Linux for Cloud & DevOps Engineers | AR Shankar | Skillshare

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Linux for Cloud & DevOps Engineers

teacher avatar AR Shankar

Watch this class and thousands more

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Taught by industry leaders & working professionals
Topics include illustration, design, photography, and more

Watch this class and thousands more

Get unlimited access to every class
Taught by industry leaders & working professionals
Topics include illustration, design, photography, and more

Lessons in This Class

36 Lessons (3h 57m)
    • 1. L1 - Linux Introduction

    • 2. L2 - What is Operating System

    • 3. L3 - Create an AWS account

    • 4. L4 - Create an Linux EC2 Instance

    • 5. L5 - Connect to a Linux server using Mobaxterm

    • 6. L6 - Connect to a Mac

    • 7. L7 - Linux Filesystem Hierarchy

    • 8. L8 - Linux Basic commands - Commands: date, cal, uptime, whoami

    • 9. L9 - Read a File - Commands: cat, more, less, head, tail

    • 10. L10 - Creating files - Commands: touch, cat, vi

    • 11. L11 - Edit or Append Content to a File - Commands: cat, vi, nano

    • 12. L12- Create Directories - Commands: mkdir

    • 13. L13 - Remove FIles and Directories - Commands: rm, rmdir

    • 14. L14 - Copy Files or Directories - Commands: cp

    • 15. L15 - Move or Rename a File - Commands: mv

    • 16. L16 - Changing Directories - Commands: cd

    • 17. L17 - Search a File - Commnds: find, diff and file

    • 18. L18 - Search for a Word in a File - Commands: grep

    • 19. L19 - Replace a Word in a File - Commands: sed

    • 20. L20 - Creating & Managing a User - Command useradd

    • 21. L21 - Login as a User onto EC2 Instance

    • 22. L22 - ls Command Explained

    • 23. L23 - File Permissions

    • 24. L24 - Changing Permissions - Commands: chmod

    • 25. L25 - Changing Ownership - Commands: chmod, file

    • 26. L26 - Gather System Information - Commands: free, cpuinfo, uname etc..

    • 27. L27 - Installating packages - Commands : yum [install, remove]

    • 28. L28 - Updating and getting info about pacakges - Commands: yum [update, list, info]

    • 29. L29 - Collect Network info - Commands: hostname, ping, wget, ifcofnig, curl

    • 30. L30 - Telnet explained

    • 31. L31 - Services - Commands: service [status, start, stop]

    • 32. L32 - Services - commands chkconfig, systemctl

    • 33. L33 - Process Management - Commands: ps, fg, bg, top

    • 34. L34 - Archiving files and directories - Commands: gzip, gunzip, zip, unzip, tar

    • 35. L35 - Crontab

    • 36. L36 Link Files

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About This Class

As you all know in the current IT market Linux became a pre-request to learn most of the trending technologies. IT industry also uses Linux as there base Operating System in the majority cases. Hence this course helps you to understand how Linux works from basics. Once you learn complete this course you can able to

Fulfill your regular tasks on the Linux server

Easily start learning most of the trending technologies like AWS, Azure, GCP, DevOps, Python, BigData, DataScience, etc..

