• Introduction to Linux shell
• Common Linux shells
• What is shell scripting
Introduction to Linux Shell
It is not part of the kernel. Through this, the user uses the kernel and performs many different tasks.
The shell is accessed by a terminal. The terminal is used to open and use the shell.
Whenever the user types a command in the shell, the shell passes that command to the kernel, after which the kernel executes that command.
The shell acts as a bridge between the user and the Linux kernel. Shell is a non-GUI way to interact with the operating system. Shell is available in all operating systems.
A computer understands only the binary language of 0 and 1. Shell takes a command from the user in simple English form and converts it to binary and passes it to the kernel if the command is appropriate.
To see the available shells in Linux, you can execute the $ cat / etc / shells command in the terminal. To see the current shell, you can execute the command $ echo $ SHELL.
You can use the echo “$ shell” command to see the available shells on Mac Os.
In the Microsoft Disk Operating System (MS-DOS), the shell is named COMMAND.COM. Which can be accessed via command prompt.
A shell program can be given commands by keyboard or mouse. When commands in the shell are given by the keyboard, it is called a command-line interface.
Common Linux Shells
In the Linux operating system, you have many shells available. Some popular Linux shells are being described below.
The first shell of Unix was the Bourne shell made by Stephen R. Bourne in Bell Labs in the 70s.
BASH (Bourne-Again Shell)
Bash is a Unix shell. It was created to replace the Bourne shell. If the reason is that it is named bourne-again shell. It was created by Brian Fox.
Apart from Unix, it has also been used as the default login shell on Linux and Mac OS. A version of this shell is also available for Windows 10.
The C shell is also a Unix shell. It was created by Bill Joy in the 1970s. This is a command process shell. In this, commands can also be processed by passing a file. Which is called script.
Korn shell is a Unix shell made on the basis of the Unix shell. David Korn developed it in bell labs. Many features have also been included from the C shell.
Tee See Shell is the modern Unix shell. It is based on the C shell and is capable of working with it. You can understand it as a C shell with some extra features (command line editing etc.).
What is Shell Scripting
Shell scripting means executing commands to a list stored in a file. These commands are executed in a fixed order to perform a certain task and their order can be changed according to the task.
Shell is a language apart from being a program. It is like creating a program in C language and executing use. C programming is also a sophisticated form of shell scripting.
Comments can also be defined in shell scripting and output can be seen.