Linux For Beginners | Linux Command for Beginners | What is Linux | Linux Training | Edureka

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Hey everyone and welcome to this video on Linux for beginners. Before we dive into advanced Linux commands used in real world DevOps task, it's important to make sure you're comfortable with the basics. Whether you're just getting started or need a quick refresher, this video will help you set up your environment and practice some essential commands. Before we begin, please like, share, and subscribe to Edureka's YouTube channel and hit the bell icon to stay updated on latest tech content from Edureka. Also, check out Edka's DevOps training program, which is designed to equip learners with the skills to master AI integrated DevOps across the entire software delivery life cycle. Through hands-on learning, you will gain expertise in building intelligent, automated, and secure CI/CD pipelines. This comprehensive course covers essential tools like Git, Genkins, Terraform, Enible, Docker, Kubernetes and monitoring frameworks while also integrating AIdriven solutions for code generation, testing and analytics. Do check out the course link given in the description box below. Now let's jump right in. Let's take a quick moment to understand what Linux actually is and why it is so important for DevOps. Linux is an open-source operating system. similar to Windows or Mac OS. But here's the big catch. Linux is free, customizable, and it powers the majority of servers, cloud systems, and DevOps pipelines across the world. Why this is important? In fact, most of the internet runs on Linux. Web servers, databases, cloud providers, and tools like Docker and Kubernetes all rely heavily on Linux. That's why DevOps engineers, system administrators, and cloud professionals must be comfortable with Linux commands. They let you directly interact with the system, troubleshoot issues, and automate tasks. So now, first let's talk about how to move around in the Linux terminal. These commands will help you navigate your file system. So let's get started. So here you can see this is my Linux terminal. Great. I'm going with my first command which is pwd. Well, pw stands for print working directory. So, this shows you where you are right now. So, it shows me I am into home and I'm into edureka. Great. Now I will go with the second command which is ls which means list. So this lists all the files and folders in the current directory. So my directory was adure and these were all the directories you know files and folders in the present directory edurea. Great. Now there is a third command which is known as cd. cd actually means change directory. So now if I want to go inside any of these I will go by this command only. So let's see if I want to go into documents. So I will print cd documents enter. Now if you can see this slash and documents it means you're inside the documents. Now let's try and again print our working directory what it is. Let's see pwd. Now it is showing me that I'm inside the home inside the edurea inside documents. Nice. So with these commands you can easily move through your file system and see what is inside. Let's go one step further creating and managing files and directories. Let's learn how to create, copy, move and delete files and folders. So let's go for our first command which is mkdir. So what does mkdir means? It means make directory. Let's choose the name for the directory. Let's suppose my project. Now if I'm entering it, it will create a new directory called my project. Let's see. So this is my documents folder. I'm into home edure documents and see my project is created. Right. Let's go one step further. Now I will go inside my project. So how will I be going? I said you above also cd. Let's go cd my project enter. See I'm inside. Before go for the first command I just show you that there is nothing inside my project right now. Now I will be using my third command which is touch. Well simply means it will create a empty file. So for creating an empty file you will use the command touch. Now I will name the file which is index dot html for an example. Enter. Now it has been created. Let's see it is there. So without coming over here with the help of terminal I created index.html. But what if I don't want to go to file manager to check whether it's created or not. I will use the command ls. See it will list all the files and folders over there. index html. Now let's suppose I want to do the copy of this index html. So I will be writing cp which means copy index.html and by what name I want to copy it. Let's say backup. So I will say backup html. Enter. So it will actually create a backup file of index.html. Copy paste basically because I'm into the directory of my project only. So it will create the backup over there means my copy file over there. Great. Let's go to next command which is mv. So basically mv command is used for renaming the file. Let's say I want to change the name for backup.html. I will be using mv backup dot html and I want to say change it by index backup html. So it had been changed. See index backup html. Before it was just backup html. Now it is index backup.html. This is how we rename the file. Now what if I want to remove or delete the file? I will be using rm command. So rm I want to create the backup file. So I will be deleting index backuph. So by entering it I actually deleted the file. You can see over here it has been deleted. So this is the power of terminal. So these commands are the building blocks when working with the files and folders. You will use them every day in projects and deployments. So now let's view the files. Sometimes you will want to peek inside a file to see its content without opening it in an editor. So how you'll be seeing it? So I'm going time to time over here checking whether it is there or not. What is inside index html. What if I will say that you can do by the terminal itself. Right? So there is a command cat which actually means print the entire file content. So cat index.html HTML by entering it you will actually print the entire file content. So there is nothing over here in the file right now. Now there is a next command which is known as less index.html which means view the file with scrolling. How it will