Unix Shell Scripting Interview Questions
Unix shell scripting is an efficient and flexible method for automating tasks and administering systems.
Written through command-line interface scripts, shell scripts allow users to execute anything from basic file management tasks to more intricate system administration activities.
This blog will outline the basics of Unix shell scripting and Unix shell scripting interview questions for experienced are likely to encounter during job interviews.
1. What are Linux shells?
Linux shells are interpreters that act as a bridge between the kernel and the user, they interpret user input and execute programs based on it.
2. What is a shellscript?
A shell script is a series of commands written in a shell language that can be interpreted and executed by the shell.
3. What are the different types of shells in Linux?
Some of the different types of shells in Linux include the Bash shell, S H shell, con shell, KSH shell, POSIC shell, C shell distributions, and TCSL.
4. What is the most famous and secure shell used in Linux today?
The most famous and secure shell used in Linux today is Bash.
5. How do Linux scripts and programs differ?
Programs are executable files that may run without a shell, while scripts are shell language commands.
6. In Linux, how do I make a shell script?
In Linux, you can use a text editor like VIM or nano to make a shell script, you will need to make a new file, type in your commands, and save it with the.sh name, the script can then be run by typing its name, then a space, and hitting Enter.
7. How do I make a shell script executable in Linux?
To make a shell script executable in Linux, you can use the chmod command followed by the word “x” to add execute permissions to the script file.
9. What is the function of the shebang in shell scripts?
The shebang is a pointer to the interpreter used to run the script, it is significant in a shell script because it instructs the operating system which interpreter to use to execute the script.
10. What is the “echo” command in Linux?
The “echo” command in Linux is used to print text to the console, it can be used to display messages, variables, and other information.
11. How can a user input be stored in a shell script?
Using the read command to prompt the user for input and save it to a variable.
12. What is command substitution in shell scripting?
Command substitution allows the storage of output of certain commands into a variable, allowing for proper printing of data.
13. Can variables be assigned using operators or variables in shell scripting?
Yes, variables can be assigned using operators or variables to store and assign values.
14. What is the distinction between a Bash script and a Shell script?
A bash script is a form of shell script in which the Bash shell serves as the interpreter. Bash is the most common and secure shell used in today’s Linux distributions, and it is recommended for all scripting lessons.
15. How can mathematical operations be performed using variables in shell scripting?
Mathematical operations can be performed using the let command, and variables can be used to store and operate on the results.
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For math processes, you use double brackets, for pattern matching and string manipulation, you use square brackets.
17. Can a shell script be made more efficient and effective by storing commands inside variables and then printing them?
Yes, storing commands inside variables and then printing them can make the shell script more manageable and effective.
18. What is the for loop in programming?
The for loop is a powerful tool in programming that can be used to execute tasks in iteration for a list of subjects, it can be used to store a series of values, an area or sequence, and is useful in shell scripts where a list array needs to be listed and executed.
19. What is the until loop in programming?
The until loop is another loop that performs similar functions as the for loop but with different utilities, in this example, the loop increments the variable by 1 until it is not less than 10, then skips lines and comes to the end, the loop continues until a certain condition is met, and it goes to done.
20. How do while and for loops vary in programming?
While loop works till condition is met, for loop has array, and until loop works until condition is met, the Bash script has an until loop, however some shells block it.
21. What is the select loop in shell scripting?
The select loop is a crucial part of shell scripting, providing a user with an option to select a drink from a list of conditions, this loop is specific to Bash and can be used in various cases, such as giving a menu to the user and based on their selections, providing outputs.
22. What are file operators in shell scripting?
File operators are expressions used to check file sentry entries, they are used to check if a directory exists or not, if a path is a file, and if the path is a directory.
23. What is the role of the echo command in shell scripting?
The echo command displays text on the screen, it can display a message, a variable, or the output of a command.
24. When writing scripts in shell, why do you need an if loop?
One way to make judgments in a shell script is using the if loop, which is a conditional statement, if a condition is true, it executes one block of code; if it is false, it executes another block of code.
25. What is the use of the else if statement in shell scripting?
The else if statement checks various conditions in a shell script, if the first condition is not met, the script moves on to the second requirement.
26. What is the minus function used for in shell scripting?
When writing shell script, the minus operator is used to see if a file or directory name already exists, the file or directory is found if the condition is met. If it is not met, the file or directory is not found.
27. What are the functions of the hyphen D, E, and F operators in shell scripting?
In shell scripting, these operators are used to determine whether a file or directory path exists, the hyphen D operator determines whether a directory exists, while the hyphen E operator determines whether the path is a file or a directory.
28. Why is the ETC hosts variable in shell scripting used?
Shell scripting stores file or directory paths in the ETC hosts variable, the minus operator checks file or directory existence.
29. Why is the dollar hash used in shell scripting?
The dollar hash shows shell programming mistakes, option A returns errors, option B returns command line parameters, option C returns error, and option D is inapplicable.
“Unlock the Power of Unix Shell Scripting with MCQs!”
1. What is Unix?
a. Graphical operating system developed by Microsoft
b. Command-line operating system developed by Linus Torvalds
c. Mobile operating system developed by Apple
d. Web-based operating system developed by Google
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a. Windows
b. macOS
c. Android
d. Linux
3. What is the primary command-line interface for Unix-based systems?
a. Windows Command Prompt
b. macOS Terminal
c. Android Command Line
d. Linux Command Line
4. Which of the following is a popular text editor used in Unix-based systems?
a. Notepad
b. TextEdit
c. Sublime Text
d. Vim
5. What is the function of the shell in Unix-based systems?
a. Execute programs and commands
b. View file system hierarchy
c. Manage user accounts and permissions
d. Display system information and diagnostics.
6. What is an Unix shell?
a. Operating system
b. Computer hardware.
c. User interface for Unix operating system
d. Programming language
7. What is the most commonly used Unix shell?
a. Zsh
b. Tcsh
c. Bash
d. Fish
8.What does “cd” command do in a Unix shell?
a. Changes the current directory to the specified directory
b. Creates a new directory
c. Deletes a directory
d. Updates the current directory listing
9. What is the main function of Unix shell scripting?
a. Develop graphical user interfaces
b. Automate chores and processes.
c. Create games or simulations.
d. Manage files and directories.
10. Which of the following is a common command used in Unix shell scripting to redirect output to a file?
a. cat
b. echo
c. redir> filename.txt
d. all of the above
11.Why use variables in Unix shell scripting?
a. Data storage and manipulation
b. Loop creation
c. Conditionallyoperate
d. Create arrays
12. Which of the following is a common file extension for Unix shell scripts?
a. .sh
b. .py
c. .java
d..csharp
conclusion
Unix shell scripting is a complex and specialized skill that requires a deep understanding of the underlying concepts and commands.
Unix shell scripting interview question and answers for experienced candidates must be able to solve complex problems, troubleshoot issues, and write efficient scripts.
By preparing for and acing interview questions related to Unix shell scripting, candidates can demonstrate their expertise and increase their chances of landing a high-paying and challenging job in this field.
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