Chapter 1. Getting Started and Working with Shell Scripting

Whoever works with Linux will come across shell as the first program to work with. The Graphical user interface (GUI) usage has become very popular due to the ease of use. Those who want to take advantage of the power of Linux will use the shell program by default.

Shell is a program which provides the user direct interaction with the operating system. Let's understand the stages in the evolution of the Linux operating system. Linux was developed as a free and open source substitute for UNIX OS. The chronology can be as follows:

• The UNIX operating system was developed by Ken Thomson and Dennis Ritchie in 1969. It was released in 1970. They rewrote the UNIX using C language in 1972.
• In 1991, Linus Torvalds developed the Linux kernel for the free operating system.

In this chapter, we will cover the following topics:

• Comparison of shells
• Working in shell
• Learning basic Linux commands
• Our first script—Hello World
• Compiler and interpreter—difference in process
• When not to use scripts
• Various directories
• Working more effectively with shell—basic commands
• Working with permissions