Last updated 10/06/2021
You have heard of Shell Scripting before, right?
The shell script is a computer program or command-line interpreter that is specially designed to be run by the Unix shell.
So the best part about writing a shell script is the commands and syntax are exactly similar to those that were directly entered at the command-line. The programmers don’t need to switch to a totally different syntax, like they would have done while working with a different language, or while using a compiled language.
Writing a shell script happens faster than writing an equivalent code in other programming languages. While working on a shell script, you’ll have added advantages like an easy program or file selection, quick start, and interactive debugging. A shell script also helps in providing a sequencing and decision-making linkage around existing programs, and for moderately sized scripts the absence of a compilation step is an advantage.
Now you understand why Shell Scripting is important in the life of a programmer. Hence, it is only obvious that interviewers will love to question you about it. So, what the Interview questions of Shell Scripting might be? Let’s check that out!
The Shell is a Command Line Interpreter that translates commands entered by the user while converting them into a language understandable by the Kernel. The shell interprets a command typed in at the terminal, and calls the program that you want.
A shell script is a command-containing text-file that contains commands in the order of their execution time. Shell scripts perform several operations like printing text, file manipulation, and program execution.
The two main advantages of shell scripting are:
A shell script has two types of variables :
There are two primary kinds of shells that can be used in a typical Linux system:
Creating a shortcut in Linux can be done through the links present in Linux OS:
Hard Link: They are linked to the inode of the file and must be on the same file system as of the file. If you delete the original file, it does not affect the hard link.
Soft Link: They are linked to the file name and can belong to a different file system as well. If you delete the original file, the soft link becomes inactive.
A SuperBlock is a program that contains a record of specific file systems.
Characteristics of a particular file system like block size, the empty and the filled blocks and their respective counts, the size and location of the inode tables, the disk block map, and usage information, and the size of the block groups can be found in a superblock.
GUI is used to control a computer and its applications. GUI scripting can support different applications and heavily depends on the operating system.
A Linux process generally has four stages:
The break is a simple way to escape out of a loop in progress. Break command can be used to exit out from any loop, including while and until loops.
On the other hand, Continue is responsible for the present iteration of the loop to exit, instead of the entire loop.
The Shebang line is usually found at the top of the script,e.g. #!/bin/sh. This line provides information about the location of the engine. This engine is usually the one executing the script.
Arguments are passed through this command:
#!/bin/sh
ct $1
Arguments can be used with the help of this command:
#!/bin/sh
cp $1 $2
The number of passed arguments can be calculated with this command:
#!/bin/sh
echo "Number of Parameters passed:$#"
To get a script inside a script, you need to use this command:
!/bin/sh
echo "Script Name:$0"
To check the success of the previous command you need to use this logic:
#!/bin/sh
var=$?
if var=0
then
echo "Script was Run successfully"
else
echo "Script was unsuccessful"
fi
To get the last line from a file using the terminal, you need to use this command:
tail -1 <filename>
To get the first line from a file using just the terminal, this following command is used:
head -1 <filename>
To get the 3rd element from each line, we use this command:
#!/bin/sh
awk '{print $3}' $1
#!/bin/sh
function example {
echo "Hello Learner"
}
There are three kinds of loops for Shell Scripting- For Loop, Until loop, and While Loop. Their syntaxes are mentioned below:
For Loop:
for var in word1 word2 ... wordN
do
Statement(s) to be executed for every word.
done
While Loop:
while command
do
Statement(s) to be executed if the command is true
done
Until Loop:
until command
do
Statement(s) to be executed until command is true
done
For its user-friendly nature, Shell Scripting is adored across all the industries. Once you are confident about answering these above questions, you’ll have a number of job opportunities handy. Be it a developer, a cloud admin, an AWS architect, Shell Scripting is useful for all the professions.
Wonder how shell scripting can be applied to the professions mentioned above? Check out our website, apply for the courses suitable for your career choice, and we will teach you all of it!
NovelVista Learning Solutions is a professionally managed training organization with specialization in certification courses. The core management team consists of highly qualified professionals with vast industry experience. NovelVista is an Accredited Training Organization (ATO) to conduct all levels of ITIL Courses. We also conduct training on DevOps, AWS Solution Architect associate, Prince2, MSP, CSM, Cloud Computing, Apache Hadoop, Six Sigma, ISO 20000/27000 & Agile Methodologies.
* Your personal details are for internal use only and will remain confidential.
![]() |
ITILEvery Weekend |
---|---|
![]() |
AWSEvery Weekend |
![]() |
DevOpsEvery Weekend |
![]() |
PRINCE2Every Weekend |