Teacher: Hey there, folks! How's everyone doing today?
Student: Hey, we're good! Excited to learn something new today.
Teacher: Awesome! Well, today we're going to talk about something really cool in the world of software development and deployment. Have you guys heard of DevOps?
Student: Yeah, I've heard the term, but not entirely sure what it is.
Teacher: No worries! DevOps is like a magic sauce that helps streamline software development and deployment. It's all about making the process smoother and more efficient.
Student: Oh, that sounds useful!
Teacher: Absolutely! And a crucial ingredient in this DevOps magic is Linux, the operating system that's like a superhero in the world of developers.
Student: Linux, huh? I've heard of it, but never really used it.
Teacher: Well, get ready to be amazed! Linux is powerful and versatile, and you'll find it almost everywhere in the DevOps landscape.
Student: So, why is Linux so important for DevOps?
Teacher: Great question! You see, to master DevOps, you gotta be buddies with Linux. It's like the backstage pass to the show!
Student: I like backstage passes!
Teacher: Haha, me too! With Linux, you can navigate the world of DevOps like a pro. It's got all the tools and features you need to make things happen.
Student: Sounds pretty cool, but will we have to become Linux experts?
Teacher: Not experts, but we'll give you the basics and some essential commands to work with. You'll be flying through the terminal in no time!
Student: Terminal? That sounds a bit intimidating.
Teacher: Nah, don't worry! The terminal is just a fancy name for the command line interface. Once you get the hang of it, it's like having a superpower!
Student: I like the sound of that! So, what are we gonna do in this blog post?
Teacher: We'll be exploring some fundamental Linux skills specifically tailored for DevOps. It's like a crash course to get you started.
Student: Can't wait to dive in!
Teacher: That's the spirit! So, let's buckle up and get ready to unleash the power of Linux in your DevOps journey!
Student: Woohoo! Let's do this!
Teacher: Alright, let's get started. You're gonna love this, trust me!
Teacher: First let's understand the Linux architecture
In our Linux environment, our interactions with the application take place through its dedicated window. When we enter a command in the shell, the system, being proficient in binary language, promptly passes the command to the kernel. The kernel, acting as the intermediary between user space and hardware, efficiently converts the human-readable command into binary code and executes it seamlessly. As a result, the desired action is carried out, and we can observe the output on our hardware with remarkable speed and precision. This process exemplifies the robustness and elegance of the Linux ecosystem, where seamless communication between the user, kernel, and hardware leads to a smooth and efficient computing experience.
Teacher: Now let's discuss some basic Linux commands
| Command | Description |
| pwd | Displays the current working directory. |
| ls | Lists files and directories. |
| cd | Changes the current directory. |
| mkdir | Creates a new directory. |
| rm | Removes files and directories. |
| rmdir | To remove a directory |
| cp | Copies files and directories. |
| mv | Moves or renames files and directories. |
| cat | Displays the contents of a file. |
| head | Displays the first few lines of a file. |
| tail | Displays the last few lines of a file. |
| grep | Searches for a pattern in a file. |
| wc | Counts the number of lines, words, or characters in a file. |
| chmod | Changes the permissions of a file. |
| chown | Changes the ownership of a file. |
Discussing a few important tricky questions that can be asked in interviews
- Question: Where are all the user profiles stored in the Linux system?
Answer: In the Linux system, all user profiles are stored in the home directory, which provides each user with their designated space for personal files and configurations.
- Question: In Ubuntu, what does the command "cd ~" mean?
Answer: The command "cd ~" in Ubuntu is used to change the current working directory to the user's home directory. It provides a quick way to navigate back to the user's designated space for personal files and configurations, ensuring seamless access and organization of user-specific data.
This was the interview question that was asked to my teacher, in one of his interview way back.
- Question: In Linux, how can you create 10 files simultaneously using a single command?
Answer: To create 10 files at once in Linux, you can utilize the "touch" command along with brace expansion. The brace expansion allows you to generate multiple filenames with a common prefix and a range of numbers. Simply use the following command:
touch file{1..10}.txt
This command will instantly create 10 empty files named "file1.txt" to "file10.txt" in the current working directory.
- Question: In Linux, what command can you use to access the manual (man pages) for all commands?
Answer: To open the manual (man pages) for all commands in Linux, you can use the "man" command followed by the name of the desired command. For example:
man ls
This will display the manual page for the "ls" command, providing detailed information about its usage, options, and functionality. You can replace "ls" with any other command name to access its corresponding manual page and gain insights into its usage and features.
- Question: In Linux, how can you use the "rm" command to delete a file and its contents recursively, including subdirectories and files within them?
Answer: To remove a file and its contents recursively in Linux, you can use the "rm" command with the "-r" or "--recursive" option. For example:
rm -r directory_name
This command will recursively delete the specified "directory_name" along with all its subdirectories and files within them. Exercise caution when using the recursive delete command, as it permanently removes all data within the specified directory and its subdirectories without confirmation.
- Question: In Linux, what is the difference between the commands "useradd user1" and "useradd -m user1"?
Answer:
| Command | Behaviour |
useradd user1 | Creates a new user account "user1" without creating a home directory. |
useradd -m user1 | Creates a new user account "user1" and automatically creates a home directory with the same name in the "/home" directory. |
- Question: What command can you use in Linux to search for a file within the file system?
Answer: To search for a file in Linux, you can use the "find" command. The syntax for using the "find" command is as follows:
find [path] -name "filename"
Replace "[path]" with the directory path where you want to start the search, and "filename" with the name of the file you wish to find. The "find" command will recursively search through the specified directory and its subdirectories to locate the file with the given name and display its full path.
- Question: In Linux package management, what are the differences between the commands "apt update," "apt upgrade," and "apt install"? Present the information in tabular form.
Answer:
| Command | Purpose | Usage |
apt update | Updates the package index*, refreshing the list of available packages and their versions from the repositories.* | sudo apt update |
apt upgrade | Upgrades the installed packages to their latest available versions. It may remove or install new packages as needed to perform the upgrade. | sudo apt upgrade |
apt install | Installs a new package or multiple packages, resolving dependencies and downloading the required files from repositories. | sudo apt install package_name1 package_name2 ... |
- Question: In Linux Ubuntu, how can you uninstall a package from the system?
Answer: To uninstall a package in Linux Ubuntu, you can use the "apt" package management system along with the "remove" option. Here's the command:
sudo apt remove package_name
Replace "package_name" with the name of the package you wish to uninstall. This command will remove the specified package from your system, along with any associated configuration files, freeing up disk space and ensuring that the package is no longer available for use.