Meet Your Teacher

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AR Shankar


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1. L1 - Linux Introduction: Hello, friends. Welcome to my new course, Lennox for Cloud Under the Webs in Venice. I'm so much exited to share my Lennox of skills with you, even though I named my course as Lennox for Cloud Under Develops in minutes. I also can say that the Lennox for beginners let's see who can handle for this course. People who are sifting from 90 background toe 80 baghran. Obviously they must learn Lennox if they want to work on any training technologies at this moment who is not working on in exile in explode from so far under your fresher Who is deserted toe work on I d industry Before diving into the courts, Let me introduce myself. My name is J. R. Shankar. I helped in place yourself i d experience. Currently I am working at that develops consultant in leading I t company. I'm working on technologies like develops irritably is on the UNIX are this moment I'm teaching 19,000 plus students are new to me platform alone. Now let's see how it is going toe add value toe you were carried. You can ableto fulfill irregular tasks which you want to work on Lenox operating system and Lennox became your prerequisites to learn most off the new technologies. At this moment, if you come under to this category, of course you can handle for these courts. I hope I can to you in the course. See you in the next video. 2. L2 - What is Operating System: Hello, Prince. Welcome back in this lecture, we're going to see what is operating system. If you are already aware off this concept, please ignore this lecture. Let's see the definition off operating system operating system is an interface between user under the computer. Harville. As you know, you cannot able to speak directly to the computer because computer can understand only binary language. Which means Giron. Once you cannot speak the same language, right, that is weird. We need someone who can help our convert our requests in tow. Binary language. That person name is operating system. Let's see, how does it work if you user directly communicating with the hardware that request, go to the hardware part. Your hardware says that I don't know what you are talking that is, really we need operating system Now. You can send your request to the operating system because operating system can understand what you requested, and then it sends to the hardware and it killed the response again to operating system, and it processed er response to you, where you can understand what is the rest wants. That's how it works. Now let's see what Colonel operating systems are available in the market. We know Windows on Mac Way says yet IBM Yeah, X hitch Buicks. So Lorries Lennox. So these are the mostly used operating systems in the market again under Lennox, we How different operating systems. Those are redhead Lennix, Ubundu, Lennix, Fedora, Soucy, Davey in central areas on so on. Like this. We have 200 place operating systems under Lennox flavor because those are derived from that Lennox. Now you may ask that I'm more using Windows and wear six, but not the Lennox. Where exactly does it useful? If that is ever question, you need to understand how you access your application from your computer. Let's take a scenario that you are accessing some applications. A that from your laptop are mobile. Phone our desktop. If the application runs on your wound system off course, you knew not to connect to Internet. But if the application is not running on your local system, you need to connect to the Internet in dinner. Send the request to the server where application is running, so application take you What request? Process it on. Send the request back now. If you see here these systems, we called as a client systems on most of the cases. We are using claimed operating systems over here, But whenever it comes to the server operating system, Lennox is the widely used to server operating system. That's why you might not work with Lennox more. But whenever you joining any organisation and if you start to deploying some applications, that is where you can see the power off. Lennix. So do we really need a server to install an X operating system? No, we don't need even we can install on our laptop. Are desktops No to learn Are to start with the Lennox. How can I get your system now? There are different ways you can progeny Olynyk system that is you can directly installed in exploits on your laptop or a desktop For this unity of Syria, which contains the Lennix wears installed being were on Windows System and creative IAM. You can install the ember software and then you can create a virtual mission. Under William were application Adel's installed virtual box under creative Virtual Mission . This is also similar way we need toe don't Lord virtual box. Then create a virtual mission and ah you conclusion you Lennox William Unclothed here I'm going toe pro genia Lennox for human clothes because competitively, remaining options. This is the easiest tomato start. So I'm going to create a Lennox William Onion, a blues club hotel. Create a leading serve. Honorably is clothes we are going to see in the next video. Thanks for watching. See you in the next video. 3. L3 - Create an AWS account: Hello. Friends will come back in this lecture. We are going to see how to create an ear oblivious free Tyra current as a disgusting over previous lecture we knew the A near Nablus are contratos set up our Lennox server. Creating any Arab Lisa count is also helpful for you. If you are using AWS or develop services in the letter parent off time. Now let's go and see. How can we set up? You need a place account open Google Page under type for a terribly street American. The first page itself shows us that terribly. Start imagine dot com free click on this here you have your option to create you three account. Let's create it here. Probably humility and possible under the Arab Lisa continent continue to create Next you can choose whether it is your professional counterparts. Melancon In my case, I'm leaving it as a professional account. You can change it toe the personal if you're creating for your wounds. I help provided my information over here. In your case, you should feel with your information. Then click here and create a continent continues here you need to provide. They were creditor. David Gordon permission to proceed further. I help provided my card in permission and you can probably where? Pan card or details if necessary. Then click on verify Under add. Now they are going to validate. They were card by directing ₹2 in Indian currency. If it is other country, they are going to predict according to their local currency. I'm providing my OTP and submit it is very freeing my payment information Pretty is valued one. It takes us to the next page. Next thing is confirm your identity. Now we need to provide our phone number so that they are going to validate with other text . Mrs. R y skull, I'm in India so country and reason name is place Name one. I have given my mobile number and send SMS rather than what is called. Now I'm going to receive your four digits verification called. I need to provide here to validate verify court. Okay. My identity has been verified successfully and continue now We came toe the selective support plan Pace Let me increase foreign Saiz here AWS offers three type off plants That is basic plan development plan on business plan. If you go to their development plan You can see the water nail options you are going to get . They will give technical support And if you go for business plan even here also you are going to get technical support. But the response could be quicker than the doll of men plan in basic plan They don't give any technical support. But for us it is learning purpose. Let's create a three day rock on. We have created our AWS account. If you would like to share what role on the interest of it terribly ists, then you can provide this information other ways. You can go here on choose AWS management console now we can credibly assigning pace We are going to use root user We should provide our email early to log into account. If you don't have a constant, you can create it from here by choosing option called creating a new irritably s account I helped provided my humility. Next I'm providing my password on signing No, I have logged into my ear oblivious council And if you want to see all services, you can click over here. But among these many services we are going to use only one service for our Lennox practice . That is easy to service under compute. So let's click over here. If you see here, our account is not here to activated fully because we might be missing one or two steps. I know that I haven't validated my email. Idiot. They are going to send Ian verification humility to our account of it in 24 hours. But usually they don't take much time. I might. How? The Syrian email from here. Ablaze. By this time, let me log into my Gmail account on the check it out. If you see here, I have received a two emits from Mirabilis. When is welcome to Ed oblivious Web services. Another oneness ever account is ready. Let me see what is here. And they are asking me to click here to access my account. Let's click here. Okay, this is building Dashboard Onda. Let's go too easy to service. All right now I could able to access my easy to services so it means that my account is activated. No. Now we can create easy to instances from here Ho to progeny. Lennox is a two instance We are going to see in that next lecture. Thanks for watching. See you did it 4. L4 - Create an Linux EC2 Instance: Hello, friends. Welcome back in this lecture, we are going to see how can we create young Lennox? Easy to instance, before creating any instance Let's see the limitations were Do we help with the free tire account? I'm in the AWS free Terra contemplate. If you scroll down, you can see the Frito Eligibility is We are mostly concentrating on the computer services where we launch easy two instances. So imagine easy to instance we can use 7 50 hours per month, which is equal to 30 days. If you're running an easy two instance without bringing down like this, they're going to give for 12 months free trail. Moreover, if you are not using, you're easy to instance you can shut it down on. You can say these 7 50 hours to it lays in the later point off time. Apart from this, we how other services and water and all three limitations on those services. But we don't use all the services, so so we just concentrate on easy to service. Now let's go back to our AWS account to create an easy two instance. This is my ed oblivious management console where you can access you were terribly a services. As I said, we are going to deal with easy to service by clicking over here barrels. You can such from here, Let's type for easy to and you can see here, which also what's in the cloud. That is what we are looking right. This is my issue to dashboard. You can see here are this moment We don't have any running instances you can see by clicking dis option You can lunch You were forced easy to instance other ways you can go inside We were running instances and you can create your new easy to instance on One more thing you just need to observe is here. You have your reason in a jobless, we have different data centers. You can choose whatever reason you want. In my case, I'm choosing member reason toe create my yeezy. Two instances. Let's choose memories. Iam on. I'm going toe shoes. Running instances. We don't have any running instances and you can launch new instance from here as well. Let's choose this option Now we have a quick start where we have different operating systems are available. That is the beauty off your jobless. There is no restriction that you should use only specific operating system we can use. Ruben toe already had Cecily Knicks. I'm a John Our Windows systems like this. We have various options. In our case, we are going to choose Red Hat Enterprise Lennix. So let's choose this one on. Moreover, it is free to eligible. No, Here we can choose the capacity off our system. We are launching any instance for learning purpose so we may not required larger instance so we can go to the Tito Micro which is free to eligible. Apart from this, if you choose any other instance, type it oblivious is going to charge for Bert. So let it be 82 micro over here we can get one CP 11 GP ram Next choose the Conficker Instance details here Nothing to change. Only thing is number off. Instances off course we need one. Let it be then goto our stories. This is to store our operating system. We are going to choose the default options Nothing to change next to goto our tax Here we are going toe ad yet tag toe over easy to instance so that it could be easy for us to recognize So let's idea Dad on the tag name. I'm giving name. So the name off those instances I'm giving red hat but it had to settle it. You can give any name next to Goto Conficker security group And don't change in the security group. Let it be with the default, we are creating a new security group. Next review earned lunch So most of the default options we have to Jim. So let's lunch it. Why launching you should have you keep it. Keep their nothing but your password to log into your system because we are creating your server in the cloud so you don't get any credentials. So Keeper is the kind of credentials we should use. Keeper, We're lagging in tow. Our system So far we don't have any. Keep it. So let's create a new keeper By choosing this option, I'm using your keeper name as you Lennix Key. Let's don't Lord this. Keep here. I have downloaded my keep it and it is it painful? Next launch Instance. So we just launched an instance It would take miniter too. Get it ready, Goto Were instances currently over instances in training stays Let's wait for your way. I just to refresh it it on. You can see nobody's running state. So this is how we can provision year Lennox. Easy to instance, on terribly is cloud in next video we are going to see how can we connect with this system by using our keep here. Thanks for watching and see you in the next video. 5. L5 - Connect to a Linux server using Mobaxterm: Hello, friends. Welcome back in this lecture, we are going to see how can we connect toe our Lennox? Easy to instance, in our previous lecture, we helped create earlier redhead Lennix system and it is up and running. Usually if we want to connect over Lennox system from your Windows system unity a tool to connect we can use Put er, mobile Ekstrom are any other told to connect to our system? In our case, we are going to use Mobile Ekstrom as a tool to connect over Lennox system. Let's go under download more by extreme tool such for more by ex term click on the first link yourself. We have two additions in the mobile Ekstrom that is Home Edition which is free on the professional edition which is paired one. We are going with the free edition. Don't Lord No. Here again, we have two options in the free air isn't either. You can use the portable edition nothing but just a download on the run. Whenever union Adel's in salary reason where you can install anywhere window system. I'm going with the portable reason. If you are using Mac Quiz, you don't require the stool because in Mac ways we can directly connect to the server by using the terminal. No, let's open the directory. So here I help my boy Axum. Let's extract this one and going said toe this animal by Ekstrom Let's click on this. All right. I have opened my Mobil Xom. Now I can connect to my Lennox system by using Mobile Ekstrom, Let's to session on Tuesday As a church, you are going to understand What is this? A stage in the later classes? Now we should probably our remote host nothing but our Lennox system I p address Over here . Let's go back to our AWS console and grabbed I p address Here you help public I p address we how public as well as private eye piece as well. So we must go with the public, not with the prior it duda public ap address over here on Dad wants the associate settings and used to keep it. If you do remember, we have don't order the a keeper by launching our server so we should lure that Keep it. I held this keeper under my don't Lords directory so let's lower this keep it and ok took a knee. Now it is asking for user name. I'm going to give user name is easy to minus user, This is the default user name. If you want to connect to air Oblivious are Hey, chill in ecstasy to instance That's all I just locked in. Tomei are hit Shell Server. I'm going to talk about this panel in the later sessions. You can hide this one by clicking this option. This is how you can connect to your Lennox system by using more by Ekstrom No, our environment is ready to start working with our Lennox comments. So in next to section, we are going toe proceed with our Lennox comments Thanks for watching this radio on. See you did. 6. L6 - Connect to a Mac: Hello, friends. Welcome back in this lecture, I'm going to show you How can you connect to you? Well, Lennox, easy to instance, from your McQuay's. I don't help Mac system, so I'm just trying to simulate that one in window system himself. This is a get best session. It's similar to your Mac terminal. Once you log into your Mac Turnell, you just need to go inside to the directory where you kept you will keep here. So in my case, I directly we opened the git bash in the directory where my keep it exists. So just right. Click and click on. Get back here. Let's maximize it and increase the princes here I have Lennox Que Dark pimp No, to connect to our Lennox system, we need to grab Die appeared yourself over Lennox system. Let's go toe over management console and crab. So this is my red ablaze console, and you have I p over here. But you can get the commander directly from actions connect and you have your option how you can connect it with system. If you try to understand this command you were trying to connect with what system through a sausage Andi, we're loading the keeper. That is the reason I asked you guys to go and say to the directory, Were you help keep here. If you don't want to go in and say we will keep your location, you can just give the full part off this. Keep here, then. Easy. Two minutes, User art. You were public. The anus or public AP Atriss. Let's copy this command as it is and execute on our good bash session. Nothing. But it's like your turn now. So right, click on we help keep it in the same location. So we don't need to give the full pots other ways. You can give the full part off. You were keep here. Let's connect. And it is asking me whether Do you really want to connect? Yes. And you can see here I hold locked into my are Hey, chill system as it easy to minus user. Okay, this is how you can connect to you. Were Lennox system by using terminal on Mac ways are Lennox ways. That's all for this lecture in next lecture, we are going to see how can we exclude our Lennox commence? Thanks for watching and see when the next lecture 7. L7 - Linux Filesystem Hierarchy: Hello, friends. Welcome back in this lecture, we are going to say Lennox, file system hierarchy. Let's largent over Lennox system to find out what and all file systems are there and we'll compare it our window system so that we can understand. What is the use off each file system? Let's jumping. This is married her server, which is open turning. Let me take the public ap addressed to connect. This is my mobile Ekstrom console Shushan? Yes, his church I p address. I'm loading my keep here. So this is my Lennox key. I usually keep all my case in your single location and easy to minus user. Okay, so I just logged in as a easy to minus user. This is the user, and we don't have any passport. Whenever you are logging onto irritably a server you were going to use easy two main issues arise the default user on the password rather than password. We're providing. Keep it. Keep it is conduct password. We can still keep your password for our you see two minus user. But we are going to see that in later classes. Before that will see file system hierarchy on Lenox system to understand that one. I want to become your root root. Nothing but he s super user in our window system. Normal user and administrator users to kind off Users are very similar way in Lenox to users are there. So I'm switching back to yet root user Nothing but administrative user Earlier I was a C to minus user No, I became your old user for that I'm using It's you d will you su minus? You are going to understand these commands in later but we just too sick to tow our route User on da If you want to know what and all file systems are there, you just need toe execute ls slash Okay, this will Italy water null directories are created here slash Mince it easier route So there's a lot of directories are pile systems which are available among this will find out only important ones. So first barrack linen Miss slash This is a top level directory, usually in windows. It starts with Syria similar very in Lenox operating system. It starts with slash This is a parent directory for all other directories. Even in Windows C is the parent to directly for all other directness. Similar way in Lenox slashes the pair introductory for all other directories. It is called as the root adultery. We can college a slash our route directly. It is represented by slash. Okay, so we don't write it as your route. We will just keep it at the slash Whenever we say slash nothing. But it is a road You can see the slash directory If you see PWD is a present working directory. If you don't know, just ignore it. If I do see the dart dart again You Prado Peter bloody You can see here now you are under rotor director. Nothing but in windows something like you warrant See Dr Similar where you are on root directory. And if you do ls again you can see the same thing. Okay, ignore about this to commence We're going to explain in later classes. So if you see here are routed directly, we have over here next to slash route. You can see the slash route over here It is home director for root user. Nothing but super user. As I said, route is the administrative user in the Lenox operating system like administrator account on window system on it. A province working environment for fruit user. Whenever you log in as the root user, you will jump into this particular slash ruta territory. It is dedicated Lee for the road user. It's something like in Seadrill Documents and Settings Administrator, so it's equal to the administrator user next to slash home. You can see slash home. Over here you were in the slash directory under slash you How Home Directory. That's where we called it just slash home. It is home directory for other users. So usually, whenever we create any normal user that user home their trick created under slash home, it provides working environment for other users other than fruit user. As I said for root user slash route is the router directly. But for other users under the slash home directory, one more there to get created with the user name. So it's like see document settings and user name understood row. Usually whenever we create user, your user get created red, sending over here next to slash usr directly. Let me increase foreign size. So we are talking about this one at this moment by default. Softwares are installed in slash area. Saturday territory, usually in Lenox system Softwares are installed under erasure. It is equal toe. You were C program files next slash bin directory. We are talking about this directory. Slash been it contains commence user by all users. So whatever Lennox comments were executing as a user, all those comments are stored under slash being directly. Next to slash has been this is the directory. It contains commands user by only super user. There is your differentiation between the comments executor by the normal user and super user. Few commence. You cannot able to execute as a normal user. Those kind of comments you can see under its been so the root user are super users which we can create those users comments are stored under Yes, bean next to slash where this is the one slash we're nothing but variables. It contains variable data like males log files on so on. Usually this is there. We keep all over logs. So these are the important directories which we want to know. On Lenox operating system, you can see few other directories dio e t c minty Whoa pretty Brock. All disorder directories which are used by the operating system Most of the cases, but as a basically an excuse. Er, whatever directly as we just discussed, that information is sufficient. Now, if you see the Lennox file system hierarchy, you can see the same thing. It is route. I think it is not visible properly, but slash been Bhutto dio. Whatever their place, we have just seen same thing. Are there under where you can see? Can she logs? Pool temp. These directories are there under U s. Sorry. Consider beina. These libraries all decide their this order direct place which are available on line Next file. System hierarchy. That's all for this lecture. We are going to execute our commands from next video. Thanks for watching. See you there. 