command line interface for the system and scripting interpreter. Most of the things that can be done on the command line can be done in a script, and most of the things that can be done in a script can be done on the command line.


Conclusion

So what are shells? Simply put, a shell is a software interface used by the Command Line Interface (CLI) that allows the user to interact with the computer. Usually this deals with files and programs, but some of the more advanced shells allow you to perform operations like complex programs. Some examples of shells are sh, csh, ksh, and many more.

Hopefully, this article about What is a shell in a computer, gives you a little insight. Also, read an article about What is a swap partition in Linux and what does it do? that you may need to know. Thank you.

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