works? Let's see. Enter. So if there is something inside index html you can see over here right. So now how do I get outside of it? Well, there is a command over here which is known as Q. You have to just press the button Q. It will quit. It will get back to your terminal. There's another command which is known as more. Well, it is similar to less but simpler navigation. So these is all the command for viewing the files. These are perfect for quickly checking logs or configuration files so that you shouldn't go inside the file manager again and again and see whether it is there or not. Now next step further managing permissions. Linux is a secure operating system. So permission matters. Let's see how to control and who can access or modify files. So here are two commands which you have to put in your mind. So first command is ch OD. Basically chmod is used for change mode. So I will be using it. 644 I want to use for index.html. So this sets the file so the owner can read and write while others only can read it. So if I am the user and I am the owner of it, I can only read and write. I can do whatever I wish to. But if someone else want to do the same, they want to seek the permission with me. They can only read it with this command. I can do that stuff. Now let's go to another command which is ch Own. It means change the owner. So for example, I'm into edua right now and I want to change the owner for index.html. So with this command I can actually change it. So permissions help keep your environment secure especially when working on shared servers. So it is very essential for that time. Getting help. Don't worry if you forget how a command works. Linux gives you ways to explore commands anytime. So there is a command man ls. So by entering it you can open the manual for the ls command showing options and usage. So author what it will be doing block size ignore backups and everything over here. So this is how you can see it and how you can learn it by your own. And there is one more command which is known as ls help. So a quick summary of how to use ls. So you can read this documentation for your better enhancement. Now let's go further. So using man or help will help you become more independent and confident when learning new commands. Let's put this into practice step-by-step demo. Okay. So to navigate out of your current directory in Linux, you use the cd command, right? But moving out of your current directory and going to your parent directory, you will use cd space full stop full stop. So for example my current directory is my project and I want to go my parent directory which is documents. I will be using cd space full stop full stop. So by this I'm again back to my parent directory which is documents. So let's put all of this into practice. So stepby-step demo once again. Okay. So for creating a directory or a folder I will be using make directory. Let's go for test. Right now I have created the documents. I have created the directory test inside the folder documents. Let's see over here. So this is documents and there is test over here. Right now I want to go inside the test. I will be using cd test change directory. Create a file. So touch uh let's say app.log. Now I will be checking the contents. So there is only app.log which is file over there. Now I want to view the file. So I will be using cat app.log. Now if I want to go to my parent directory, what will be using? CD space full stop full stop. Nice. Now I want to remove. So I will be using rm r test test. So it will actually delete the folder. So let's see now there is no folder over here because I have deleted it. So with just a few commands you can set up files, explore them and clean up all essentials for any DevOps workflow. Now that you have practiced these basic commands, you are ready to learn how Linux commands are grouped by functionality and used in real DevOps scenarios like monitoring logs, troubleshooting networks, and automating deployments. In Linux, there are hundreds of commands, but memorizing them without understanding where and when to use them can be overwhelming. That's why structuring them by use case and functionality makes it easier to learn, practice and troubleshoot task in DevOps pipelines. So let's break down into practical groups. So file and directory management. So there's a command for that which is ls cd pwd mkdir rm cp mv touch find and gr. So these are the commands you will use daily to navigate, organize and manipulating files and directories. So imagine you want to search for configuration files and containing a specific keyword inside your project directory. You can combine find and gr like this. So for example, if I want to do the same, I will be using like find let's suppose etc. Well, this is just an example so it will not work. etc hyphen type f - name apostrophe and star dot cf apostrophe e x e c execute g r e p- h listen forward slash Enter. So this helps you quickly locate settings that need tweaking. So let's go to our second thing which is process and system monitoring. So there are commands for this which is PS top ed stop kill all uptime free VM stat IO stat l sof dme sg. So these are all the commands which is used for process and system monitoring. So when systems go down or slow these tools help you diagnose what is happening under the hood. So for example to monitor a process in real life you can use stop or to more interactive version you will use edge stop. So you can spot memory hungry processes and safely kill them using kill. So let's go further. For file viewing and manipulation, you'll be using cat, head, tail, less, more, awk. So parsing logs, reading files and filtering information is essential when debugging deployments or performance issue. So let's take a scenario to monitor verification logs for errors in real time. You will use tail so that this will continuously stream log entries containing the word error. Now the step four which is user and permission management. For that we will be using sudo chmod change mode pa sswd add user user delete user mode groups ID. So this will managing user permissions is critical to secure infrastructure right. So to allow a user or a permission management we'll be using these commands. Now there is example scenario to allow a user to run commands with elevated