8. L8 - Linux Basic commands - Commands: date, cal, uptime, whoami: Hello, friends. Welcome back in this lecture we are going to see Lennox. Basic comments. You can see a lot of comments are there? We are going to eggs. Good. Each command and we'll see. What is the airport on the How can we understand the airport? Let's start me to their debt command. I'm using the same Chechen which I used in my previous lecture. Let me clear the screen. I'm executing your command called a date. And for your information, I'm your route user. You can see the debt. Tuesday, June 18th I earned it. This is the time. It is UTC time under 2020. So this gil information about your system time. This is the system time, not your local time. Usually on your debris. A systems. It is UTC time. Next to command is Cal shows this month calendar. So let's execute Cal. You can see it is June month under today date is 18th. That is the reason you can see that your estate So, Kallis Amanda, which will displace the current month calendar next up time shows current up time. Let me execute up time and you can see the output. This is The current time on your system is up and running from past 21 minutes on one user is logged in. That is me. On the average Lord, we don't have any Lord on this system. So up time is which can help you to identify how long your system is up and running in your team. All absurd. And somebody came and ask you that. Did this are Burgard Reboot her last night. If you don't know, you can just execute up them. So it will tell you that how long it is upon turning next to who am I? It will tell you that as a rich user you how logged in If you see I how logged in as root user. That is what it is saying on Lee. If I switch back to my easy to minus user nothing. But if I just give exit, I will become an easy to menace user again. If I doe, we are my this time It is going to show me as a easy to minus you again. I'm switching back. Toe root user, that is yes. Siri, worry a su minus about this command. We are going to see me later. Classes. All right. Next to think finger displace information about user finger users. I really all these comments to displace the same kind of information. Let me exude all these comments it may work Are may not work. Yes, this comment is not phoned in this system. In few operating systems it works. Then users you can see it is displaying as a easy to minus user because initially I logged in as a easy to minus user. Then I escalated as the root user. That is the reason users is giving the right information. As which user, you how connected toe this system then i d. It is going to give the current user I'm your route. So root user, each user will have you use already group ready groups All this information You can understand these in the letter classes, but it would displace the user information we have executed. Who am I right? Similarly, we have who who will tell you that as a rich user we have logged in tow river system And what is your public ap This is my public ap. If you're such for what is, maybe it will tell you. What is your Internet? I p you can see here. This is my Internet i p Same thing it is displaying over here next to W command. W command also give the similar kind of information. What is? They were used already. And from there you how locked in when you have logged in. And what is the ideal ideal time? Because we are executing comments. So there is no ideal time. How much CPU Amusing. All this information displays with the W command. So we help commands later that blew. Who Who am I? All these Gilda? Similar conduct information. Even even I d and users as well on one last comment that his man comments shows manual off command assume that you don't know what is the purpose off the commander under How does it work? Then you can use them, man, If I give the blue virtual manual pages off who shows who is logged in and water and all options, you can complain with this particular command on. Also, they will give some examples, but you can find the information about your command by using man command. All right, that's all for this lecture on to see you again in the next lecture 9. L9 - Read a File - Commands: cat, more, less, head, tail : Hello, Grace. Welcome back in this lecture, we are going to see how can we view your file? Usually in windows, we can just double click toe open your files. But in Lennox, we held different comments. Depends upon how do you want to read? You can execute this. Commence pasta. Let's pray with a less command. So I'm on my server and I have logged in as root User, if I do a less over here, you can see there are two files. A less turns for lister. It is going to list or the files are directories water there. In the current working directory, usually in windows. We just go inside to the directory. If you go inside to the directory, you can able to see all the files under directories. But here it is not the case. Once you go inside to your directory, you need totally start files By using a less command on. I would like to introduce one more command. That is Peter Bloody. Build a blue. This transfer president working directory, which will tell you that on which directly you are you can see here I'm under root directory. This is my present working directory in Windows. It is something like this. This is your current working directory. It you are under my PC desktop Valek See? And they don't lords in this. You have these directories you can see the directorate's over here. But in Lennox you need to exude a less commander to see the content off. You were directly under. Even if you want to know the in which party were working, you need to exude the PW recommend. But here you can declared and credit. Okay. You you are under desktop. Relax, It downloads and you can see these files. That is how it works. Next cat filing usually to view your file, we can use the cat command Here we have two files right on corn RKS Dark CFT original case , Dark CFT Just I'm tryingto open. Ignore about the content Water What it has can't followed by the filing. If you go this one it is going toe display the file name but it is very big fell. So we are at the last place off our file. Let's go up. So it started here. We're started here. We have just or displayed the cat command on da This is where it started on lot off information is there? I'm just a scrolling down Whenever you execute cat command, it would displace the file, but it directly go to the end after file. You can see the last page off your file. Next list. I'm clearing the screen in Lenox to clear the screen. We are executing your command called really? Yet again if I do. Unless this time I'm executing less So less command is going toe Display the file page by page. You can see here This is the starting off your file. Right on, da It is the reading, this file And this is the first place under. If you enter the space, it will go to the next place. I'm just entering space. It is Next page next page next page like this You can oneto the different pages by using this one until you reach to the end After file Now you reach to the end after failed. If you want to exit and quit from this well, you just need to give that you so you nothing but create I just given to under I came out so less is installed for displaying inter file. You can read file page by page next. More, More also works similar here. Okay, you can see here. I'm reading faster page of my file it is 15% is off our file. Next. Next, Next, next, Here. Also, we need to give space Onda, we reached end up the file. So this is how we can open our file by using less are more next to think hairdo If you would like to know only what is content is available you don't want to read and there fell . In that case, you can use head our tail command so head will displace the foster 10 lengths off work file So I'm giving the same file head on. Differ display. If you come to these files, you will find 10 lines. Ok? Faster 10 lane self. Your pile is going to displace the head to command similar way. We hope they'll command Dale is going toe display last to 10 lanes off fever pile. Okay, tell I'm giving quite slim and you can see here this is and this is the end of fever file. Okay, so it used the last 10 lens and head will do that faster. 10 lanes. I assume that you need faster, pointy lines. In that case, let me clear the screen. I can give head 20 on my file name. So Saudi. I heard the minus 20. So head to minus 25. Let me figure it is going toe. Displace that 20 lane self ever filed. Similar where you can go pail minus 20. Let me clear the screen. Tail minus 20. File name You can see last a 20 lengths off your file, Master. 20 lengths off. Ever filed. This is how we can use head or tail commands next to Paige. There's also similar toe Lesser more command. It is also going to display the same command again. It doesn't work on some operating systems, so here it is, not working. So these are the comments we used to open are really a file. Thanks for watching. See you in the next video. 10. L10 - Creating files - Commands: touch, cat, vi: Hello, friends. Welcome back in this lecture, we are going to see how can we create our delete files or directories before executing these comments? I just would like to say Don't get scared by looking at these many comments because don't think these has a different comments, which you need to remember because for same purpose, we have multiple commands so we can use anyone off them. Depends upon the next city. And, ah, once you habits related to execute this comments, you don't feel like these are comments. You just think that diesel are English words. Okay, now let's start. How can we create files? Bust Foster command is touch created Jiro Birds phone, usually in windows. We have different kind of files like word, file, text file, excel like this. We have different kind of files, but in Lenox there is no such kind of extinctions. Everything is a flat file. Now we'll try to create a file by using touch Command. This is my Lennox system. Currently, I'm under my root directory under route. I have to fells now. I'm going to execute a commander called the touch, followed by filing him. I'm giving file one Dr 60. Okay, this extension can be anything Even we thought the extinction Also we can create a file now let's created. And if I do again, unless you can see now there are three Fells. Initially, it was only to know one more file. God creator. Now it's time to learn little more about a less command in Lenox. With the comments, we can also provide flags, flags Nothing. But it will give some additional future. For you were existing command. Let's take a less comment. We can add one more flag called Il Yell stands for long list. This ls terms for least this yells transfer long list. But whenever you are using flags, you need to specify a minus in front off ever flag nothing but ls minus. Yale are hyping. We can call. So ls hyphen l If I exhibited this one, you can see same files. Information has been displayed with a little more detail. That's why we called as a long list. Under there are some information in front off this one for time being. Just ignore it. We are going to know about this one in the later sessions. If you see here you can see it. Three files are there. I just would like to highlight this one. You can see here. This is the size off your file. Whenever you create any file by using touch command, it is going to create with the Jiro bites, it means that it doesn't occupy any space. That is the future of touch comment on also, if you see your ls minus hell command, it is going toe display. You were filed in the alphabetic order. If you see a new condo file is the starting character, then file one year is the next character, then original. What is the next character? So it gives in the alphabetic are dirt. Now we are going to add a few more flags to the Ellis. That is, unless minor cell next minus t OK minus two stars four times. Time means don't display in the alphabetic order displayed depends upon the time. When was the recent fell God Creator in this case, this file God created recently on June 18th on? These two fellas got created at the same time on April 23rd. So if I display with ls minus l, you will get long list with the time stamp. So this file will come as your post one. Among these two, both are in same them. So it may come a new condo as your 1st 1 then original as the 2nd 1 you can see here. This is how it comes on. We can add one more flag toe, the same commanded That is our r stands for reverse. So reverse nothing. But whatever you are going to display with the ls minus. Lt just reverse this secret. So now you are going to get orginal as the fast lane. Unorganized. That second line file, is it, darling? So this is how we can execute now. If you see, we are using three flags for each flag we are using minus rather than that one we can use ls minus yell tear. Nothing. But we are combining all these flags with the single manners. This is also valued command under to displace the same output. What we have seen in the able command. This is how we can use flags on most of the comments. How flags Few commands doesn't help flags like a Peter bloody doesn't help any plans. Okay, so this is about a less command. Now let's go back and see what and all other options are there to create your file. Next to command this cat filing create file on Arlotto, right? If you do remember, we have usually account commander toe, open your pile. Right. But at that time, we haven't used this greater than symbol. Whenever you use greater than symbol, it is going to create a file on it. All those you too. Right? Okay, now let's go back on. Clear the screen. Yes. Ls minus clt are and one more information about a less meniscal tear command. Usually in your directory, you may have 100 south piles. Now, you would like to know which files got recently updated then this command will be helpful because it to displace all 100 files in the sequence under whatever was latest update. Er, those will come at the end rate that that's how you can. I didn't play which pills were recently updated out. Recently created. Usually we commonly used this command in the real world. Now I'm using cat greater than file toe. I'm giving file toe Now. If I try to give without greater than what does it do it to try toe open the file? But there is no file Carlo file to right. That's the reason it is throwing an error on DA in. The Ararat is saying that while do no such Baylor directory again, I'm giving slash. Great of them Space filed toe. Now you can see here. Carson is waiting toe. Take some input. If you give some input, it is going to write that the data inside ever filed toe. Okay, so I'm writing the seas fighting toe created with cat command. Okay. On the Endor at the end of the lane, you need to give control, See, to come out on giving control. See? So you can see here this carrot see nothing but control. See, So I have given controls is so it created here file that is file toe. Andi, I have given a less menace shell. So it is going to give in the alphabetic order file one under file to both our file on one toe. So one is having highest priority competitively toe. Anyway, now, if I open this file, I can still open with the cat command more less head to tail. All these comments are helpful for me to open this well, but we are going to use cat command because it is two lanes. Okay, if it is bigger Phelps, we may go with less or more page all these comments. All right, So this is how we can create a file by using your cat command next one nano. Okay. Other were to create a file is like using editors here. We have a couple off editors in Lenox. So if you want to edit any existing files are if you want to create a new fail, we are going to use editors. So Nano is the one off the editor which we can use. I'm going to give filed three over here. Okay. Anyway, Nano is not installed. How to install Nano. We are going to see in later sessions. But now now is the one more option to create a file on one more option we held. That is V A V, a editor. We called okay anywhere. File three is not created. I'm going to use file three were over here to create with the levee. Eight. Andrea is bit complicated because you should How that some sharp cuts how to use via But I'm familiar riveted of yea editor. So I'm quickly going to write it. Hello. This is filed three creating with the editor. Once you have returned your content, you can just need to give the escape colon W Q ender. Okay. Diesel R v A comments. I'm attaching the V a comment. Shoot. So this lecture, you can download it on. You can practice it. If it is not familiar for you, then you can use the Nano command. Now, let me open this file again. I can open this file by using the cat command. Arles. I can still open this one by using the V editor. We a file three. If I do this time file is already existent. Some content is there, so you can see that content and you can hear it. Okay, you can edit. You were file content by using the V A. But you cannot. Idiot. You were content by using the cat command. Please. Remember that one. All right. That sound for this lecture in next lecture we are going to see how can we delete are headed our files. Thanks for watching. See you there 11. L11 - Edit or Append Content to a File - Commands: cat, vi, nano: Hello, friends. Welcome back In previous lecture we have seen how can we create files in this lecture? I'm going to show you How can we create your pile with Ananias? Well, I'm going to install Nano. You know what system Then we'll try toe edit file under. Remove your file. I am on my Lennox system and this is the station where I was using in my previous video. Let me clear the screen and I'm going to use nano toe Use Nano. We must install Nano. Unique is we are going to use Yum install to install any packages under Nano on the minus way way stands for years to install. Don't worry, We are going to see these comments when we go to the topic called installation For now, I just want to give you a demonstration with the Nano. For that I mean starting Nano on. Make sure that whenever you are installing this software you must be a root user Other ways You cannot install any software's even in your windows system. Also you cannot install software if you are not your administrative user, right? Something happens over here as well. So let me execute it. All right? I have successfully installed Nano. Let me clear the screen. It is also similar. Toby, Editor, I'm giving nano file for but comparatively via entered. This is easy way because it is something like you are not bad. I'm just writing. Hello. This is filed for creating with No no editor one. See how it anywhere date our here and you can see the options. Okay, right out. Nothing better to save this content then. Whereas to such for Carter text like this We have different options, but mostly we use the right out command This option you can see carrot. Whoa, carrot. Nothing but control. We should give. So I'm giving control war. You can see here File name to write. I'm writing this country and under file Poor. Yes, I would like to write it just to give enter. Once you have given enter this content get sailed. But you are still in the Nano editor to exit from the Nano editor. You have your option, Carrot X. Nothing but control. X So control x I'm giving. So I came out from my editor on dime giving a less minus. L again You can see one more file God created. And if I open this file, you can see the content. If it is less content, usually we go with the cat command. If file is big and so many places are there, then we go with the more or less commands. Okay, so this is how we can create files using Nano V a cat on the touch. Okay. For your information, we have created a file using touch, but you want to write some content inside the touch. In that case, you can use the cat command cap greater than file one. Okay, this is how you can write some content inside your file. But the problem here with the cat command is if some data is there in this file one, then it is going toe war. Read their data. So this cat great than command is something like we are war berating existing file data. Okay, so let's see, as off. No file one is empty fell because we helped created a veto that touch command. And it is Jiro Birds. So no, I'm giving Hello. This is filed one created with touch added content with cat. Come in. Okay, so This is how you can write content using cat command. Now, if I open again without greater than again, it is like opening your mail so you figure greater than nothing but writing inside the file . If you're if you don't give any greater than it means that you are just opening your file so you can see the content. Now again. If I try to exude this command, what will happen? It is going toe war overrate the existing data under traits. Other data. A gym that I'm just giving. Hello. This is File One and I'm not writing anything under two exit control Syria it. And if you do control, see you over here at the end after existing lane it don't recognize this land. Please notice that anyway. Now, let me see the content off the file One you can see previous content Guard cleared on. I just added again this Tulane's under. You can see this Tulane's Okay, So that is the problem with the cat greater than command. Then what is the safest way to adfl? That is where V A under Nana comes into the picture. Okay, so I can edit my content by using V A file. Okay, you can see your file has been opened on the content. Is there on DA If I do well, just a war. It is going toe inside. Ian Newland, this is this is created with touch command. Okay, I'm just to saving this failed escape. Colon blue que to save the file. So cat file one. Okay, now you can see three lanes are there. This is how you can add it on one more. Where is to edit is again nano. So nano pile one and ah, I'm coming down And I'm saying that a return Evita Nano under to sell control war Enter control X. That's it again. Clear the screen card file one. If I do, you can see the content What we held it on. So this is how we can edit our files by using Cap Commander v A under Nana. And in cat, we have one more command. That is cat double greater than file one. Okay, sorry. File one. So this is another option where you can add the content to tow the existing fell Nothing. But if you use just a single greater than it is going toe Overrated work content. But whereas if you use double greater than it doesn't touch the existing data no. Whatever data you are adding, that will be a pender toe the end off this pile how we have upended, evicted the V A and the Nano or it same thing it is going to do on giving us there. Adding lane using cat. Okay, I cannot give controls you over here. Effect, Gil Control. See, this link is not going to recognize, so enter control. See? Now again, If I do that file one, you can see I can ableto add the content by using cat command. You just can add the data toe the existing failed You cannot aided the data. Assume that instead of file one I want to make it as a file toe. Then you must go with the V a r Nano. So I'm going with the Nano file one Onda Jim that I want to change it to the pile One toe file toe Just I can you file toe just I want to remove the send airline. I can remove it. Okay, So all this stuff you can do, but these options are not there in the cat command in the cat command either you can. Sorry I'm using so control war. Enter Contra Alex. So in the cat command, you just tow overrate the existing data barrels. You can append the new lands to the existing fell. Those two activities you can do. So this is how you can edit liver pills. Thanks for watching in next video, we are going to see how can we create a directories? 12. L12- Create Directories - Commands: mkdir: Ha LaFrance. Welcome back. In previous lecture we have seen how can we add content are added content in your file? In this lecture, we are going to see how can we create a directories? We haven't to discuss the board the, um, command yet we are going to see this one anyway. First will go on to create a directory to create a directory. We are going to use the command, Carly. Um, Katie. A year. So directly. Nothing but your folder in Windows operating system. Usually we create forwards, right? Similar. Will we create a directories? Let's go on to create your directory. So I'm in my root user on my current working directories slash route on the list. We hold these files under this location. Now I'm going to create a directory to create your directly. We are going to use the command called, um care D a r. Under directory name. I'm giving d a. R one. So we just to created your directory? No. And if I do a less again, you can see this is the directory. It is in different color for identification, but in some operating systems, you cannot see this color difference you can see like your files. If that is the case, it is difficult to identify the which is directory and witches file because we cannot give the all the directory names as your d a r straight. So that is the reason we can use a less minutes l command, which will help us toe. I didn't way which is file and which is directly. And if you see in this command you have u minus over here as well as be so by looking at the faster character in your ls minus l command you can. I don't weigh whether it is a file or directory. If it is minus Minh City's a file, you can see here for all felt it is minus. Whereas if you see as a D means it is a directory for this one, it is their directory. That's how you can. I didn't fake. All right, so now we created their directory. Can I write in your directory? Off course Not right in windows. We create folders within the folder. We can keep other files or directories. We cannot write on your directory, right, so something will happen within the directory I can keep My files are I can keep my directories within the directory for how again? They're a tourist. Then we called as a subdirectories, like in windows. Also within the polar sea. Free health holders We called as a sub folders. Write something over here instead of folders. It is this subject, please. Right. So I can go in, say, toe this directory and create files are directories again. But anyway, this is how we can create a directory. This is a new directory, so we don't have any content inside that directory. Know how can I go in Syria directory so you can move on to your directory by using thus Siri command So, Siri, nothing but change Directory change directory. So, Siri, followed by your director Enemy figure. You are goingto change your directory before changing my directly. Let me check in which directly I am. You can see here you are under slash rotor directory. Now let me switch to the D A. R one. So Serie de Air one. And if you see your present working directory, you are slash roots last er one. If I goto my windows. If I create a folder I can just create a new folder. Once I helped created a new folder, I can just a DoubleClick DoubleClick. Nothing, but I'm going inside their directory in Lenox. Double click is not possible. That's where you need to use that. Siri Command, this is fresh directory. So no content is there on my directory structure has been changed over here. Same thing happened here as well. All right, this is how we can create a directories online, explore pump, and you can create multiple Berkeley's by using em. Cure the air command that is incurred air. They are two day or three d airport. So, like this, you can do even in our previous lectures. Also, touch command can create multiple files. So now what I'm doing, I'm creating subdirectories within the D a r one you can see here. This is my present. Working directly within the directory. One I'm creating subdirectories. Let me create. And if I do? Unless you can see here three more directly start. They're off course. These also empty directories. Now let's go back and clear the screen. Unless I just came back here. You cannot see because I need to go inside to the D A r one there only can see the other directories. So, Peter bloody I'm under route. So this is how you can create a directories. That's all for this lecture in next lecture. We are going to see how can we delete files or directories? Thanks for watching. See you there. 13. L13 - Remove FIles and Directories - Commands: rm, rmdir: Hello, friends. Welcome back. In previous lecture we have seen how can we create a direct please in this lecture, we are going to see how can we remove files under directories? So to remove your file, we are going to use the command called arm arm Nothing but removed. Let's go on to remove your file. This is my Lennox system where I help your directory and I help file says Well, before executing other commands, I'm going to show you one more Commander, that is Treat okay. Three is the simple command which will tell you what is your direct researcher. By default, it may not be available. If it is not available, we can install this comment. Okay. It is not available. I'm installing it. How we have installed over Nano Yum. Install three minus. Wait. Okay, I have installed. Clear the screen. Your list deserve the file. Straight on. If I get three, you can see here. So this is the file. Under these all our files on we have directly one within the directory. One we have directory. 