Introduction to Korn Shell Scripting
The korn shell scripting is coming under the UNIX shell scripting. It is also called the command execution program. It was developed by David Korn. It is the inclusive version of the all UNIX shell. It is a nice combination with the C Lang and the tcsh. It will provide nice support like the Bourne shell scripting. In the UNIX environment, korn shell scripting is the most effective shell scripting language. The korn, C and the Bourne shell scripting is the most popular shell scripting language in the UNIX environment.
In the UNIX platform, the korn shell scripting considers a Bourne shell family member only. Therefore, the korn will use the same shell prompt as the Bourne shell. To work with it, we need to use the ksh keyword. The ksh will accept the program and command from the input terminal as well as the in the form of the shell file.
Why we Need Korn Shell Scripting?
- The korn shell scripting provides the rich function for the scripting utility. It works in interpreter format. It means we need to provide the set of commands into the Korn shell file. Then the interpreter will interpret the command and directly execute it. So it is faster than the normal compiler process. In the compiler, it will take the command then it will compile it. Once all things will be good, then only it will process further. But in the korn shell scripting, there is no concept of the compiler; it will process the command directly with the help of an interpreter and execute it. Hence the shell scripting is more power full as compared to the compiler.
- It is the combination of the C language and the Bourne shell scripting. Hence we can use the C Lang as well as the Bourne shell functionality in the korn shell scripting. It is having great community support. We can use it in the commercial environment also. As per the need or application requirement, we can also use the korn shell scripting in the production environment. In it, we are getting the rich support for control statement, variable declaration, use the different and multiple operators, array functionality, recursive access, function, data redirection, looping, branching, command-line arguments, pipes functionality, coprocesses, trivial calculation, complex numerical calculation, etc.
How does Korn Shell Scripting Work?
- The korn shell scripting, we are using run the script programs. In the script file or program, we are having the set of commands in it. While running the Korn shell, every command which is available in the file will split into different components.
- Every slip of the command, it is having a specific meaning in the korn shell scripting. Therefore, it will execute line by line.
- If all things go well at the end, then the execution control comes out, and the script file or the program will be complete.
- But if any error or wrong statement will come in it. Then the interpret control will trigger an error, and the control comes out from the execution loop.
Advantages and Disadvantages of Korn Shell Scripting
Given below are the advantages and disadvantages of Korn Shell Scripting:
- Job control: We can control the job with the keyword fg and bg commands. It will keep the job in the background as well as in the foreground. If we need to stop the jobs, then we need to use the CTRL-Z option.
- Aliases: With the help of the aliases, we need can define the shortcut names for the commands. Hence, we do not need to write long and complex commands.
- Functions: We are having the functionality to use the C shell. It will help to increase the programmability. In addition, it will help to store the variables in memory rather than the file.
- It will provide a good Command history. In addition, it will help to recall the previously entered commands.
- In it, we are having multiple options like emacs style editing command, Command-line editing, which will allow us to use the editing tool etc.
- It will allow the integrated programming features also. Due to which it will provide the functionality of work with several external UNIX level commands. It will also include the getopt, test, echo, expr, etc. It will provide rich support to shell jobs or shell scripting. It will enable common programming tasks without creating multiple subprocesses in the current working environment.
- It will provide the rich support for the control structures also. Majorly for the select construct, it will help for the easy menu generation.
- It will help for the debugging primitives. In addition, it will help to write the multiple tools that will for the developer to debug the shell codes.
- In it, we can use regular expressions also. So, for example, we can use the expression which is using in the UNIX environment like the grep, awk, etc.
- It is having advanced input and output features. It is also having the ability for two way communication also. In some cases, we can establish continuous communication also.
- In it, we are having multiple new options and variables. In addition, it will lead to having more ways to customize the environment variables.
- It will help to increase the speed of the shell code execution process.
- It is also having rich functionality available for the security features. It will help to protect from the external virus, etc.
- It is not having the much standard scripting features.
- We are not able to install it in everywhere (as per the default state).
- Need to install the packages, not come with the default standard package suit.
We have seen the uncut concept of the “korn shell scripting” with the proper explanation, working strategy. It is the combination of C land and Bourne shell. It is having rich support for the shell scripting functionality.
This is a guide to Korn Shell Scripting. Here we discuss the introduction, need, working, advantages and disadvantages of Korn Shell Scripting. You may also have a look at the following articles to learn more –