Best reasons to learn shell script

Today, we are going to discuss Shell Script and find out the reasons - why you should use Shell Scripts.

What is Shell Script?

A shell script is a text file that contains a sequence of commands for a UNIX-based operating system. It's called a shell script because it combines into a "script" in a single file a sequence of commands that would otherwise have to be presented to the system from a keyboard one at a time. The shell is the operating system's command interpreter and the set of commands you use to communicate with the system. A shell script is usually created for command sequences for which a user has a repeated need. You initiate the sequence of commands in the shell script by simply entering the name of the shell script on a command line.

The various dialects of shell scripts are considered to be scripting languages. Typical operations performed by shell scripts include file manipulation, program execution, and printing text. A script which sets up the environment runs the program, and does any necessary cleanup, logging, etc. is called a wrapper.

In the DOS operating system, a shell script is called a batch file. In IBM's mainframe VM operating systems, it's called an EXEC.

Somewhat common shell is Osh, whose manual page states it "is an enhanced, backward-compatible port of the standard command interpreter from Sixth Edition UNIX. Related programs such as shells based on Python, Ruby, C, Java, Perl, Pascal, Rexx &c in various forms are also widely available.

So, why do use Shell Scripts?

• The biggest advantage of writing a shell script is that the commands and syntax are exactly the same as those directly entered at the command-line. The programmer does not have to switch to a totally different syntax, as they would if the script were written in a different language, or if a compiled language were used.

• Writing a shell script is much quicker than writing the equivalent code in other programming languages.

• Combine lengthy and repetitive sequences of commands into a single, simple command.

• Generalize a sequence of operations on one set of data, into a procedure that can be applied to any similar set of data.

• Create new commands using combinations of utilities in ways the original authors never thought of.

• Simple shell scripts might be written as shell aliases, but the script can be made available to all users and all processes. Shell aliases apply only to the current shell.

• Wrap programs over which you have no control inside an environment that you can control.

• A shell script is used to analyze performance in real-time. Monitoring a network or system will inform you whenever an issue is detected.

• It helps to avoid network problems. It can also be used to solve a system failure quickly.

• Create customized datasets on the fly, and call applications (e.g. Matlab, sas, idl, gnuplot) to work on them, or create customized application commands/procedures.

• Rapid prototyping (but avoid letting prototypes become production).

• System boot scripts (/etc/init.d).

• System administrators, for automating many aspects of computer maintenance, user account creation etc.

• Application package installation tools.

• Application startup scripts, especially unattended applications (e.g. started from cron or at).

• Any user needing to automate the process of setting up and running commercial applications, or their own code.

• Non-expert users can use scripting to tailor the behavior of programs, and shell scripting provides some limited scope for multiprocessing.

• To make a program run faster, you’ll need more memory. Finding a free memory will be easier with the use of Shell Script.

• It makes coding easier and helps you to focus and relax while coding.

• You can easily found hidden programs that are eating up your system. By using Shell Script, you can identify what processes consume your available system resources.

• Use the shell script to secure all vital information and data. You can easily back everything up. Such as important files.

 

A shell script has syntax just like any other programming language. If you have any prior experience with any programming language like Python, C/C++ etc. it would be very easy to get started with it.

 

Just tell us what do you think about the Shell Script. You can also share your valuable comments with us in the comments below. Thank you!