234 Okay, you can see here this symbol. So tree is the one off the easiest command, which will tell you how the directory structure has been created. Now, I would like to delete a file. I can delete my file by using a command called Autumn. Okay, Autumn followed by filing. So if I execute this one, do you want to remove this file? Yes. Off course I want to remove it. I can give. Why? Nothing but yes. And if I do a less now, you cannot see the file one again. I can eggs go to just quickly. There is no file one. So by using arm command, we can remove your file. I can still remove multiple files by using Adam Command file, file file three, file door and fell. Three like this. You can do any number of wells. Yes, I want to remove. Yes, I want to. So it is asking us to confirmation to remove file or not? If you don't want to get your confirmation, we have your flag called the year. You have stands for fourth so you can remove your file forcefully. If I check tree again, you can see only you have the air one on file for on the remaining two default pills. Okay, now I want to remove the file. Poor Andi. It should not ask for the confirmation. Then I can use the RM minus. Yep yep. Stands for force on file for now. You can see here. It didn't ask me that. Do you really want to delete this file or not? And if I do again three. You can see only you have directly stretchered which you how Creator. All right, So by using our, um, command, we can remove our files Now, I would like to delete my directory as well. Okay, so let's go under dilate our directory. Soto Duality. A directory. We are going to use the armed the air Command How we use young k d a r e m k d a r Nothing but make a directly similar Were rmd air removed Directory So I'm giving RM d a are far or by my directly We'll see what output we are going to get with this command on. But it won't mind if you have more space is okay, but in Lenox it is case since two. You should not give the Cap City okay, so you can see here what it is saying Artem dear, failed to remove the air one directly is not empty. It is saying that I'm trying to remove this directly. But this directory contains some files or directories. So arm the air command will work only under directly which is empty. Nothing. But if I check inside this directly should be empty. Otherwise it cannot able to delete. So I cannot believe to the air one before deleting. They are one I need to daily to these directories. Right then only I can remove. So in that case, what I can do I can goto the air One Togo inside Syria, the air one under a tree. If I do, you have three directories are even less menace. L also you can. These three are empty directories Now. I can't remove these directors by using armed er comment. So armed the air D a r So they are three b a r four. Okay, like this I can remove, but I don't want to make this ender directory empty This way. I'm removing only d a r toe just to show you that if directory is empty, we can able to remove that directory so you can see here on the ls. If I do, I help him or the d a r to Aria. Less minutes. Elikann say they are to a hell removed. Now we have the air 300 year for all right. So here we are using a less minus l instructor less minus l you just use a little command. Both will give the same old put a little. Also similar to the ls minus. L command. All right. Now it is only three directors I can remove these lyrically is and go back under day Lida the air one. But if you have hundreds off files under directories, how can you remove these files or directories? That is where we have one more command. Okay. Under? Yeah. By the way, Syria. Dark, dark, nothing. But you will come out from your directory. So earlier I was inside my d a r one right now. I came out from the d a r one. So Siri Darthard, nothing but go to the pair into directory. Goto the apparent a directly I think I have exhibited this command in previous lecture. It's also I've missed her to explain it. Anyway, we are going to see that one in later. So if I check my PWD, I'm under route. If I do a less now, you can see here you have the air one under three. If I do, you can see within the the air when we still have two more directories. So I cannot takes good rmd air the air one because it is still not empty. If that is the case, we can use the command are, um minus. Yeah. Okay, If you do remember, we user this command to remove over piles. Okay, Same command we can use to remove directories also, but we need to add one more flag that is minus R r stands for records. You So I'm saying that record actually delete all the content of it in the directly r stands for records. You you f stands for forcefully, forcefully removed. Either it is the filer directory removed. Enter director Stretcher. If I give the air one, it is going to delete it. Ok, But as I said earlier, instead of using different flags, we can combine these two that is are a menace. Are if we can do so. Eggs Aguta Adam minus rfd air one. Now, if you see here, there is no directory and it is clean. Whatever files are direct. Chris, we have created everything we have remote. Okay, so this is how we can use the atom command. One last useful command which I'm going to show you on also dangerous, that is, are a menace. Art of star. So this is very dangerous. Command, whenever we were executing are in command. Please be cautious. There is no recycle bin in Lenox. If you are diluting something, it's deleted. There is no way to recover that. While that's where backup is the most important are necessary stopping the next environment in windows. If you're deluged something you can go into retreat, at least. Probably sickle being here. There is no such kind of option, so be cautious. Well, executing Artem command especially, are a menace. Heart of star. Okay, so start is the wildcard character, which means equal toe any file or any directory. If you want to delete, enter structure our entire folder. If you want to delete 100 files are directly on Subdirectories are there? We want to dilute enter stuff Then you can use the, um minus sort of command. But please, cause yes. Well, executing this command, we may use disc amending the latter station part. No, we are not executing because I'm cautious on. I don't have any files to delete at this moment, so I'm stopping over here. That's all for this video against you in the next video. 14. L14 - Copy Files or Directories - Commands: cp: Hello, Prince. Welcome back. In previous section we have seen how can we create our delete our files or directories in this section? We are going to see how can we manage our files or directories? Let's starts with the CPI command, CP. Nothing but copying your file. So I'm on my Lennox system. I don't have any files. At this moment on this system. I'm going to create a new file that is touch file one and file toe on. Both are empty files way because we have created with their touch common. Let me are some content in file one. I'm going to use the cat. Great with them. File one. There is no content I can use greater than without any issues. Okay, this is the content I'm adding. Hello. This is filed one adding content of using cat command on. I'm giving enter control. See now if I open file one, you can see some content is there at the same time. If I open file toe still, it doesn't help any condemned. Now, I would like to copy content, Whatever is there in the pile. One on to file toe. If that is the case, we can use the CPI command CP File one Space file one space filed toe. Okay. CPI command works like this. This is the source. Well, nothing. But where the content is available On where do you want to copy this one? We called as a destination felt so source file to destination fell. We are copying our data, so let me execute it on. But it is asking. Do you really want to overrate file toe off course? Nothing is there. I don't have any shoe toe overrate Onda, clear the screen. And unless again, unless Manus celibacy are earlier It was Jiro Birds. Now both house same content. It is using 49 bites on DA. If I open the file, one are all spoiled toe. Both are having the same content. This is how we can copy our content from one well to another file. Now we are going to create your directory. I'm creating gear directly colder. The air one. So here. What I want to do is I want to copy this file one until they are one. Directly. Nothing but waiting. This new directory, if that is the case we can use against CP command. So file one and they are one our earlier. We have given CP file one and filed toe. If you are destination location is a file, then it just to copy the content onto the that particular pile. It doesn't do anything. But if your destination location is their directory, then your checks for whether the file one is already exist over there are not, if it is not existed is going to create yet File one, copy the data. It's something like this. You want to copy a file on windows from one location to another location, so you just do the right click Copy. Andi will go to their destination and placed it whenever you pressed it. It creates the new file, right? Same thing is going toe happen over here, So let's see. No, if I don't three. No, you can clearly understand. So we have your file one over here on there is one more file God created under. They are one because we have used the file one followed by the directory. Whenever we specified directory within the dark, late career stuff, I'll Okay, so it copied the file one. And if I want toe. Read this data. Either I can go inside to their directory and open this well, articles I can just to do the cat dear one is the directly right slash file one. Okay, here slash Nothing. But we are differentiating. We cannot give. They are one file one. We must do the slash file one. Okay. This is how we can weapon Let me open. You can see same content has been copied into the d a r one slash pile one on. Also we can use copy under directory says, Well, let's see less. Now you have directory one. I want to copy the sender directly onto your new directory. Then you can use CPI the air one under the area to nothing but whatever the air one content is the same thing. I want o un g a r to now. In this case, both are directories, right? So there is a problem. It'll the CPI command, if you use CPI commanded, cannot able to copy the directories. It just to copy the only friends. But do you have flags? Right? That's what I was saying. If you use flags, it will do additional futures here We can use minus R. This R can be either uppercase Our lawyer kiss either will work. R stands for trick. Actually, whenever we use directories, we must use the our command. Let's eggs. Good on. Defy dutifully. Now you can see there are two directories D a r. 100 year to whatever content is there in the day are one same content copied onto the dear to this is how we can copy directory says Well, so now we have seen how to copy a content from one point to another file also, how to copy the files onto your directory on how can we copy directly toe another directly on you cannot copy director into your felt right. It doesn't able to hold it. Okay, so that's all aboard the copy comment. Thanks for watching and see you in the next video. 15. L15 - Move or Rename a File - Commands: mv: Hello, friends. Welcome back in this lecture, we are going to see how you envy Commander does work. Um, via stance for moving your fail. If you want to copy your file from one location to another location, we are going to use young be commander. It is something like Captain Pasting Willows. Okay, this is my Lennox system. I helped to direct risk on the each directly we help I'll 100.2 now. What I want to do is I want toe move this pile toe onto their directory toe. I want to move this file toe onto the directly toe. Then I can use this command. This is Sam's index like over CP itself. Young v source file. Which file do you want to move under D A r two. So we are giving directory as the destination so it will go inside. Go there directly. Whenever you move, it will go inside to their directory. Now, if I give you three, you can see earlier the file was outside off this directory. I mean to say under my home directory. Now it is more toe that they are toe nothing. But you can see over here. This is how you can move your felt on Also quite commonly in introduce. People will ask that How can you rename your file in Lenox? GMV Command is user to rename your pile as well. I assume that I want to rename this file. Want to file three? How can I do that one so I can go inside. So they are too. Only unless if I do, I helped file 100 file to read. I just went inside to this directly. Now I want to rename this one toe the pile tree. What? I can go young, be filed. One profile three. Okay, Whenever we do you envy Whatever content is there in this file is more than toe this. Well on this file, getter disappears. This file get disappears, right? So that is what actually happens. So now you can see you have only file during the final Three. It means that we have only filed three because we copied this data into the File three and file one guard to disappeared. But logically, if you see we just renamed Outlier. There was a pile one. Now it became your pilot tree. It means that we just rename the file. This is how we can bring him our file by using young. We command. All right, that's all for this lecture and see you in the next video. 16. L16 - Changing Directories - Commands: cd: Hello, Prince. Welcome back in this lecture. We are going to see Siri Command. We haven't to discuss liable to find on the grip. Commands will see these later. So let's go on the Understand Siri Command. Currently I'm under root directory. Okay, now I would like to go toe the parent directory. Uproot. So apparently directory off road is slash nothing. But this is the ultimate directory in Lenox operating system. How it is this year driving windows. Once you reach out to the sea drive, you cannot go a boat with Cidre, Right? Same thing happens over here. Now I want to go to the US last directory to go to the slash directly. We have two ways. That is I can use Siri Dart Dart. Usually Syria dot dot is user to goto the pair into directory Goto the pair introductory off the current directory. So currently, directory is my route from route. I will go to the apparent to directly now if I do again, Peter Beauty, you can see slash nothing, but you are under root directory. You can see the entire your Lennox file system hierarchy over here. So diesel arda starting directories are pile systems are anywhere. Lennox operating system. I was talking about Adam Command, right arm minus heart of start. If you do over here, it is going to remove. And Terry were directories, If you remove entered a reckless What is there to run, right? You need to reinstall. You were in their system. That's why I said it is very dangerous command. Whenever we were your route, you should be cautious about that anyway. No, this is my directory structure. If your eggs ableto three. Okay, it would be very lengthy output, but just I will show you how many directories and files are there with anywhere. Lennox, flat form. Okay. These other files let me clear the screen again. I'm giving Ellis. So far, I'm working only on broader directory. Now, I would like to work on one more direct recalled TMP. So this is our TMP directly. Okay. The MP stands for Tim in this letter to you can keep your temporary files. Okay. I want to go inside to their temper directly. In that case, you can do the Serie TMP. If you are giving directly name Dr Directory name should exist over here. Okay, I cannot do d a r one here, right? Because D a R one is available under root directory. So I should go to that rotor directed, then search for the air one. If that is the case, I should give a root slash d a r one under router directorate. There is a D a r one directory. Okay, now, temp, we can go directly because in this current location Sorry. In this current location we helped him. Okay, Now if I do unless there is a temporary friend. Anyway, this is how you can go to the temple. And if I do pwd No, you can see here you are under 30 MPA territory. Now I want to move back to the day or one which is there under rule. If that is the case, what I can do, I can go back to one directory then. Unless on the period of beauty here again, I have root Roto directory. Siri route on the puter beauty. I'm under route. No. Unless if I do, they are one. Is their Serie D a r one. Peter beauty. I'm under my dear one. This is how I can sift from one directly to another directory initially was under TMP Now a more toe the slash route the air one again. If I want to go back to the TMP again, I need to go back to the d a r 12 slash root slash through Toto again route Then I need to go to the TMP rather than that when we can use the directly Siri slash TMP So what does it mean? That don't consider my current working directory wherever I am just too search for this particular directory from the starting point Starting point Nothing but this is route rate Nothing but here. Okay. In this location there is a direct recall. The TMP is there. Go inside toe that temp directory That is the meaning off this one. So if I exhibit this one directly will go back to the TMP I don't want to do Syria. Dar Dar's are Siri directories again. If I want to switch back to the slash route to the air one, I can give a similar way. City under root directory. There is a directory called route Yes, off course. We have your router directory under routed directly. We have your direct recalled to the air One again Going said toe that one. This time you can see how simple it is. Okay, This is how you can switch to the you or Derek, please. Now, if you are starting you were part from the slash Then this part we called as a absolute part So absolute part Nothing. But you are starting. You were part nothing. But wherever you want to go, you are giving with slash If you give your part We thought to slash then that we call desert 11 2 parts. So let's take an example that again you are under TMP Okay? Sorry a serious last year. So now you are under TMP now again You want to go back to the slash route I have another worried that is first I will go out from the TMP so I will go back to the slash directory under slash territory. We have root under routed directly. We have day are wondering So you feel See, hear, hear The party is not starting with the slash It is starting with the dart dart barrels just hear directly as well. This week all does a 11 toe part So that is how Siri Command will work. We can switch our de reckless by using the Siri Command. If you want to go back to only one pair into directly, then we just use the Syria dot dot com. And that's how it works. And if I see Peter Beauty again, I'm under hood. That's all for this video. Thanks for watching. See you in the next video. 17. L17 - Search a File - Commnds: find, diff and file : Hello, friends. Welcome back in this lecture we are going to see find under the comments. First we'll see about the find command. Find command is user toe. Find the files are directory spot. It is exactly like find option in the windows where you can search for your file. So it is similar to such option in windows. But we are using command over here. You can see here the syntax after find command is something like this. Find slash minus option on filing this option can be any off these so minus name. If you do it, will such for that particular file were exactly Does it located? If I give minus user for files whose Warner is a particular user, if I give user called route all the files which are warned by the route it is going to display next to group for files, belongs to that particular group. If I specify the group, it is going to display the group's information. But usually we are going to use the name option. Let me execute with the name option. So this is my Lennox system. Currently, I'm under Rotor directory on Dhere. I have your file one. Let me search for the file One in the entire system. Onda will say we're in reality is located. Find slash minus name and file one. Okay, I'm giving file one and you can see here. File one is located under slash roots. Last file one on also slash root slash D a r one on file one. Now to test it. What I will do. I'm going to copy this File one unwto our TMP location, so cp file one slash TMP. I'm giving full. But this is absolute portrait slash TMP. So now if I see find same If I exude this time, it should give the part off the MPs. Well, you can see here slash TMP years old. This is how find command will work next. Let's either def command so difficult. Manned is quite simple. It will show you the difference between two files. Let's take an example. I'm just giving three. I just want to compare the content off file to and filed three. In that case, I can go insert a day or two under your less diff piloto file three. You can see here. There is no difference. I hope both will have the same content. Let me open the file on the final three. Both are having the same later. Let me aided the content off this well and will compare once again we a file toe. I'm just naming this one as it and I'm using vi editor because we cannot edit your file with the cat command. Similar were I can use Nan also I'm using Nano filed three here. I'm going toe Replace this one with the final treat. This time both files are not same. Control, war, Enter Control X. Okay, now both files are differ. If I see the content off file to on file three, I can open both the file civet of the single command. You can see this is filed to contend and this is filed three content. Okay, Now we'll use the diff command diff filed toe on file tree. So it is going to display that second line in the first file on the second line in those second file. So this is what it is there in the wild one. Sorry. Filed you under. This is what they're in the file. So it is saying that these two having the conflicts in this file. That is how deaf command will be used. Next thing, file command file command will be used to find out what kind of qualities. Let me go back to my roots. Pwd, I'm under root. Ellis, If I give file on file one, it is a file only. Right? So ask you text nothing. But it is a normal condemned. If I give the same thing on file, they are too. You can see here it is saying that this is your directly similar way. We have different kind of files. You can check those files under Devi The even nothing better device I'm going there on if I do ls minus l you can see the starting character of this one is see is there be is there and also yell is there? This is how it is. So you figure you fine. This particular phailin Jiro figure it will tell you character special fell and similar way Forgive file on this one. You can see this is a block special file. That is how different files are there. And if I do file under linker file Okay which starts with the elemental in Krefeld. Right? So if I do a study out, you can see here symbolically in two sons. That this is a link with that is hope. File command will be useful. All right, that's all for this lecture in next lecture, we're going to see grip. 18. L18 - Search for a Word in a File - Commands: grep: Hello, friends. Welcome back in this lecture, we are going to talk about the grip. Command grips transfer global regular expression Print. It is used to pick or the required expression from the file under printed output. It is quite simple. In your file, you just want to know whether a particular word or particular pattern is available or not. If that is the case, we can check out with the grip Command. So the commands in Texas, something like this grip Patron under file him. Let's go on executing this command. So I'm under root directory. I have few files over here on DA. Let me take file one If any content is there. Sorry. File one. So it has some content. I just want to grip that weather. Hello. World is there are not in this. Well, then I can use grip. Hello on file them. If that word is there, it is going to display the entire line. It is going to display the and Ireland. Yes, It found the hello world. If it is find in multiple locations, then it is going to display their all the lens wherever it finds the hello to see the more relevant example for this grip. I'm going to use their one off the operating system file. We have your file called carts. Classy. D C. Yes, It's Hitch. It's his hitch. D underscored conflict. Okay, so this is the file you can see here. I'm using with cat on. I'm giving the full part. Nothing but absolute. But under route to directly there is E E T C directory. Under UTC. There is a situation territory under associates. The region s a C H D. Underscored conflict file is there? I can use cat only under file. If this is directly I cannot use cat. I should use their serie. Okay, So if you open this one, this is a bigger file. I will directly go to the end of the file. You can see here, and I need to scroll up. Okay, So this is where we have started, right? Rather than this one. I'm going to use more command. You can see here. This is the first place. And also I'm going to such for this one permit root login. Yes. So what does it mean? That if I want to like into this system as a route user? Yes, I can log in as root user if I used this one No. Then you are not permitted to like in as a root user. So rather than searching like this, what I can do I can just grip permit on slash CDCs a shit associated e underscored conflict . Well, now you can see here in this particular file with the permit there are multiple lines Are there on among this? This is what I'm looking. No permit route like in Yes Okay, it is there. It means that I can like it as a road user because by using grip, I can able to find it out other ways. If it is a bigger file, I need to search for this particular option where exactly it is there whether it is enabled are not now. It is quite simple, right? I can identify whether it is enabled. But the problem with this one is you can see the same patrons wherever it find it is going to display here. Permit is here. So it is displaying here on Dhere Permit is here as well. It is displaying here apartment here like this. It is going to display, but same pattern. If I tried Tokyo grip you. If you observe, I have given caps p over here because it is a kiss since two you must do the as it is now you figure you pardon me to be to the lawyer case and if I search for this one, you can see here nor put which means that with the lawyer case permitted, there is no any keyword in this particular file. But this p either it is. Caps are small. I don't know if that is the case. We can use grip minus a option. As I said it. Whenever we use flag, we are going to get some additional future here minus a stands for ignore case since two. Now I can give up permit either uppercase our lawyer case. It doesn't care about it. Let me give the full uppercase permit. Okay? You can see here I have given full uppercase permit. Even though it is the uppercase permit, it is going to give the permit even though p caps and remaining small way because I just mentioned that ignore the case since two. This is how that grip command will work now we can embed 81 more feature with the grip. That is where pipe will come into the picture. So usually pipe is used toe combine two different comments in Lenox flat from Let's take an example that you're less minor. Sell. What does it to do? It is going to display the least off the directories. Whatever are there, instruct this one. I'm going toe some other directory. That is slash UTC. Okay. If you see here, you will have a lot off files under directly straight. You can see here a lot of files 100 Eric, please. But among these I want to check out particular filer Director exist or not? Let's take an example that environment filer directory exists or not. I want to check it out. If that is the case by using a less menace. L command and such ing here doesn't looks good. In this case, we can use the grip command. But as I said, grap will work only on filed diesel are not files, right? These are just two directories here. We can use the pipe symbol toe combined to this too. So ls my A c l. What does it happen? it is going to display the content, then pipe on grip investment. So in this case, what will happen? Whatever output you are getting with the previous command you to treat it as a file. This output treated as a file on the uber grip command is going toe. Take that as a file. Understand? Such for this particular word on you don't require your file name over here way Because you were previous output is their files Over here. You were previous Output is file over here. Let's exit. Go to this one. You can see here it is displaying only environment and you can see here it is a less menace . L command output rate. So this is how we can search for files are direct with within our system. And it was possible through the pipe symbol. So usually pipe is used to combine two different commands. Let's use one more example. That is, unless my cell, if you see there are lot off files. 100. Eric, listen, this particular directory okay? Where I am, I'm under E. T. C. Among this. I just want to separate only directories. I just want toe separate only directories in that case. What I can do ls minus l Piper Grip, I can give d right? Okay, Dean, Nothing. But wherever D is there, you can get those as output. But we'll see what will happen. You can see here. It gives the directories to also give the files which how that be wherever it finally it is going to display that one. Right? So this is the problem with this one. But we can just drink ill this common little bit That is by using that carrots symbol. This is carried symbol usually in cabled. It is safe to six safe to 16. Nothing but carrots. Symbol if you carried symbol What does it mean? That you were gripped? Command is going toe such for d on. This day should be starting off Neverland. You can see here in this files wherever the starting off lane. How d it is going to get that particular directory now? Let's enter. You can see here You get only direct this way because it is going toe such for the day. But the day should be starting character. A fever line Starting character You were land. That is how the character symbol will work. Now, let's exclude this carrot symbol on your file as well. Let me clear the screen on going back to my home directory. That is Syria tilled Peter Bloody Unless and here we have your file one. Great. So here, this is starting with that. The raid. I fight. Grip. Okay, file one. It is going to display the two lands way because it won't dirty here t here as well. If I give you grip. Cat it. Okay. Filed one. It is going to display the where that is the starting character of fewer file. So this is how we can use the grip command. These are the quite commonly used comments in the grip. That's all for this lecture. See you in that next lecture. 