Before we actually go in-depth of shell scripting let's first see what is shell scripting and why is it needed for us.
Shell scripting is a form of programming which can save you a lot of time.
Earlier, when GUIs were not affordable, computer users access the system using terminal program, which is a keyboard interface.All commands passed to the system using keyboard.For e.g., to open a text file in windows GUI interface we look for the file and right click on the icon and select open-with and click on any of the available text editor for instance notepad.The same task can be done in UNIX by entering cat filename in terminal interface using keyboard.If we want to repeat the same task of opening the text file hundred times we can pass a script containing the command 100 times.This will save time.
The terminal program mentioned above is called as shell and the technic of passing multiple commands at a time using a script is called as shell scripting.
Now , even UNIX operating systems come with GUI interface but Shell scripting is still the standard way to interact with UNIX operating systems, due to the reason mentioned above.
UNIX systems are dominating operating systems space.UNIX design is based on simple concepts but yet very effective.UNIX is a multi-user,multi-tasking operating system.
Due to these reasons UNIX is the OS on most leading mainframes and on server computers.
UNIX systems are best choice for hosting web applications, where multiple users logs into server at a time and as UNIX is multi-user OS, it takes care of all users requests.Each user can get access with a username and password.Also, same user can access the system through multiple terminals.
As, the increase in web applications , such as flipkart,amazon, use of UNIX systems is also increased.And, UINX shell scripting experts have a high demand.