privileges. You can use sudo su because I'm a super user user mode hyphen a capital g docker deployer. Now see these adds the deployer user to the docker group so they can run containers safely. So here you can see there's a command there is a login section shell section it's basically your firewall how you are protecting it and how you can do it the same network and connectivity. So there are various commands for that. For example, ping, if config, you can also use IP config that is also same net stat, SSH, SCP, R sync, wget, curl, NC, trace route, NS lookup. So these are all the commands for using networking and connectivity. Network issues can cause downtime. So having the right tools to diagnose and fix problem is a must. Let's clear it all. So there's a scenario for the same to check if a server is reachable and measure the roundtrip time. So I will be using ping - c for example.com. See this is working. Let's terminate it right now. And I will be using let's suppose google.com and it is pinging to google right now. Right. Okay. So it has been done. So it has been transmitted and received 100% packet loss and how much time it has been taken. So I'm pinging from which IP address it is showing that. So this is how you can actually ping or to trace the path packets. So I will be using same thing I will be going to google.com and I will be using trace route to check how it has been done. trace route google.com. So actually I have to install everything and I want to go with the stuff. So by installing the trace route I can actually see how to trace route everything and how can I choose the path in which IP address it is going and where it is coming right. So it will help you how to isolate when the connection is failing. Now let's go to the sixth step which is package and service management. So there's a command a yumm system ctl and journal ctl. Installing software and managing services is a part of automation and system maintenance. So these commands will help you in all of that. Okay. So let's clear it. Okay. So let's take a example scenario. You have to restart a service like during a deployment. So what will you use? You will use sudo system ctl restart engine fail to restart because it is not installed right now. So it is basically a purpose like how do you use pip install python pip install any of the services in python or you know pyarch if you have used that. So it's basically like that. Okay, great. And to check logs, you will use pseudo journal ctl. These help you troubleshoot issues after deployment. Let's go to the next part, which is security and firewall. For that, there is a secure shell, SSH, SSH, key gen, IP tables and SSH agent and etc. There are a lot of things inside the security and firewall. Security is crucial in any of the production environment for generating a SSH keys to secure authentic to your servers. What command you will be actually using it. So you will be using SSH key gen key generation basically - T RSA - B 4096. So it will be generating a public or private key and it is asking me for which file I want to create. So I'm saying for index.h HTML. So it is asking me for any phrase if I want to give or pass phrase. What will be the passcode for the same? So I'm just typing it hello enter because it's a password so it will be not visible. Now if you can see index html is saved and I have to use the password which is hello to open it. So this ensures you can access servers without exposing passwords. Right? So miscellaneous and automation which is used like commands lis history to check your history by the word itself says that date echo sleep watch reboot shutdown and there are a lot of another examples for that another commands for that you can just read the documentation for the better enhancement of yourself. So these are useful for scripting and simplifying repetitive task. So let's take an example. So to repeatedly check CPU usage every 5 seconds what I will be writing watch because I want to see right and I want to say for 5 seconds and top B and one. So it is showing me how it is working right now and it is changing in every 5 seconds. See and another 5 seconds it will be changing it. So this is how you can have to work upon it. Great. So for getting outside of it you will be using control C to get out of it. So to help your monitor system held during high load testing you will be using these commands. Let's clear it again. Now real world DevOps scenario. So let's tie everything together with some practical examples that you will encounter in DevOps workflows for monitoring logs for errors. What you will be using? Use tail/hub with grap. You can catch errors as they happen helping you act fast before an issue escalates. So let's see example tail slashf space v log system log using get grap over here to check is there any error or not. So checking error and there is no files remaining over there because permission has been denied for reading it. So this is basically a purpose and how you can find it out for automating deployment. You can actually use rs sync. Well using rsync is to copy files between the servers. For xyz server to abc server what you will be doing you will be just writing r sync ab building a server like ad server. My server is k master for right now. So at the rate km master and/w whichever I want to go for. So this is how you can automate the deployment with the help of r sync. So manage services in CI/CD pipeline for restart services after deployment you will be using systemctl okay for checking the service status what you will be typing pseudo system ctl status my service so it will actually look for the status so this is a step in automation pipelines to ensure services are running or not for network troubleshooting which I told you before also so using ping and trace route you can actually find connectivity issues so you can see where packets are delayed or dropped and fix them accordingly. So with this we have come to the end of this video on Linux for beginners. If you enjoyed listening to this video, please be kind enough to like it and you can comment on any of your doubts and queries. We will reply to you at the earliest. And do look up for more videos and playlist and subscribe to Edureka's YouTube channel to learn more. Thank you for watching and happy learning.