19. L19 - Replace a Word in a File - Commands: sed: Hello, folks. Welcome back in this lecture we are going to see said Command the city's terms for stream editor which is used to such a word in your file and replace with the new word required Toby in the output. Usually it is going to replace the world a text veto, the new takes. But it will only modify the output. But there will be no change in the original file means by default it won't change the original file. So let's see the examples. Yes City Yes slash Nothing but such older text slash new text on file them now it is going toe such for this world, the text of pattern wherever it find all the text it is going to replace with the new text What we do here in this particular file next to command yes, city such for world or text and replace with the new text on G. J. Stern's for global difference between this commander and this command is if it find the world text alone deal only it can able to change it. If it is part off your word, then it won't change. For example, I want to change high with Hello. Then it would find the high dedicated Lee. Then only it is going to change with the hello. But in this case, if high is part off some other words still it is going to replace. So that is the option with Reggie. Next thing. Yes, Siri. Minus a slash is well detection. New texture and find them. This is going to replace world. It takes with the new text andare Baird the file. Okay, It is not going to just to display in the output. It is going to update the file. Next thing yes, suit in my innocent fight or 10 p filing means it is going to display fight or 10 lanes off your particular files specifically. And usually we are goingto display. Veto the tail and head right Those commands going toe display only hair dark tale in between. If you need some lens, then we can use this common. But still we cannot you, by using those to command says Well then yes, you depend 20 deep file name nothing. But it removes that 10 20 lines in here file on the remaining It is going to display. Let's see in the action This is my Lennox system. I have logged in as root and I'm under root and currently deserve the files we help now, though, the monster this example. I'm going to create some text for that one. I'm going to search for answers. We'll see if the file for your information if you don't know and spilled at sea of DFL and splits the conflagration management It'll I have your dedicate, er courts on answerable. If you would like to learn about it, please go through with that course. Moreover, this is also from redhead. If you see here it is saying example file is available on get help. We are just grabbing it. So this is the file, but we don't need complete fell. I'm going to grab only few lines so that it would be easy around the 20 Lindsay I'm grabbing earned copy it into our fight. So I'm copying in over filed one yourself. So existing content, it is going to replace me to this new content. That's it. And ah, let me clear the screen on cat pile whenever you open it, you can see here it starts with nearly all parameters and the ends with the remote system. Okay. If you see here in this there is answerable, answerable, danceable, answerable like this we have answerable in so many locations. Now I would like to change answerable with Lennox. If that is the case, we can use our a Siri command as your Siri. Yes, nothing but such. What do you want to change answerable with? I want to change you to Lennox. Okay. And bill with clinics And I'm not giving g for custom aren't filed one. So what does it happen? It is going to replace answerable with Lennox wherever it find it dedicated and school work you can see here it is replaced with answerable with the Lennox. If you compare with the previous output, you can see here there is answerable minus playbook. It treated this as a separate world. It won't replace this world because is caps over here. Okay, here to detention on danceable conflict. This is also a per case so it won't change on the next thing. If you see here, this is dark danceable dot c of G. If it is just danceable, it might try to replace it. But it is dark, danceable, so it won't replace on the here it replaced. You can see here, answerable, replaced with Lennox on the next one again answerable Darcy of just so it won't replace like this. It is going to search for only answerable on wherever it finds it. Replaced with the answerable with Lennox. That's how it works. Now I want to change these kind off words also. Okay, you can see here and spilled out. CNG answerable. Dark, danceable. Darcy of J. All these I want to replace. If that is the case, you just need to add Gee option. Okay, so now you can see it has replaced everything. Lennox and Dark Lennox here also Lennox here also Lennix everywhere it replaced because it's still considered. If our answer will is part off your word again, it is a case and still so it won't replace these words because the cases to doesn't match. Now you want to try veto the case since two as well. Then you can use with G the region option called I nothing but ignore case since two. Let's see now you can see even though it is the upper Cassie, it has been troop list on all this stuff doesn't actually going to change your actual fell . If I open my actual file, it is still are the words in a level because it will only replace the output off the file, not in the actual pile. Okay, Now I want to change the actual file. Then you can use minus a option. OK, minus a option Crust will try every thought I g just with a yes so that only to replace ner wherever it finds answerable alone. Here it is the A minus. So it can start this as a separate word. But it is not considering this is a separate world again. This constructor is the separate word on this as well. This says, Well okay, let's exuded and you can see there is no put. But if I opened my file now you can see that changes in the actual file here it replaced answerable with clinics here also to replace the answer belittle annex here as well. So like this It is going to change now. I want to change with the global option global nothing. But I want to change the dark, danceable as well. So let's try one more time with G option. And if I open my friend this time it changes in between off our land. Now try with case since two as well with i options. So it replaced the very worried finds answerable everything it replaces with the New World . Alright, that is how it works. Next to command is just I want to display the faster fighter 10 lanes. If that is the case, If you see the 50 Lenny's, find the first under en suite. Invent rating your ends with inventory. Let's display that one. Yes, Siri. Minus in. Okay. Nothing but a number. Fire toe, 10 p. Okay. Didn't silent. You can see here. It starts with the fine first, Then it ends with their defaults. Not with today in wintry. Okay, there's a lotta violence 5 to 10 similar way. If I want to day late specific wards in the file, Nothing. But if you want to delete you just to give the deal it we don't need the end for this comment. Let's execute. Andi will display the interface except to fight or 10 lines. Nothing but these lines. You are not going to see in the output off a lot of folks. Let's six. Good. Now you can see it is started with the nearly all perimeters. But in between, these lines are Bolin's got disappeared because we have given the de option over here. So fight or relented disappeared. I can still give 15 or 20 if I give 20 you can see here it starts Little. Nearly all parameters on the remote system. It ends and you don't require. So this is how it works. One more thing you can try with their city commanders. You can replace. Let me open the file one. So we want to remove the hash. Then what we can do. We can just give the a city yes slash hash slash Just empty space slash and close on file. But now you can see here you are replacing with the hash with just empty space. So this is how we can replace the word in your file. That's all for this lecture and see you in the next video 20. L20 - Creating & Managing a User - Command useradd: Hello, folks, welcome back in this section, we are going to see how can we manage our users. So this is a user management section here. We are going to see how can we manage our users under how the permissions works on what and all things we do. Let's start in Lenox. There are three types off users. When is Super user our route user? This user is the most powerful user. He is the administrative user. Even in our Lennox system, we are working as the root user and we will have enough privileges to do any activity. Next. The system users these users created by the software are applications this user created whenever we are installing some software, are. When we are sitting a power system these users get create next normal user. Normal users are the users created by a road user. So these users, we are going to create as the root user and we can create any number off users. Of course, on your system. Now, if we want to see the example, Super user root user is the super user, and he is having a slash route as a home directory on his shell is slash been Bash. Let's go and check it out. Our super user This is my Lennox system right here. If you see I am under slash route only figure who we are. My It tells you that I am your route on my home directories slash route If you want to know more about this user, just do I d root It'll tell. See that? What is your use? Ready Group ready on which groups do you belongs to Onda. All the users related information is stored under slash CTC password Okay, this is the file slash C D. C. P s is the bloody if you check There are lot off users and it starts with Ruto being demon at many lp sink share Don't heart male like this So many are there right? And at last easy two minutes User, this is your additional user which is created on only AWS systems to log in as it to Lyon as a normal user. All right, Next to think super user ftp associates Apache If we install Apache software in our system , we get this user. This will have this directory slash where ftp and so on on the login. You cannot. How the shell for these systems, that's way yes. Been no large in it will come on at last. Normal user, we can create any user like a visitor. Easy to minus user. They are going to get your home directory under slash home and you with user name on the Daschle is slash been Boesch Shell Nothing but the prompt where we are executing comments, that is about users. So now we'll see. How can we create your user in Lenox whenever user is created in Lenox below Things happened very felt. Your home territory is created under slash home slash user name, then unique You a D and G 80 are given to the user. You will this transfer use already Generous transfer group Ready an entry in this class it Easy password. These things will happen now Watch the command to create a user So we have your commander to create a user that is indexed for creating an user inlay nexus user add options and user men. So these are the options which we can use Nothing. But if you want to change, use ready. Are you want to become your part off Group Primary Group Home Directory. If you want to change the home directory comment, shall these all of the options are there, but it is. All are self explanatory. Let's create your user first, I'm creating a user called Clear the Screen User Add John, I'm creating a user called John Andi. As I said, whenever we create a user first it is going to create a home directory. You can see here. Yeah, Home Directory has been created for John and also I d John you fig you. He will have one. You ready under G 80 So for route, it is Giron Jura. But for users it starts with 2000. He is a second user because, fast user, we have easy to minus user. So we got one double Gerawan even group also seem and he is part of group. Whenever we created a user by default with the same name, one group get creates and the user added, as part of that group Next thing again, I'm going to create one more user user. Add mark the only place he again, unless you can see one more directly has been created on the I D market Fake check. You can see Mark got one double Giro to even He got group aerial. So one double gelato and one group has been created. Now he's part up only Market group on. Same thing you can check out under slash C D C. P A system bloody. This is where the interests happens. You can see here, John. User on the excess transfer. You haven't set up the password for this user. That is the entry on one double Jiro One and same thing and slash home. John, this is the use that so that this is the home territory and he got this shell. This is how we can create users and groups are part off cats Lancet, easyGroup There is it file called Group. And whenever we create any user by default for the users, the group also get creative. No. Now 11 change I'm going to do I want toe ad mark. Also in the John Group mark also in the John Group. If that is the case, we are going to use the command called User Mart user. Marty's a commander to change the user. Marty's a commander toe change the existing configuration off you use Change the existing existing attributes off the user. And if you see here And if you see here to change the group, you need to use the minus. Gee option So minus G. I'm going to change the group User Mart earned. Ah, John, I want to add John Group. Okay, group name is Generate. This is group name on. I'm adding mark to John Group now let's enter. And if I do I d Mark you can see now. Earlier Mark was only part off only Mark group. Now he is also part off John Group. This is how we can add user to the another group. All right, now, when do we use this comment? Usually if I take an example during darker class, if I take an example during darker classes So usually when do we use during Dr Set up? We said during Dr Set up we should our user toe the doctor group So then we were going to use this option on also we can change the use ready by you. Sorry. User home their treatment by using minus d option like that we can do alright Darcel for this lecture. All right, That's all for this lecture in next lecture. We are going to set up the password for this user on blogging as a user. Thanks for watching to you in the next video. 21. L21 - Login as a User onto EC2 Instance: Hello. Friends will come back in previous lecture. We helped create it to users. That is one user is John. Another one is Mark. Let me clear the screen. And if you look at e d c. P s sister bloody, you can see the users 100 Now I want to log in as John User to log in as a user. You should set up your password. So I'm creating a password for this user to create a password you need to use PSS the beauty under John on password. I'm just giving again, John. It is easy for us to remember. That's it. I have set up the password for that John User. Now, if I open slash C d c password No, you can see here, John. User password We have set up. Let's try to log in his agent. But if we are using it notably a server, then we need to do some additional conflagration changes to log in as a user. First, let's log in as a user. Fission? Yes, a church on the Let me grab the I P address. So this is the I P address. Provide A period was over here and work it to connect are you can give the user name here as well. Now it is prompting for user name. I'm giving John as my user. And you can see here No supporter attended cation method available public e soon. So what does it trying to say is by default an easy two instance. Arlo, only key based authentication. You are going to understand what is key based authentication. Key based authentication. Nothing. But we need to provide our private key. But we don't have any private key for John User. We have one lee password. So we should do some changes in our system so that your user can use his password. Rather. Dania key. For that, we are going toe a duty. A configuration fell. Now I know that is E T C s a shit associated e underscore conflict. So this is how we can edit rate we can use Nano RV Editor. This is the default essentially configuration. You can understand. That's a stated in the letter. When we are talking about services on the India's check for one perimeter, you can see here password authentication. This is no nothing. But we are not allowing users to use the password. I just need to change it. Toe. Yes. Password authentication Toe s under to write out control. War Enter under control X to exit. That's it. I have editor. My default configuration toe alot users to use password based at indication. Usually whenever we update any configurations, we need to update our services. So I'm going to use this service. It's a city of reload. Even you can understand this command in the late positions. Let's just to restart it. Sorry, Reloaded. Once we have done, I'm going toe restart. Decision to restart decision. We can use our option. So I'm just giving our now again. It is asking further use that them. I'm giving user name and you can see this time it is asking for password. I have provided my password under. Do you want to save the password off John? No, I don't want to sell And you can see now I logged in as a john user and you played guilt. Who? Young may excess. John on the Peter bloody you can see slash home, John, this is the home directory for the job. This is how we can log in as a user on toe. Easy to instance. Thanks for watching and see you in the next video. 22. L22 - ls Command Explained: Hello. France will come back in previous lectures we have seen. How can we create a user under? How can we log in as a user onto our server? In this lecture, we are going to talk about our ls command. So whenever we do, the a less command you can just to see what Kendall files are directly in our current adultery. But there is no files 100 directors because John User is a new user. Andi, he hasn't created any files. Here, let me create your file. Touch file one. So I'm creating your file one even. We have one file one under root User's home directory. Now we logged in Asia, John User and we are creating under slash Home John are earlier. One is slash route only. Now, if I do ls again, you can see the file. And also we can use Ellis. Minus hill are a little right, and you can see the output. We haven't to discuss the board this output yet, So to understand this output first we need to understand the border part missions how the permissions does work. So I'm just locked in as it John user on for better understanding. I have already locked in as it grew to user as well under clear the screen. And if I goto Peter bloody, I'm under home directory. I'm going back to my home directory toe. Go back to home directory, Serie till weekend, you. And if I do? Peter bloody I'm under route here also. We have few files. Okay, on there is a little difference that will put what you can see you over here. And what You can see what we're here. But you can understand anyway. First, let's understand the permissions file permissions permissions are applied are three levels . One is Warner, our user level group level on others level. Let's go on that. Play this one to our file one, which we created under John's Home Directory. If you see here, this file one is created by user called John. This will tell you that who created this will on this is tells a Borda which group does he belongs to? John belongs to you, John. Group on others. We are going to understand any well before understanding others. Let's understand about this output. So permissions are applied in three ways. One is our r stands for read only next. W W stands for right. Edit a pinned under Deal it next x exist. Answer. Exude Iran So you can play the permissions only in these three levels. On If we go and check out our output, you can see here. Read rate. Really great. Read. There is no execution permission. Settle on that. If I go back to my roots directly here also, you can see here. Really great. Execute Really eggs Good to relax. A good rate like this. The permissions are there. So here it talks about the read permission and write permission. Let's understand more clearly about how does it work on your file Under air directly in UNIX. Arlen X files How eight attributes that can be seen in a less menace. L comment so similar kind of output we are able to see here. We are going to talk about this fast, Doctor. But if we take this one in detailed one, it will have the four parts in this world. It has the four parts so fast apart. Attacks a Borda. What kind of file it is. I already discussed that if it is minus, it means in our multiple. If it is d, it is a directory. So 1st 1 tax aboard the file name. Okay, talks a border file type. Let's see what kind of files are there in over UNIX operating system. Here we help file types. Minus are hype on stands for Marmol Fell B stands for block fell like hard disk are floppy disks. We call the jib block file systems for character fells like keyboard. Most these times fanatically yell stands for link rails. Okay, these are the different kind of files available in the Lenox operating system. Now let's go back again. Okay, so 1st 1 will talks about a 30. The miners are B B C. Yell anyone off? This will be here. Depends upon this weekend. I don't way what kind of pilot is next to talks about permissions off the Warner after file . So in this case, file one is created by the root user right here route. So this talks about the root user permission. What kind of permission he is having on this file on? This should be in the order. Nothing but first character must talks about only read. Either it will be our barrels minus second character is either W are minors. Tar Character. Either X are minors, so it should be in the same format in this case, one. Or how their read write execution permission on this. Well, he can do anything. Let's more onto the next part. This part is talks about the group permissions group. Nothing but route is the winner of this failed on. Also, he belongs to the root group, apart from Root User. If any other users are there in the root group, what kind of permissions they're going to get? They get a real underwrite permission, but they don't get execution permission. No others, others nothing but who is not created this well and who is not part off this group. Then what kind of permissions does he get? They are going to get real permission. So something like this. Second, Part two talks about the Warner Permission started part of talks about the primary group permissions on fourth Apart attacks over the other's permission. Next, let's take another example in this example. I want to access this file as year user called Mark. We create area mark user and we added him toe the John Group right. So if we talk about the mark second part really great execution it is comes to for the Warner. So who is the winner? John Market doesn't come under to displace. Next thing is group permissions. What is the group named John is marked part off the John Group. Yes, off course. So Mark is going to get their read write permission on the next thing is others is marked part off the John Group or not, He is already part of the John Group, so it is applicable. So this is not valued for the mark. But if I take the same example as the easy to minus user prospect, if that is the case, so faster thing is not applicable because John is the winner of this world. And second thing also is not applicable because you see two men issues. There is not part of the John group on it. Commanders to the others. Because because you see two men issues, there is others. That is how the permissions does work. Now, let's tested this one with that administration. So to demonstrate this one, I'm also setting up the password for Mark as a root user mark I'm giving possible as a mark . No, let me log in as your mark as well. This is Hitch. I'm grabbing my I P address. He is not quit. So I'm just liking as a marquee with that right? This time it is not asking for user because we have already provided and password also, Mark. No, I don't want to sell my password. So now a how logged in as a mark. And if you see Peter bloody and belongs to the slash home mark group what I have done, I helped create the Apostle for Mark. So I logged in as a mark user and clear the screen. And here also I had logged in as a john user. And again, this is a root user. Now what I will do, I will create a file as a john user. So to create a file, I'm going toe TMP because TMP directory is accessible by everyone. If I create a file under my home directory except the super users, others cannot able to access. So I came here unless only few files are there. I'm going to create a file toe touch filed toe. Okay. And if you see here you got permissions like real Graito or not nothing but for John User and relate to John Group People even markets part off John Group. For others, it is only real excess. Like you see, two main issues it now I will add some contento this one cat file too. Hello? Welcome, Mark. Okay, I'm just giving that is it. I put That's okay. So I helped her in Welcome, Mark. I can ableto open this file now. I'm sifting as a mark user. Even I'm going toe slash TMP I could see the same files on defy tried toe Open this file. I can ableto open way because I have read permission because if I do, I d I'm also part off mark group as well as the John Group, so I can ableto open this will next perimeter. If you see I have also write permission. Found some problem over here. Andi, I can edit it with the V a r nan also So I'm just going to read it. Welcome, Mark. Okay, so now you played See the file to you can see the update or content way because he has the right permission to experiment This one. Ah, little more Better. I will log in as a easy to minus user as well. So she shin It's a church and I p address for the easy to Manus user. I don't help password So I'm just learning to keep it. I only see two minus user. I'm going in circles. Last TMP and even here I found that file photo and let me open the file to and you can see here I can able to read because I held read permission I'm not Belongs to the John group on I'm not also wandered off this way. Let me try to edit it with the V a child toe. You can see the sea here read Only you can just open in Eric more. But you can still see that read only we'll save Well. You are trying to say this Well, you cannot able to do that one so you can see here Chaining is not possible. We're getting as easy to minus user Onder, let me say this well and you can see here read only option is set. It won't Ah, laws to right. So just I'm skipping this one again If I open this well cat file too. You can still doesn't see if I try to update this well with the cat file toe. Still, you can sit up permission denied our way because you have only read permission as it easy to minus user. But if I tried as a root user, as they said, route is a super user rate for him. These permissions doesn't applicable. He has full access. I can ableto get this file. I can ableto upended this file. Anything I can do because I'm here rule to use. Okay, this is how permissions books on your file. You can see here deserve the permissions. Alright, thanks for watching in next week. Do we are going to see that remaining stuff? 23. L23 - File Permissions: Hello, friends. Welcome back. In previous lecture, we understood how the permissions works. Now we'll see the remaining all perimeters. This is how the output is. Next thing we'll talk about the filings we rarely use aboard this one. Then Warner after file and Oneness primary group undersize sizing boats on the date window file has been created are updated if you update the file dubbed later date comes over here on the final. So this is the full definition off particular land. So far, we are talking about these permissions in the prospect You off your file now other stock in the prospect of warfare directory. So if you see here whenever we give the real permission on your file, it whoa opens a file. Nothing. But we can able to read the file whenever we do the real permission on your directory. It means that you can ls under particular directory. If you do, ls you can able to see the content next to think. Next. Two things, right? Permission. Whenever you do the right permission, you can able to write a did upend deleted the file. If you give the right permission on your directly, you can add delete. Rename the contents off directly. Nothing but within your directly. We may have directories and felt threat. Those names we can. Margaret. Next execution to run your commander cell scrip Usually whenever we run yourself Script we are going to use execution permission here. Execution permission mints to enter inside. So you were directly by using your Siri comment. Now let's experiment with the directory level. If you see here, I'm your John user. Currently I'm under TMP. I'm sifting back to my home that every city slash till now. I am under my home directly. Whenever I do, you're less minor cell. Whatever files insert my directory those files information has displayed. But if I want to see my directly permission then I can use a less minus cld followed by You were directly It gives the permission. Saw fewer directory. You can see here Permissions are fewer Directory Nothing but slash home. John, be really great. Execute nothing but John can ableto do ls on this directly. That is the reason really is there and John can ableto create, are modified or deleted the directories. That is what the blue permission talks about. John can come inside toe this territory that is the execution permission talks about right now. If I tried to come toe this directly as a mark user, let's see what will happen. Markets. They're not wander off this particular directory so this permissions doesn't applicable. Then these three permissions are applicable under for group. I mean to say whoever adds to the John Group, there doesn't have any permission. So markets apart off John Group and he is trying to go inside to slash home John, and you can see here permission denied way because you don't have permission to going, say toe the John's Home Directory. Similar way as a easy to user. If I try to go inside to John's Home Directory, even I get the permission to unite. But as the root user, if I try the same thing, I don't have any restrictions. I can go to the John's home directly, and even I can create the content as well file to, and you can see here you have created file toe under John's Home Directory, and if I do ls minus l. You are under chance Home Directory. This particular file is created by John User on this file is created by root user. That's how the permissions works on your directory. In next class, we are going to see how can we change the permissions off here? File our directory. Thanks for watching. See you there. 24. L24 - Changing Permissions - Commands: chmod: Hello friends. Welcome back in this lecture we are going to talk about file permissions. Nothing. But how can we change permissions on your file or directory? Permissions can be set on any filer directly by using two metres when it's symbolic. Mattered nothing but you gv will These options we can use another one is absolute method By using numbers, Buster will see the symbolic method The commander to change the permission sees See hitch more next to who? Nothing but whom you want to give the permission then plus or minus are equal under permissions. Nothing. But what permissions do you want to add? Are what permissions do you want to remove our what permissions you want toe overrate. This will give the information for example, If you see See how much more you easy called you Stands for user are Warner right? You equal to read right? Execute it talks about owner permission Comma Jeezy Court reiterate nothing but grew permissions. Next boys equaled. Really? Let's quickly execute this one. I'm me John User. I'm under my home directory At this moment I have two files and the one file is created by me. Another one is created by route off course. I cannot ableto a data file which is created by route because I'm not belongs to year route group are I'm not the one hour off this Well, so I commander toe the others So I get only read permission. Of course, nothing is there on this file. But let me try to open on defy tried toe Edit this one by using cat command you can see permission dinner so I can do the changes only on my file on my file. I would like to give the really great exertion permission to everyone in that case, we can use. Thus he hatch more. You use terms for user? Nothing but my permissions. Currently I help Really great permission Even I want to get execution permission. Then I can give you plus X plus six. Nothing Good user is going to get execution permission on this. Well, ok, let's see if I don't space very mining stock. It doesn't touch the remaining permissions. And if I do ls minus l r. Earlier it was having only read Right now I have given execution permission with the deception. Now I want to remove the right permission to my group members. Then I can do. I'm going to get execution permission anywhere. But it is already there. G minus w nothing but for group I'm removing that execution permission next. Well, we'll get only real permission. So here I'm trying to include a different way south for presenting the permissions. Whenever you do place, it is going to are the permission whenever you give minus, it is going to remove the permission whenever you give equal. But our permissions are there. It just over rates. With that this permissions instead of freed and giving doublet so that you can see the changes. Now let's execute and lily Fig you you can see here Our Lear root user is having real great execution Now also, he is having same permission because we just given that you place X Next thing is group Earlier group was having really read permission. So now he is only having root. Sorry. Read because we removed the right permission are earlier this gay was having only read permission. Nothing but others. But we ascend Whatever permissions are there, remove all those permissions. And as in the new permissions, that is the meaning off equals. So you got the wounded. All right. Permission. That's how you can change the permissions by using symbolic method. Same thing can be achievable by using the absolute method. Let's go on to have your look. So this is absolute method. We use numbers in, showed off using symbols How we can, as in the permissions over here similar. We're here. We use numbers. If we want to give the real permission. It is for if it is right, then two. If it is execution, then one So ch more. 764 Followed by filing him so fast. Character talks about Warner off the file. This is group off the file. This is others. So here we are, giving seven minutes four plus two plus one. Nothing. But I'm going to get rid. Right? Exude six minutes for place to I'm going to get re read. Permission for means it is only real permission you are going to get If I do three, then you get a real and execute. If it is to, then you get only read permission. If it is one exhibition permission, that's how it changes. So let's exhibit this comments now. I want to change the permissions on the file one itself. So see how much more? 666 I'm giving file 1666 Nothing. But you get a really great really great, Really great Because four place to read. And if we do a less minus yell, you can see really great of you Trade reiterated. If I do see hatch more 755 you are going to get really takes a good under here. Really exude way because fire means four place one great for nothing but read place one means execution on file one. And if you see the changes again this time I got really great takes. Good. These guys got really executed exude similarly I can give See Hit more Triple seven. It should be three letters. So I'm giving full permission to everyone. Triple seven. Nothing but full permission. Everybody. How that read, right. Execution permissions. This is how we can grant permission on that last. If I do see how much more we have, Jiro also triple Jiro tripled urinating but no permissions under fail. Even though I'm warning off this file, I cannot ableto open if I try to do cat permission denied because even I don't have any permissions on this. Well, that is how you can change the permission. So see how much more? 644 I'm keeping back to the default permissions. So usually this is the default permission on your felt. Similarly, we will try to do the changes on your director away because earlier I was trying to log in tow slash home John User, I could not able to do that one. So let's change the permissions off the directory. If I give my directly, I have only relate execution for the John User. Now, I would like to Al Odah Mark also toe. Although mark inside I first I need to give the execution permission. Okay, so I'm going to change it. Ch more for me. Day seven on for John. I want to give only come in certain your directory. So then execution permission. Execution permission means one for other cities. Jiro on my directory. So my direct enemies slash home slash John dread Andi Moreover, only Warner off this file. Our route user can change the permissions by using the ch more ch more stands for change. The more now Let's execute only if I do a less minus D You can see here. Sorry, they're less menace led. You can see here. We got execution permission Now, if I try to log in as a mark, I should ableto go inside to the directory. Yes, I can. Now if I do a list, you can see here again. I got permission denied. Way because to really in Sadia directly, you should have read permission rate. So now again, I'm going to change the permissions for this one. I'm going to give execution place. Really as well for that Fire it. Five minutes for place, One real place execution and you can see here. No, if I do ls this time I can able to list or this one? Now if I try to create file three I could not ableto because to create a file I should have the right for mission on your directory. Then you should give us he hatch more seven so that you will get rid right? Execute Jiro on my home directory. No, let's go. If I try to do the same thing this time, I can able to create and you can see File three has been created as a mark user on this one because I have given permissions toe the mark user on my directory for do ls Menace Ellie. So group members can ableto come under do their activities. But if I try to do as they easy to menace user on this one, I have altered a luck denies Easy two minutes user. I can still not able to log into his home directory because I'm belongs to other users and belongs to other user so others doesn't have any permissions. This is how we can use the c hitch more commander to change the permissions on your plate at last. If I tried to change the permission suffer Mark User are this one I cannot ableto do not change See how much more just I'm trying to do triple seven and file toe you can see here operation not permitted because this is created by road user Same thing will happen if I try to do under Final three because it was it is created by Mark User. That's how you can give the file level our director level permissions four year user All right there cell for this video in next to where we are going to see how can we change the oneness of popular file? 25. L25 - Changing Ownership - Commands: chmod, file: Hello, friends. Welcome back in this lecture, we are going to see about how ch more commander does work. Also file command. Apart from this, we help Coward remaining all commands. Let's go and see. In my home directory, there are three different files. One is wounded by a John user. Another one is warned by root user. Next one is wounded by Mark User. Now, this is my home directory. I'm yet John under. I want to want all these plays. In that case, we can change the Warner ship off the file by using the ch one command. Okay, So see her Choo woon and to whom you want to give the permission. I want to give the permission to John. Find John. This is group. This is User Colon Group under the filing Unfired toe. I want to change the way ownership of your file to John User and John User. And if you see I'm training as a john user, I'm trying myself to one that particular file on. Let's see what happens. You can see changing one of super file toe operation not performed because ch wound can be executed as a root user. You cannot execute this as a user. Even this file is wounded by Margaret. So market tryto Gouda ownership off. This felt so that John on, We'll see what happens. See her worn John Coghlan, John, Because I loved it as a mark on 53 You can see it still, even though I'm warning off this file, I don't help our mission toe change The watership after file only root user can ableto do these kind of activities. So here I have logged in as a route on die already under slash home slash Johns earned the You quite try to change the permission. See how much more? So they see her to one John, Colin, John and filing him. So let's execute. And if I see now, this file is wound by John Usar Earlier, it was one of Beirut User, and ah, earlier I was trying to change the more off this file on file do. It was not permitting as a john user. Now I'm the one hour off that file I can change. The permissions were tried to exude same command which we trade in the previous lecture. You can see it worked now Triple seven permission got on file, Toe. This is how we can give the ownership on your file on DA. Next one is on file three. Also, I want to do one of 2.2 John, But if I am not giving group, you can see what happens. You can see only the Warner off. The file has been changed, but not the group off the file. Now, this particular file group is this one. These group people get this permission. That's how it works. But I'm going to change it as a user and group both to John. No, If I do a little, you can sit up. Permissions has been changed. Same thing is reflected over here. All right, so this is how we can use the ch more command. Next we can see the file command file. Demand is going toe Talk about what kind of file it is. If I do file file one, it says that ask you text nothing, but it is a normal text file on. If I do the same thing on your directory, let me create your directly and ah filed the air one. It tells that it is a directory similar way I said that we have different kind of files, right? If I go to slash deal, you're less. They're less menace. Yell, You can see here there is a character file block. Well, on the file on the Jiro on Julie breaks Good pile Command. You can see here character Special file because it is a see nothing but character special. Same thing you were doing. This one you can see it is a block file based on your block. Well on we have yell also right, Link Riffle. If I g o on this one file under on this. Well, it says that symbolic link will. This is how the file Command helps us. It tells us what kind of file it is. That's all for this lecture on to see you again in the next lecture. 26. L26 - Gather System Information - Commands: free, cpuinfo, uname etc..: Hello, friends. Welcome back in this lecture we are going to see a boat system Management comments. Let's start with the first command history History really start all the comments executor by that user. Whatever commenced we have executed under what system it is remembered by our operating system on we can restore those by using his recommend. So this is my Linux system, and I have locked in is a root user. And if I try to see what Kendall comments I have executed, I just need to exude he studied. You can see here. So far I have executed for 27 comments. Last command was history previous to that one ls pwd clear all these comments Even when I was changing the permissions in my previous lectures and the opening your cat file and ah, editing this essentially underscore conflict Will all this information is remembered by river system. Similarly, even I can execute as a user I have logged in as a john user. If we exclude history over here, it shows what a null comments I have executed as a john user. So, as a John user, I have excluded 96 comments on the diesel are the comments on? How does it remember these comments? If you see under rude, if I do ls minus jail. You can see only this wells on. Also, we have one more option. That is a less minuscule year. Yeah. Tribute is going to display the hidden fails. You can see here we have a few other hidden fells over here. Hidden files are starts with the dot. Even you can create your NFL touch dart trial 25 create. And if we're doing unless minus yell So, realist Manus El, you cannot see the file 20. But whenever you do ls minus Yulia. Then you can see the hidden files you can see here file 26. You don't feel like that. There is a There is a dark bash underscore history friend, which will store all these comments If I open this well, you can see all those comments. Okay, So that is how it remembers the comments. Next to command next to command free free is a command which will tell you about how much memory you have. Anyone system, if you do remember, while we were creating our system, we helped Susan T to micro in stands on UW's which will give one GB ram on one CPU. Let's go and check it out. I'm giving free. You can see here memory you got a total. This is in KBS. I think on doubt off this this much is used under this much is free our center this we have some other information. If I do free minus him, it will show you in that MB on DA 8:15 a.m. B's total MB Even though we have allocated one GB, we got only 8 15 MB out off that 1 61 MBI is used on three not sixties. Free on remaining is aquitted by some other process. That is how you can identify the memory Aram. And there is one more commander toe Find out the memory and for that it's last approx less Memin for just to give the cats less Brocks less memory and four you can see this is the memory information on the total memory. Even in the KB's, you can see and same whatever output rehearsing similar information is here similar way we can display our process for that Brock CPU in four CPU and four is the command to Norbert. How many process we help so you can see. Here we have Prosser. Jiro means it starts with Jiro. Of course. Germans. Only one processor. We hope that is genuine Intel earned. This is the mortal. All this information is there. So we have one CPO on this system. Right? Next unit minus here. This is unit minus Ed. Let me Correct. Okay, You named Minus C. Shows the colonel information. You name my last year. You can see here. It is saying that, Lennox, this is the I P. Address off. Over system. This is a Colonel Larson. And when was it updated? What is the carnal wash? Chinese city of 64 or 32 bit. And what is the operating system? All this information is displayed by using that you named minus yet on. Also, if you want to know about your operating system and a redhead, we house classy, dizzy redhead release. Okay, this will tell you the operating system washing. We are using Red Heart enterprises and exit released a doctor. So this is our operating system washing. Next. Do you okay? Do you tell Started excuses off your directory Currently, we are under router Directly here darted search directories Oxford Only four kb here also directly 14 kb directly to eight. Kb like this. It tells you that how much how Oxford on even you can convert it into the D U minus iam It will show you in the embassy's I can do with the directly that is. Do you do you mind? Awesome. Under slash CTC, it is going to display the slash CTC directory How much space it is consumed. There are so many files under this one. So it is giving all the all those files information on Do you have more options? You can use the man commander to check out on. We are using the, um, option. Right. You can see here, um lake block sizes, one MB to displace in the MBI. And also we can use the do u minus k under you were directly name. It tells you that how much space it is condemned in the in the KB's. Okay, Ondo. Usually we use the de humanise cape on there. Pipe sort of minus are in head. Okay, so this comment is goingto tell you most occupied top 10 files in the particular directly. Okay, sod command is not available. That's OK. But usually we used this kind of commenced to find out the disk retaliation off your system . Let me clear of the screen. Next to varies on which, where is common to tell you that we're exactly where command is installed under from where it is executing. If I give very Zeglis it to tell Sue that Ellis is available under dislocation under this location. So whenever we excluded, unless it goes and execute from here, us are built. Even rich also is good. A similar kind of output you can see here. This is the which and it is available under executing under this one's class. Years are been here less so. This will tell you very were particular application is installed. We are going to use these in the letter stations. One last comment That is DF command. This commander tells you that how many file systems are there on our system? File systems. Nothing worked like in our windows. See, Dr Deirdre, we will divert right similar way One hard way we can divert into multiple file systems on UNIX. So you want to see the file system names, you can use the D of command and ah, it will tell you that KB's if we give the d off minus iam If we give that DF minus iam, it is going to show you in the MBI on the each. Well, how many MBD is are compared on and how much is used. How much is available under uses percentages. All this information is displayed Anyway, we have only one disc that is 10 GB disk. This is split into this file systems. That's how it is there some for this lecture. See you in the next video. 27. L27 - Installating packages - Commands : yum [install, remove]: Hello. Friends will come back in this section. We are going to see the South Clear Management. How can we install our village packages are nowhere, Lennox system. Usually we are going to use, um commander to install packages. Let's understand what is him your miss primary tool for getting installing billeting quoting under managing red hat enterprise Olynyk software packages from official ready hard software repositories as well as other third party repositories. So, um is used to install packages are deleting packages, are courting nothing, but whether it is installed or not, this kind off activities we can do with William apart from, um, we how RPMs will But nobody's You can see when the Yemen commander to install packages. Let's see the example commence here. If you see Yemen, start back is name. This is the command to install packages. We use the, um, command on DA next. What activity do you want to do? You install, then pack his name. Which packets do you want to install? If we want to remove packages, we can use them removed. If already packages are installed on, you want to update it, toe the latest or send them young mobbed it back is name similar way. If you want to know the install the package information, then you mean for pack is name next, um list available bought in all packages are available on Red Hat Enterprise Lennix System . What is this? Raid had to impress Lennox Repository Mince it is the one after repository were read Had to team keep all the soffits in that repository. It's like Dr where they keep all the Southwest and you can exude tm commander toe pull under installing never local system before installing any package you can check whether this particular packages available under a repository are not. If it is available, then we can install it. Similar William list installed. This is going to displace the all the installed packages in the woods system. That is how we can exude this comments first, let's a private Yemen style command. So this is my Lennox system. I have already logged in as root user. If you do remember we how used low volume command sometime back. But let's try to execute again one motor. As I said, if we want to install any new package, we are going to use young install, followed by package name backers. Names can be anything. Assume that I want o install 100 packets in windows. We can just download the packers and extract it and install it. Right. Same thing, Um is going to download those packages and install an award system. Yum! Install on gyp. I'm installing Angie packages. If it is not there, it is going to install. Let's see whether it is installed or not is not there in our system. But it found in the red had repository. You can see here in this report it with this. Packages are available on the engine. Papac his name. This is our arc teacher X 86 64. Bit on. This is the washing off Angie packages and this is the size it is going to operate. So do we need to download and install it? Yes, I want to. And you can do Yes to install. Sorry. Noto, skip this one. So it's installed A No. Once it is installed, you can execute this particular command before installing. If you try to exude this command, it doesn't work. This is how you can install the packets. So yum install, followed by the Pakistan. Okay. Now, if you'll see this one, I have locked into the same system as a john user. If I try to do the same over here, um, install on gyp, you can see what will happen. It is saying that year this command has to run under the root user. So you must be a root user to install any installation commands because you are installing on system, right? So administrators can build these kind of activities. No. Let's try to insult one more packets before installing. Let me try to exude that, commander. Okay, three is the common. Okay. I think we have already installed a tree. No telling it. You can see. You can understand the purpose of this command later. But I'm trying to install command called the Telnet. But telling it is not in start. Let me install this packets. Yes. It found your back is under. This is the word chairman of the sister size. It requests. I want to install it now we fakes a good tell net. You can see this time it is not throwing error and it went to the telnet skin and you can exit from here quit. Okay, so crit is the commander to come out from the tell negotiation. This is how you can install on one more thing is the blue git. The command is not there, but you can understand. W get command later if you want to install Yemen's told a big it instead of giving way at that time off installation, you can space fate that one. Well, you run your commend itself if I do minus way. If it means that I'm accepting to install this particular package so it won't prompt again . Toe ask my permission to install No, I want to uninstall back is then, um but even more w get Okay. Sorry. Before executing, remove command Let me exude her. W get. And it should share that missing you are nothing but our Earlier it was saying that I don't know what you are typing Now it is saying that you are not typing in the right way. That is what it is trying to say No Yum. Remove. Okay, remove is the commander to dilutive Pakis Young removed obligate. I'm giving Yes, I want to remove. And now again, if I get exuded a bigger to this time It says that no such file or directory because we have already installed and removed. That's why it is giving this one. So this is how we can delete our packets in next lecture. We are going to see how can we update on the list? Our packages. Thanks for watching. See you there. 28. L28 - Updating and getting info about pacakges - Commands: yum [update, list, info]: Hello, friends. Welcome back. In previous lecture, we have seen how to install and remove packages. In this lecture, we are going to see how can we update on getting in four earned List those packages to update any packets. That package should be at the lawyer washing, but we don't have such kind of packages, I think because we have set up this system recently, almost all packages could be our latest level. But still, let's execute on. We'll see. How does it work? So young update Because we have installed it sometime. Back on, minus way. You can see here last meta data. So it's assumed so. And ah, dependencies resulted and nothing to do because there is no latest worsen for this one. Let me do the young updated a blue get and we'll see what happens. You can see this packers yourself is not available because we removed in our previously lecture itself. That's how we can execute, um, update. But usually if packages that lawyer washing you want updated to the latest we're sending, you can use the update No young in fort to find out information about your command. So you mean for three if we do, it is going to give the information about your particular command. This is the back his name under this is the wash in on day release. This is the release our teacher size all the information about your packets. Same thing if I try to do on. You mean for the blue get You can see this is the blue get package information it pulled from the redhead re positively. Now I would like to check whether the particular packages installed are not then young list . Um, list installed is going to list all the packages. Let me exude it First you can see here all these packages are really stood out. But from this I want to just to get the whether the big it is installed or not, you can see here um list installed grip, public it and it is not installed. If I do the same thing you list installed grip tree three is already installed and you can see the three which watchin it is on from which repository it has been pulled. That's how you can find out and ah in slough installed If I do available, available So whenever we say installed it is going to check in my local system. It is going to check in my local system. But whenever we say available, it is going to check in the repository which we help connector. Nothing. But in this repository it is going to check. So let's see trees there are not. Of course it is their tree. But it's such for wherever three finds all the three information it is displaying similar way for tryto do that w gate w get also dead in the repository rate. It should display the information about the blue get you can see here w get it is still not installed, but it is available in the repository. That is how the young comments are useful to find or the package is We are going to use him in the going forward classes. There. You can understand more detail e in regional situations. We use their cell for this lecture and see you in the next lecture 29. L29 - Collect Network info - Commands: hostname, ping, wget, ifcofnig, curl: Hello, friends. Welcome back in this lecture, we're going to see network and related stuff and we help you comments, which we commonly use in the networking level. Those are listed over here. Let's starts with Horstmann. All right? This is my Linux system under how logged in as a root user. Now let's execute horse name, host name usually going to give the name of fever server. So this is the name of our server. This is how default name looks like for your server. This information is stored under car TDC host name. This is the file were host. Name is updated. You can see here the content off this one and I can able to read this one by using horse name. For now. You can abduct this horse named by reading this file. Okay? We ate on the host name and you can remove and you can give whatever name you want, Lennox Sarwer. I want to kill. Once you have given it, you can save it. And again, if you're display the content of this file, you can see the Lennox R but host name if I give it still maps to the previous one But if you want to get this horse name, then you need toe restarted. What system? They only it can able to read the content off slash CTC host name. Otherwise it it won't be happened. But instantly. You want to see your horse name? If that is the case, you can ableto eggs. A good host name space. You were Sarwar name. If you give this one, it is going to change your host name instantly. Now if I go horse name you can see here Lennox are on this particular command is temporary Nothing. But if you re starting with system again, it reset to the whatever value is there in the host name pile. That's the reason we have updated in our host name fell as well. As for time being, we have updated our host name temporarily For now. Lennox surgeries the server name. And if I restart my system, it reads from the this well again. It changed to the Lenox are over. That's how it works. Okay. To restart your system, you can use in its six in its six is the commander toe restarted. What system? Okay, so let's pray and it has been connection closed on the unit six ari, but also does work to restart your system. And it'll take you a minute toe come up because it is restarting on. And I'm going toe press R to restart the station so that if the salaries up it is going to communicate and, uh, display lower here. Okay, Now you can see here I have logged into my system. My system name has been changed to Lennox Server on the flag You host name? You can see my host name has been changed to learning system, but dont change host Name off your system when you are in real time world because it has some DNS names. If you change this name, it may not communicate with the external network because yes, while using host name Common on Moreover, I have logged in as a U C to minus user. I want to see if to toe root user for that I should use the Sud Well Yes, U minus So that I can log in a zero. Clear the screen now let's takes good. Another command that is pink. I p address soaping is a command to check out whether the target system is available are not bring google dot com. Okay, google dot com is a website, right? Whenever I think toe the google that come from this system Google that come is reachable are not if it is reachable. This is how you are going to get the response control, See to stop it and you can see here, Tim packages transmitted on the 15 received Jiro packet loss. Nothing but this Sarwar is accessible without any issue. What do you do? Server? Because google dot com is the application, but it is running on some server, right? This is the I P. Address that particular server. Okay, so this is how we can check out whether target system is up and running or not. Deputies shut down. You cannot table topping to the server. If you are losing these connections, then the surgery is not available to access. If I try to give some might be like tender to $20.30 dollars party, I don't know whether it is available or not. You can see here it is trying to connect with that system and ah, there is no proper communication established and seven packets transmitter Jiro received 100% package last. Nothing but this targets are over either. It is not available. Art. It is in shadow Monster. That's how you can find out by using the pin comment. So this is the quite common command which we use to check out whether others are over is accessible from this network are not. And if it is in the same network, whether their salaries up and running or not, next w get so you know, our previous like ships. We have seen that w it command the blogger command is user to don't lure packages. Let's take an example that you want to install Tomcat on your windows system. Then what you can do. You can go to the Tomcat Web site and download the packages and install it on your windows system so that you can set up in our window system. Same thing if you want to Do you need to don't know those packages until the next system as well. If that is the case, we can download it from Don't Lord Tomcat and it goes to the time get off his shell website . And if you scroll down here, you have been a redistribution. You can just don't load it. If I click over here, it is going to download. These packages can see here you are downloading it, but I don't want to download it onto windows. I want to download it on toe Lennox system. Then what you can do? You can just to take it as a right click on copy Link address. Copy. Link Address is going toe capita link off this file. And you, Can you? This is the link only. What? Downloading this packages. So w get is going to download these packages. Okay, w get is not installed. Let's install W get. Yes, I want to start earned w get packages back, isn't it? So it is going toe Don't, Lord that particular packages onto your system How you can see under downloads similar way You can see where you held on Lord I have downloaded in my current working directory and you can see Apache Tomcat packages don't loaded onto you were Lennox system. So for this kind of activities, we use the blue get command next. If conflict you've config is a commander toe find or the i p address. Opulent system. Okay. If conflict is the commander to I didn't play the I P address off your system. You can see here. You were sort of r I p addresses 1 $72. 31.7 about 1 56 Sometimes we may have more than one I p address. That's not your problem, because it could be for redundancy or some other purpose. But any AP could work to connect to that system. So this is the I peered yourself. Our system, even you can use I p 80 Dear Commander Toe list or Di Pietro's. There is a Lubeck address. We don't need this one. We just need to concentrate on this one. So this is our i p address. Okay. Next to one. Even we can eggs. Good. If conflict minus he also. Okay, if conflict minus E is not working, all right, That is how we can. I didn't say that. I appear to suffer our system. Next total net. We are going to talk about a telnet in the next lecture on the next Carla Carlos to access our application as a browser. So I assume that I want to just access the Google website. Then I can do Google that can. Right? So similar way If I want to do let me close this similar way If I want to do on my Windows system I can do that, Carl. Carl, google dot com. Okay, so you can see here. This is google dot com and this is the default home page of fewer Google that come. What is the use of Carl Command? Once you have deployed, they were application. You just want to check from your local system Whether it is accessible are not for that purpose. We are going to use the total you can understand aboard the Carl Command when we are doing the heads to DPS installation. All right, that's all for this lecture on to see you in the next lecture. 30. L30 - Telnet explained : Hello, friends. Welcome back in this lecture, we are quickly going toward rent. Where? What is Port number and I P address? Yes. You already know eats are what has when I peered us. Right. So this is my servant I p address off course in AWS. We have to I pertussis when his public and private eye pertussis so public is optional. But if you want to connect from Internet, you should help public AP address. Otherwise private I p address is sufficient. But anyway, just a gym that we heard to a piece for the system. But each system requests at least one I p interest I peered was nothing but identification number off that server in your server. We can run applications applications. Maybe one are. It can be multiple. Let's take an example. We have one room in that room. We have multiple lockers. Each locker can be used by a different person. In this case, just a gym. That locker is the application. It means that in your server we can run multiple applications. But each locker How? The identification number. Right? So in which locker? Who state eyes there are in your locker. Whose content is that same thing is going to happen over here in your server, we can run multiple applications, but each application has toe identified with one number. That number we call that support number. It means 30 India Server, each application run Sanya Port number. There are port numbers from 0 to 65,000. Place. You can use any port. Remember to run your application. It's like a containing a room with Jiro to 65,000 place lockers. You can use any locker to keep your data. Some services runs on default. Porter numbers nothing. But for this application, this is the pore to number like that If you see this other important port to members under the services. If you see FTP service, it runs on port number 21. If it is, associated runs on port number 22. Tell Net 23 SMTP 25 d Innis 53 hits. Two D p. 80 hits to DPS for 43 Like this, we have some default reporter numbers for each applications. Now I want to check in my system. How many applications are running on the on which port it is running. If you want to know about that one. Just execute this Commander Net to start minus two U L p n Okay, so this is the commander to check out which ports are used are which ports are used in your system on which applications are already running. You can just to see whatever is in listening state, those are occupied. That is the meaning of this one. If you see here, Port number 22 this is the I. P address. This is port number. It means that I can access this particular service from anywhere. Of course. So this 20 it'll port member is user way? Yes, it's huge. Disservice. This 22 port member is usually associated with service. That is the reason. While we were connecting to the server, we will give associate service. Whenever we do associate service, it is going to use the port number 22. Okay, assume that if it is a telnet, we can use that telnet. If it is Artist Hatch, we should use this one. Okay? Our dp are deep. You can see double 389 So if you want to connect to the windows server, then you can use the rdp Remote desktop protocol like that. It depends upon the application. You can choose the medium. How do you want to connect At this moment? We have only associate is running on this system. We can connect with the port number 22 under associate only. You cannot use any other service over here Now. If you do remember, we help Telnet command. Right? So tell notified you. You can see here. Tell it is there on? Whenever you execute, totality will go inside to tell that come out from the telnet. You need to just quit on the tell. It is useful to check out whether the particular port is working or not. Let's check that total net. I want to check whether Port number 80 is used in this particular system. Are not Telnet local host. Call on 80. Study Telenet local host to Space 80. You can see here what it is saying. Connecting to the address. Connection refused Whenever it says that connection refusal means there is no service running on port number 80. There is no service running on port number 80 on the local host. Nothing but this system. You have your target system there. You want to check? Then you need to replace the local host with type address again telling it local host instead of local host. I can give my I p address. Also, I will give 22 whether 22 parties used in this system are not. You can see here. It's playing on its connector on. It is saying that associate is running on this particular port member. That is how it is going to useful. That is how it is going to useful under to come out. You just need to get the control. See? Right. So tell it is useful to tell you whether your particular port is used are not on. Also, you can check the same thing by using the net to start minus two. You European command, it will tell you that water it'll ports are used in your system. All right, that's all for this lecture. On the next lecture, we are going to see how can we install your application on a what system? Thanks for watching. See you there 31. L31 - Services - Commands: service [status, start, stop]: Hello, friends. Welcome back in this lecture we are going to talk about services. So what is the service services? Your process. So what exactly service does do this controls that starting and stopping off your service if you install any application. And if you want to stop our start that application services useful for that one under in service, we have one more option. That is GSK country. This controls reaches service are said to to start on board Sometimes what happens? We want to start our services. Well, starting over system itself. Then we can use that chk conflict command. So the services comments. We should execute something like this. Service name off the service status service Name of the service start service. Name of the service. Stop like re Lord restart so we can get these options. Whenever I say status, it will tell you that weather services running or not, if I say starts, it is going to start the service. If I say stop, it is going to stop the salaries. If I say re Lord, it is going to really the con Figuration off your services. Each service how at least one configuration fell it is going to read that configuration for next to restart. It is something like a reload, but Reloaded doesn't close the existing connections. But restart is going toe. Stop the existing connections. Nothing. But if some users are connected, it is going to stop them under its restarted service. Similar were to add our services to started to bow to them. We can use that. See Hitchcock Convict service on to make the service available after restart. Similar way. If we want to bring down our stop the service at the border and then you can execute, CHK can pick service off. And if you want to check a list of the services which are available, then you can use this year's cake config list. Okay, let's try and do this one to experiment. This one. I'm going to install hits TTP application on my server, so it's like a refresh off all over comments. Let's try to do that one. I'm on my Linux system, and I'm under currently route under. I'm your route user off course to install any packages, you must be a road user. Let's try to install your hits TTP yum. Install his study beauty is the commander to install the heads through TV service. Let's execute Onda. Do you want to install it? Yes, I want to install It is going to install all these packages. Alright insulation is successful. As I said, once we install any application we need to start the service. We just to install the heads to DP Service. We haven't started it but if you want to see whether services running or not, you can use service hits to DPD status. Okay, so here hits the DPD is the service name you can see. Here are this moment It is loaded on active inactive status off This one is dead. It is not yet active now to start it, we just need to use service Hates pretty pretty Start on this. Maybe keep on changing. If it is, it's really pretty. You can give a hit 30 Pretty If it is some other process you need to change the process Name? Let's start the service. I just started Only if I check the status. You can see here Currently it is active. Nothing but this particular services running All right. As I said, hedge to DP is going to use port number 80 rate on. Do you want to check which port it is using? Next start minus two. You yelp. Ian, this is what we have seen right in previous lecture grip are I will just to display this one on. Do you see our earlier we were having only port number 22 in listening state. Now Port number 80 also in listening state on which services running on port number 80 You just to see here hits 30 bodies running on DA hits the deportees an application which running on this particular port to port Nothing. But as I discussed initially, it is a locker, right? So now I want to access this locker. Then you cannot go here under do that. What I can say it's UDP hatred. GPU can access it from the browser browser by default to connect under port number 80 So I can access this port number from the Broza. Let me do the I p address off this system. Be to this port number in the browser and we'll see what happens. So this is the I P address. Even I can take the DNs name as well. Let's take the I P address and Colon 80 and by default it report tried to communicate with any services on Port number 80. So you knew not to give this one. Also, it's Friend Butler's tray with the port number 80 and we'll see what happens now. It is trying to connect to the our server Andi, another server. We are running his to DP and Port number 80 on whatever application it is going to give the browser it should display. Of course, it is not loading. I know the problem way because in aws level there is a security group. If you do remember, we helped create area security group right In this secret group, we need to open the port number. So I just to open the new tab here in bone rules don't get confused. All this talk it is like networking level. We are all going to access the port number 80 from the browser. That is the meaning. Heard it and add. I'm giving the hedge to DP. You can see here. Port Number hits two dp for his strategy default Port number is 80. We are allowing it from the Internet. Girardot Girardot Girardot. Jiro. Okay, this is the Internet I p address. Sort of. Yeah, this one. You can connect toe this particular server from anywhere and say this Onda No, I'm goingto stop it under reloaded with port memory 80. Even though you give port number 80 it disappears because by default it runs on port number 80 only I mean to say it's true dp it is going to use And if you try to just to copy it on DA If you paste it anywhere you can see here in front off this one, it's to DP's added heads to DP Nothing but port number 80 and I could able to access the application from the browser. This is how you can install your application on. You can check whether port number is it lays it out. Not on. Also, we can check the same thing by using telnet also right. Tell net local host are I can give die pr yourself forward system. This is the appeared frustrate I P address on the 80. I'm just checking whether port number 80 is used in this system are not are opened in this system are not You can see here in previous lecture. It was throwing an error. This time it could able to connect successfully. I'm giving control. See toe come out. That is how you can run the application only. What? Lennox system and access from the browser. That's all for this lecture in next lecture. We are going to execute other service comments and chk conflict comments on We'll see. How does it work? Thanks for watching. See you there. 32. L32 - Services - commands chkconfig, systemctl: Hello, Prince. Welcome back In this election, we are going to see remaining service comments on also see it country. And if you do remember, we have a deterred our ssh de configuration. Felt some time back. Let's talk about this. Hit the service first. Okay, so what is this message? I'm talking. Shh. From your well, right. So, yes, it's protocol. Also referred as this shake. Your shell is a method for secure remote log in from one computer to another computer. So usually, if you want to connect from one computer to another computer, you can connect securely by using ssh protocol. That is the associate service. It provides the several alternative options for strong authentication on it protects the communication securely on the integrative it strong encryption. So it is quite secure. Way to communicate under it enabled the encryptions as well. So what is the port number? Offices. Shit off course you might know that is port number 22 on the demon is a city on conflagration. Police Last CTC is the shit. Ssh! The underscore conflict friend, This is the default configuration. Similar way for him. Http Port number is 80 under demon name is hits the deputy on the con figuration Phyllis Last CDC hits to the beauty slash cont slash hoekstra t Pretty dark conference if we want to change some default values for hitch. Really pretty. We need to edit this. Well, now we are going to update our hits. Pretty pretty application, and we'll see. How does it work? All right. I'm on my Linux system as a route user. And by default, if you see it is running on port number 80 earned, it is a default place. I don't want to see this default place. I want to change some other page. Then by default, it looks for application filed in the where Dub, dub, dub head. HTM L in this location, it is going to look for the application Are this moment It is empty. That's the reason it is going toe rear the default file now. I want to give some index start html file so v a index dot html I'm creating and ah, just giving hatch one. This is it Hits TML format. Hello. On the clothes hitch one under heads to models here itself. Rebuild right. Hello. Welcome toe Lennox classes. Okay, Just I'm going to save this one. Once you have abducted, they were configuration. You need to restudy. What services? Okay, sometimes even though you don't restart your services, it may pick up. But the best practices you need to stop and start the service are reload the service or restart the salaries. Okay, Service. It's pretty pretty status you can see here. It is still open turning. I can do service. It's really pretty restart. Okay. It is going to stop and start the surgeries and also reload. You can do models, you can do the service. It's pretty pretty storm, then service. It's pretty pretty start. Either way would be fine, but this one stopping and starting the service is going to cause it's always destruction. Nothing. But whenever you stop and start, somebody is accessing. They cannot have access, even restart also create the similar kind of issue. So reload is their best option. But anywhere will go on the refresh our prayers. No, you can see here. Hello. Welcome to early next classes. That is how you can update your configurations. Now assume that I need toe restart my server. I'm going to do the in its six. Now What happened? Sorries don't. Whenever surgeries don't, you cannot access this application. Sorry. You cannot access this application because sorries don't. So there is no access to your application. I will wait until the server comes up on See what happens. I'm just giving our to restore decision. Yes. No, the satellite is up on DA. You try to access my application now again, we'll see what happens. Still, it could not able to access it because my services are not running service hatred. He pretty straight us if we check it is endured. State off course, I need to log in as root user. So, Sodo, this human is to start the service, and you need to start the service service hits pretty pretty start. Okay, so now my services are running, my services are running, and, uh, I can access my application. Okay, so that is how you can do. But you want to start your services by default whenever you're booting your system. That is where chk country comment comes into the picture. So you need to do chk conflict. It's pretty pretty on. Okay. What does it to do? It is going to add the word service to start at the boot time. So all right, we have added to the service to start at the bottom on the let's try to restore the server . I'm restarting. I can use the report also. Okay, So he would also going to restart your system. Onda, Let's go on. Check it out this time you Even though I don't start the services, it automatically should come up off. Very start. I'm just checking with the stories up or not? Yes. No, sir. Worries up on deep regard. Check for the my application. You can see here it is automatically accessible. And if I check my services certainly is hits pretty purely status. Okay, It's starting. That is how you can start. They were services at the bottom. And if you don't need, you can do this. He hits K conflict hipster DPD off. Now it is going to remove to start the services at boot time. Anyway, I should run these comments as a root user. That's way I'm not authenticated. Let me become your route on the execute took command one second. No, it is no more. Start off the boat. All right, so this is how we can use this. She has K country comment on one more command. Is there that this system CDL system City L our service Both arson. Instead of giving service system CDL State State heads to deep relief. Ugo Sorry. There is a typo system CDL status hits two DPT for you. It was going to give the same information. Even you can do the same thing System CTL, Stop history, beauty. You can stop the service and you can check the status again. It is stopped when you can start the series. All the stuff we can. That's how it works. All right, that's all for this lecture on to see in the next video. 33. L33 - Process Management - Commands: ps, fg, bg, top: Hello, friends. Welcome back in this lecture. We are going to see a boat process management first. Let's understand what is process when you start your program are running on application in Lenox. It actually runs. Here's your process. So every were running. Some comments are programs or applications in the background. It treated as the process Yellen X process. Are your demon running in the foreground are in the background? Use memory and CPU resources. So whenever we run, any process it is going to run either in the background are in the foreground 100 condoms. Some memory in CBO's. Now let's see the water noodle Common comments we execute in the process management PS minus year list of the process which are running in the system under kill. If you are running some process and if you want to kill, then you can use the kill on the kill minus nine. Is those sure killed? Then f g. Nothing but foreground. Busy. Nothing but background top. It is going to list of the top 20 process, which are condemning more CPR memory. Let's go and execute this commence. So this is my Linux system and I have logged in as root user Over here. Let's exhibit our first command PS minus year. It is something like equal toe under your task manager. Here we go. Task manager Right here We have all the process right A different process, something you can able to find out from the PS command in our Lennix system. So PS menace. See if you can see so many process are running on your system and each how Your processor t This is Pierre Prosperity One is the parent prosperity for all the process. Okay, this is the apiary. But for Peary there is a jury is there. But just think that appear. The one is the parent process already like this. It will be keep on growing on one process. May depends on another process as well. All right, so this is the process table we can call and even you can find our hits. Pretty pretty service You can see here hatred people eat is running is therefore services. And this is the process for each one on the 1st 1 It is the parent process you can see here . This is the parent prosperity on the process When this is parent prosperity process One started this process on mixto processes started about this process. That's why parent Prosperity's six Double even this one also started about this one like that. It will be there. And if you kill the pasta process, then all the process are going today. It means that you are holding your system. So we never killed this process. Right? So that is how the PS minus C of table works on. But you want to get only hates pretty pretty related information, then ps menace CF grip hits 30 people argue it is going to list or the only hits treaty process on. They want to only get the heii associate. You can see the associate process. All right, so this is how you can find out your process. Next, I want to kill your process. I want to go kill your process. So a gym that you want to stop hits pretty pretty services. So service hitched a pretty stop. You. Can you assume that after exhibiting this one also your services not getting started, then what you can do? You can check out your process and kill that. But before killing, I will just take the Good Saturday states to the beauty status you can see Even here you will have your processor t You can see it. Main processor. You can check it out. 16. 65. I can kill this process Mints. It is going to stop the services. So to kill the process, we have your command killed. You will process ate it. But this is not based away. In worst cases, we are going to use the kill are. If you don't have these kind off services comments to stop your services, then you may go with the deception. But this is not here. Right Where to stop. But still Let's try this one. I helped kill that process. And if I check the status now, you can see here it is inactive state Nothing but we hope killed our services. Right? That is how you can kill again. I'm starting the service and if I check the status now again, it is active. But this time the process already has been changed. Well, because already that process early maybe are compared out. It is in the records for some time. So you are going to get the new process like this. It works now to experimento one more time. I'm going to connect as a John user. If you do remember, we have connected our system as a John user. So let me go here on Connect to Adam's mark. I'm going to connect as a mark user. So Mark User password also Mark. Okay, I have locked room Whenever you locked him, one more processes get added over here about your decision about his station password is not working. Let me reset the mark. Password. Okay. How do you set his password again? I'm going to log in as a mark user. I don't want to remember it. Alright. I have logged in as a mark user on Whenever you locked in, you will see when processor to get creates over here PS menace et a grip market figure. You can see Mark has been logged into the system and this is the time 6 49 And the question that date? No, you can see 6 49 he loved in. Now I want to kill the mark process. If I kill Mark process, he will get out from decision. Nothing. But he logged off from the system so kill minus nine minus nine. Nothing but sure killed water. Where it happens, you need to kill. Okay, so you need to get up. Process city. And this process is running as a mark. You is that right? Okay, so this is the processor unit took you. So let me kill this one. And if I see here, it got to the activator. It got to deactivated. And if I check again no PS minus CF Mark. There is no stations from the mark. I mean to say essence. It's stations from the mark. Okay, so that is how you can use the kill command next next to the F G. Under busy. First of the legs go too busy. So I'm on my Linux system. And by default, if you want to run any process in the background, we can just use something like this. Sleep then aren't symbol so usually fugue. You aren't symbol. Your process is going to run. Are the background So this sleep command What exactly does it Trudeau? You're Constable. Wait 10 seconds over here. There were considerable waited 10 seconds without doing anything. Now, if I execute, you can see here already. 10 seconds are over. But it was running in the background. So you cannot able to see like this. You can run, but sometimes what happens? We may exhibit some Commence on it is taken quite Langdon. You don't want to kill those process. You want to still run those process? Then you can send those as a background process. Let's do that one. So a gym that sleep 500 I'm giving whenever I give sleep by 100. It is going to wait here at least seven minutes. I don't want to wait seven minutes without executing anything or I want to take it off some other activities. Then what you can do? You can just give the control. Jed Control Jerk. Whenever you get control, Jer, this particular process get started on the added to the processed table. You can see here This is the faster job addicts. That's where you got one. Assume that again. I executed sleep 200 and ah, even I thought that Ok, I want toe do some other work. So again I stopped it by using control. Jered, you can see here now. There are two jobs executed for that one. I think you can find out by using the jobs command? Yes. You can see here to jobs are there on? Both are in stopping state. This is the faster job. One is What's the job? This is second job now I want to run this. I don't want to get it stopped. I want to run these in the background than what we can do. We can just to give the BZ but sent days want What does it do? The cross to command it is going to run in the background. Okay, now you can see here it is exhibiting in the background and automatically UN symbol came into this one on again. If I check for my jobs now, it is running in the background. All right. Same thing I want to do for this one as well. Then I can do there BZ percent raisel too. Now you can see here Second job also guard starter on Both are running in the background Now I want to bring these into friend and then I can do you f g person Basil. So if I do FG percentage toe this job, it is going to get into the front end Andi were Carson will be keep on waiting until it completes 200 seconds. That's how you can send your jobs as a background are for grown. Now I'm giving again control, Jered so that it is stopped on the jobs. Let it get executed in the back rooms for that. Again, I'm giving busy person title to That's it. So now both jobs are running. That's how the four grown on the background jobs works. But here I'm using sleep comment. But usually it could be some programs. Right. Let me clear this screen. All right. Next to Top Command, top Command is going to display their top CPU dilated process. You can see here there is a user called the mark with occupying some space way. He is condemning. Is he running? Still process. Okay, maybe some processes running with the mark in the background. Then Apache. We have installed Apache. It's really beauty on a few other services. All those process information it is going to give on. Also, it has a lot off other information. Total number of tasks it is executing, and ah, CPU retaliation User is using 99.3 system how much it is using on the memory. Also ate 16. They're out off that. How much free space and how much used is there? All this information is displayed with the top common. To check out our system performance, we usually use the top command. So that is how you can check the system performance and you can run the four grown on the background jobs. Thanks for watching and see you in the next video. 34. L34 - Archiving files and directories - Commands: gzip, gunzip, zip, unzip, tar: Ha LaFrance. Welcome back in this lecture, we are going to see how can we are care our trial starter directories. For this, we are going to use a few comments. That is gyp gyp under terror Gyp andan jip are going to work on file, but Tatar is going to work on directories first. Urge Egypt. It is going to compress the files. So what is that? One days of compressing over files? Because we can reduce the size off our file so that we can save some space G on Jim. This command is going toe underpay airfoil next to tar it is going to extract tar file are created are for Let's go and see how does it work? I'm on my Lennox server and I have logged in as root user. And if you see there are few files There is already a file with the tar dot g jered, which we heard downloaded it sometime back. But we are going to deal with this file later, Foster, Let's see how Jeezy Punditji injectors work. I'm taking your file called File one on. If you see it has some content on the left. Me clear the screen again on the lily for a check. The file sizes 8 79 K b. Now let's execute judge upon this one. Most of the cases Jesup doesn't come with our operating system. So you need to install by using You were young command. Yum. Install Jay Z. OK, but in our case, I think we have already installed it. If it is already installed, it doesn't do anything. Okay, you can see here. This practice is already installed under nothingto. So this is tripe. Oh, sorry. Now let's execute our jeep Commander Jesup and file whenever Do it is going to create a Jeep file on file one. Only a less menace l If I do, you can see that depend has been created. Instruct file one on the extinction is Jesus earned the size you can see for 75 k b. It's almost reduced the party to 44%. This is how we can do peer file and similar way we can inject this content. You queen, You g on gyp. I'm closing him. Okay, so it is going toe again. Extractive or file name. I will just give. Ellen came back as a ward general file. This is how gz Pernando chip will work and we also help compress. Okay, It works on few operating systems. Under doesn't for conf you let me try to install compress. If it is there, it is going to install. So compress andan compresses there and also gyp under un jeep also is there okay, didn't find this one. Let me drive it to the just a jeep. Sorry, Bridget Triple. Okay, chip is that you can install by using? Yes. Alright, gyp installation is complete. Er on the even. We can execute Agip on this one. Gyp file one. Okay, sorry. We need to give Egypt file one daughter gyp on file one. Which file do you want to gyp on? What is the destination? Fell. Now you can see here it has been compressed on deferred to Ellen. We have orginal fell as well as it created additional gyp file. Okay, I wonder if we want Owen gyp on Jim followed by our file name. You can on gyp. Yes, I want to rename because it is already there. It is asking whether do you want to really? Over Right. All right, now let's see the Tar Command so usually depend on gyp is going to work on files. But if you're tried, toe execute scenting on the powerful it doesn't work. If I do g gyp directory one because directly one is the barrack Reso did saying that. Jesus, the air when is a directory and ignored So it doesn't work on Derrick, please. And if I go inside to the d a r one, you have a few files 100 directories. I have already created a few files under directly Sandip Ray, open file three. You have some content as well. This is the final three. Now I would like toa gyp this well so sorry Egypt, this territory for that one. We are going to use the Tar Command so bad minus cv. If there are multiple options are flags are there. But we usually use tar minus CVS. Here, C stands for creates restraints for war boars. You have stands for file, so we should probably the file name. What do you want to get once it is compressed? So I want to get the air. One daughter Tara, once it is compressed. So this is the destination file name? What do you want to get on also beach directly. Do you want me to argue? So I want to are killed. The air one, They are one Dr Phil. All right, so let's execute on. You can see it is are killed. All these fells once it is are killed. It is going to create yet the air one doctor and you can still see the source. Well, okay, now assume that somebody came under the leader That the air one. So our a minus r f d a r one now Still, I don't need to worry because I have already taken it as a backup. So I can on our carrot toe on archeo I can use that ar minus x three year so x three of nothing but extract their directory. So the extractor file So d a r one doctor Now you can see again. It got extracted under You can see that the air one. And if I go inside, you can see the same file Sunday. Reckless. And if we were open file three, you can still see the content. That is how you can create your careful if you see here. Tar file once we created a powerful It has been con water as they filed It is not your directory anymore. Okay, so that is going to create a fell by taking all the data off their directory. Now you conjugate this fell way because gyp is going to work on files. Right? So you can see the size over here and it is going to reduce Once we did that gyp common. So G gyp undocked File name turned, you can see. No, it has been Reduce it to 2 77 KB. That is how we can use the parent. Gee, Egypt, on the same trail. Even you can see here from Apache. Also, this is a very big on large felt. So with the chip itself, it is occupying almost 10 MB so we can extract this one first. What we can do on gyp g on gyp on the file name, then we can under this one rather than that one. We have your single commander toe do both. That is the r minus. X ray Jeff followed by You were filing him. What did you to do? It is going toe extract the file on. Also, if it is gyp. It is going to engine. That is what Judd Flat does. Do OK, so faster it is going toe on. Jip the file, then under that one, let's execute this one. Now you can see you have your source. Well, as were Leicester. It got creativity, the extractor one. And if I go inside toe this directly, you can see a lot of files. 100 directories. All right, This is how we can use Onda again One more time I'm doing. But this time I'm running as it'll different comments before that, I'm removing this Apache Tomcat file and, uh, now again, I'm doing They are Sorry. First I will do on gyp Just I want to show you the size sort of g ginger gyp. So the gng pit g on gyp It is extracting only a little. If I check, you can see here now. It became almost 15 and be earlier It was only 10 numbers. So that is how we can do. And again we can do Dr. Now there is no extinction off digit rate. The AR minus 63 years now I don't need a jerk because it is not yet geopolitical at this moment under it has been extracted. And if I do it'll you can see the directory. That is how we can use gyp under tar comments. Thanks for watching and see you in the next video. 35. L35 - Crontab: Hello, friends. Welcome back in this lecture we are going to talk about ground up in any operating system. It is possible to create jobs that you want to re occur. This process known as a job scared doing, is usually done by your user. Different jobs for redheads are any other Lennix. This process is handled by the Crown Service Are your demon called Cron which can be used to schedule tasks. So the whole purpose of crown tabbies to schedule you were really occurred. Jobs. Whenever we schedule that job, respect off. Whether we were in front off system are not that job. Get eggs Eagles. That is that one days off. Toronto? No, In contact, we usually use thes two comments that is crunched up menace l and current of minus e. The richest specific format you should follow. Toe created Crown jewel in the crown job. We should specify minutes, hours, day after month, month, day after Vic under command. These six fields are mandatory here. Minutes value all over the years. Gerardo. 59 hours filled. We need to provide Jiro to 23 Jiro. Nothing but midnight toe oclock 23. Nothing but 11 were clock 11 oclock in the night day off the month it is from 1 to 31. There is no change on a month. It is 1 to 12. Next day off. Depict it varies Jiro to six here. Jiro. Nothing but someday. Six. Nothing but Saturday. Next to comment. The job which you want to schedule here we need to provide a that sell script. Our comments. What do we want to execute now? Let's see few examples to know how the contact does work here. If you see the first example, executive a job at 8 30 on everyday monitor. So 38 even weaken, give generate, then every day, morning. It is a very day, so we should not provide that date our day off, the month our day off the week because it should happen everyday. Whenever whispers first start, it equals to the all the numbers which we can give in that particular field. Next executive a job are toe two PM on every Saturday. It is two PM Whenever we said 2 p.m. it is Jiro Jiro under two PM rate. So it is 12 place to so 14 then start started because we want to run it on a very Saturday , so we should not specified this Saturday Minutes six, followed by the command. Next exuded a job are the 12 am unforced Egil eight. It is 12 William So Jiro Jiro, then fast to generate Foster minutes 01 Jill Eijiro six. Then start followed where the command next executive a job are to treat that DPM on every month. 25th. So it is 3:30 p.m. So topped it on the three PM rate. That's way it is 12 plus tree So 15 25th and every month So start in the month field as well as day after Vic, then common. So this is how we can do No Let's look into our landing system and will create few jobs This is my Linux system on dime underst last routed directly. Now I can check out my counter by using Toronto minus so crunchy minus l Nothing. But it is going to listo jobs, which you have created under your account on grant of is available for each user. It is not yet single one which can be available across the system by default. Each user can create their one crown jobs. Currently, I have logged in as root user so I can create Cron jobs as a road user to create a Cron job . We need to execute front of minus e Eastern's for it now File has been opened in the editor mood. Here we can add our crown jobs. Now let's see our examples itself. So frustrating Used executive job art 8 30 on every day Morning. So going in certain more onder 8 30 right? So top tea Jiro it And it is on every day. So all starts under command. I'm just giving you command as echo one double grave The done slash TMP file one. So it is going to create your file under slash TMP and keep the one in that particular field. It is double great of them Nothing, but it will add this value your every day at 8:30 a.m. In the morning. Okay, next to think executive job or 22 pm on every Saturday. So it is two PM raid Jiro Jiro g 14 2 PM Right on every Saturday. So here we should probably Jiro six didn't they're cool to slash TMP file toe. This value should get out of this particular Kyle on every Saturday at 2 p.m. Next thing is executive job. Our total. Yea, am on Frosted. You're late for that 12. Right? So it is a double Jiro on the hostage a late. So here here we need to provide. First July means 06 on the Star Echo three. Great of Done slash TMP Final three Next thing is executive job are to treat 30 p m on every month 25th So it is 3 30 rate so 30 on 15 because it is 3:30 p.m. on every month 25th So it is 25th on every month Earned the Echo four double greater dance last TMP really for okay, I'm just giving you a Kocaman, But usually it can be anything. Usually it can be anything. I'm still this way and grant of minus yearly figure again You can see distant Now we have four crown jobs. All right now we'll executive a job immediately Now If I check date it is 3 14 No, front of minus e l sorry. Count of minus E on. I'm going to skate. Julia job at 3 17 I'm giving 17 Jiro three because it is morning and start. Start, start every day. Morning at 3 17 I want to execute your job. Bqool on slash TMP file fight. If this file doesn't exist, it is going to create. Now we'll see the date. It is 3 15 and I'm going to slash TMP. So far, we don't have any fails. Look, a file one is dead. It is a clear which we have ordered our menace. Olives. Fine. I'm removing all friends. They're less okay. There is no files. Whenever it become 3 17 it should create your file over here. Let's wait. Okay? Nobody 6 50 and still file not yet created. And if I do a list? Yep. Now you can see your file has been created with the file file on before you open this file , you can see number five again tomorrow at the same point of time it is going toe. Add one more time number five, below toe, This one. That's how it works. But if I want to execute your job very minute front of minus e every minute, then I can edit Grant are creating a new job over here by using star star, star, star star. It means that every minute, every hour, every day after month, every month, every week exude this one. So echo six slash TMP 56 Now if I do unless you can see whenever it becomes minute it is going toe added a number to our file six. So far, Pile six is not created under whenever it become 19 minutes destroyed. Get created after that Every minute it is going toe area number. Okay, now you can see File six has been creator. It will be keep on adding for every minute. That's how Cron jobs works. But instead of a Kocaman, usually we use our cell scripts over here. All right there cell for this lecture and see you in the next lecture. 36. L36 Link Files: Hello, friends. Welcome back in this lecture, we are going to talk about link files. There are two types off link felt. One is soft, Link. Another one is hard. Link. This to kind of files helps us to create a the shot. Cut our back up off our oil. Let's see the difference between soft link are hard link. Soft link is like a shot cut file. It is something like another window system. We create a sharp cut on our desktop rate. Same thing it is not going to create a file. It just refers to the original file. Hard link is like a backup file. We can create a copy off our existing friends. So it is like a backup file on the size off. This file is equal to the number of characters in the name of the original file. In this case, we are not creating one more file. It is just your shortcut. It doesn't arc way much space it just to occupy the space home which is required to create a shot card. In this case, it is going toe occupied the equal in space off our virginal file way because it is a kind of back off file. If we don't find his deleted link is broken under. Data is lost. So in soft link. In case if you deleted your original kind, you were softly cannot able to map to the original friends so it doesn't work in hard link . If orginal file is deleted, then also limit will contain data. In this case, it is kind of back up. Even the utility of original pain. There is no issue. Next comment to create a soft link is Ellen Minuses Source. Well, under destination fell very as in hard link commanded. Ellen Source. Well, under destination file here, we don't need to provide any flag. In both cases. If you update the source, will it automatically updates the destination file respect off south clinker? Hardly. No. Let's go on to execute this commenced on our learning system. I'm on my Linux system and I have logged in as a road user. I help few files over here. I'm going toe test this one on file one as well as on file toe. So I'm just walking pile one. You can see the content off File one is Hello. This is filing on a similar way. Five opened file toe the content of file two years. Hello? This is filed. This is the content we help now. I would like to create soft link and hard link on these wells postal. It's created soft cling on file one before creating yourself. Klink, just to check the sides off. You were fined. It is 21 k B. No. Let's create toe create yet softly. We should use Yellen Command Ellen Minuses. File one. This is source. Well, under destination. Well, I'm just mentioning for a living. Now let's execute. And if I do? Ellen, you can see a new file. God, Creator, that is 5 11 And it is mapping toe the file one. Now, if we were open file one are 5 11 content off. These two files are same on if you see the size off 11 it is only five k b. It doesn't operate the extra space. Whatever space is required. Created this way. Only that much space it is going toe con jump. Using soft link, we can reduce the It'll aviation off space in our hard disk. If you need same file in different locations now, If I delete file one, you are going toe lose the date off 5 11 as well. If I check now, you can see here it is in red color and blinking. Nothing. But it could not able to find the original file if I tried toe open 5 11 It is mapping toe the file one. So it is saying that no filer directly exists even though this family's existed is mapping toe the file one. This is the problem into the South Clinton, but it reduced the it place enough space. Now let's experiment with the file to I'm going to create a hard Lincoln file, too. I'm going to name it as their file 22. And if I do? Ellen, you can see here file two years using 21 k B. Andi even filed 22 also using 21 k b. And if I see the content of both the files, it is same. It is seen. And also if we delete a file to it is not going toe do any harm to file 22 way because file 20 to act as the independent file even though you lose file to it still works. This is how hard link works. Now, where do we use this? Soft linger. Hardly. Usually we use soft links, toe create a sharp cuts off our scripts. I'm going to quickly write a script which will help us toe understand this concept more clear. Whenever I say I'm writing script, it wouldn't be much. Lenti. I'm going to ready a single command script. That is eco. Hello, world. So I hope I didn't explainable TECO Command so far, Echo is a command which will help us to display the content off our file. You can, just to see whatever content you have given over here. Same thing it to displace. Now I'm going to create a file that is Hello? Dart s hit. Usually sell scripts were eight in darkest sketch format Under this, I'm just mentioning. Hello Board. Okay, just I'm mentioning this Command on Did save this file. Sorry. Escape. Colon saved this well. And if I open Hello? Doctors hit. You can see just echo. Hello world. Now I need to exclude the cell script. Usually whenever you want to execute any self script, you should do the execution permission under sell script. If I do a little Hello World without shh Currently there is no execution permission on this . Well, so to grant execution permission we can you see Hitch more seven double file So seven Double five Nothing but water is going to get real great execution permission. But the group and other people are going to get rid execution Read execution permissions Now let's execute on defy Do L l again This time it is in green color. Nothing. But it has execution Permission to exude self script. We are going to use darks class You were self script name you can see here. I had just executed my haloed artists Hit it has displayed the output off my shell command That is a co command. So I assume that this is this self script. Now if I want to execute Thistle script from slash TMP I'm going in Saito slash TMP And if they exude hello dot Shh It doesn't work way because you need toe Come over here. I mean to say were you have created this Well I help Creator this well under root home directory So I should go under route And if I do alone here we have. Hello. Dot s yet only I should run from here to execute this crew. But you want to exclude descript across the system wherever you were. You still want to exclude it as a comment? In that case, you need to keep this file under some other execution directories. Exhibition directories, nothing. But if you do reach a less if I do, it tells you that were Israel s command. Is there similar a figure reach. Hello? Dart s search. It says that I could not able to find this command anywhere. Usually checks under all these Derek, please. So if you keep you were hello dot Shh. Pile under any off this location you can execute. Hello, daughters hits from anywhere. So usually we keep our custom commands under slash serious or local bin. So either we can copy this file under this location. Arles. You can create its half clink for this one. How can we create yourself? Cling. Very simple. See, Hitch. Sorry, Yellen. Minuses on Berries over. Hello dot Shh File is there It is under route. Hey, Lord. Artists, henchmen on. Do you must do the full part off. You were script on Where do you want to copy? Are creating a sharp cut for this one. I want to create a sharp cut under slash Serious or local Been on What is the sharp cut name you can give hello dot is hit arrows Just a Hello we can you? So now we helped create area shot cut file under slash usr local bin Now if I gorn display the slash Ryszard local been You can see there is a hello commanders there which is represented a slash root slash Hello dot Shh. Now we figured just to Hello It is going to exude toe other hello dot Shh Command You can see you know earlier whenever a you Hello command It was throwing an error Now it is executing hello world way because we help created Yes shot Cut that whenever somebody exude Hello repertoire this particular file And if I do which hello you can see it is saying that Hello Command is available under us Our local been hello earlier it was throwing in error that no such file or directory This is how we can create link files on Moreover, if you see hello file you can see It starts with yell Yell stands for link will even here also, if you see these yell file so for soft Linky will get yell But for hard link You don't get yelled if you see file 22 the reason oil way because it is kind off back up That is how we can use the link wells Alright there cell for this lecture. Thanks for watching. See you in the next lecture.