CIS Linux

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• Slides

Video Script

Welcome back everyone. In this video, I’m going to talk a little bit about how we can get connected to the CS Linux server. So when we’re working with our webpages, we can actually open up our web page just fine in our local web browser if you’re working on your computer. For this class, we’re going to be hosting our web pages on CS Linux, so we can actually access them throughout the web. Because if we’re just working on our local machines, we’re not going to be able to access that website from anywhere else in the world. In order to achieve this, we’re going to need a tool that allows us to use SSH. The easiest way for Windows is to download something like PuTTY so PuTTY.org, or MobaXterm. If you decide to download or use PuTTY, you’ll be taken to a website once you actually click the download link on their main page to something that looks like this. Now, the file that you’ll actually need, you can kind of ignore all the alternative binary files down here, all you need is the MSI Windows Installer and pick if you’re using a 32 bit machine or 64 bit machine. Most people are going to be using the 64 bit machine. So that’s how you can download PuTTY. If you do a quick Google search for MobaXterm, you’ll actually find the download for that as well. Both of these are 100% free; although, MobaXterm does have a pro version, which essentially allows you to save more connections than the standard version. But for most people, the standard free version will be just fine. If you’re actually a CS major, I encourage you to download and install MobaXterm over PuTTY, because it can actually be a lot more useful and flexible for you in the future for other classes. But PuTTY will work just fine for those as well.

When you actually download and install PuTTY, it’s a pretty basic application. To connect to the Linux server, all you need is the hostname the port and then your Computer Science username and password. You should have already requested and received your CS account by now, but if you haven’t, you can go to selfserve.cs ksu.edu, or you can find that link from our CS homepage and request one. If you happen to forgot your password, or if you try to incorrectly log into your account three times in a row, you will get locked out and your password will be required to be reset. You can do that at password.cs ksu.edu. Once we have all that in place, what you’ll want to do is enter the hostname so linux.cs.ksu.edu into the hostname location and Port 22 for the port, and then click Open. Now, you can also save this connection. So if you type in a name for this, I use CS Linux as my name. So if you type in CS, Linux underneath the saved sessions section there and click Save. You can load this for future sessions that you may actually use this for. For example, like your homework or any other time you might want to connect to CS Linux.

When you click open for the first time, you might see a security alert that looks something like this. Really what this is doing is it’s confirming that you know the server that you’re actually connecting to. And in our case, we know who we’re connecting to so you can just click Yes to actually jump through this particular screen. But that should take you to a screen that looks something like this, where you have a terminal window open for you on CS Linux. Now most of you will either be connected to Cougar or Viper. There are two Linux servers here, both are going to work identical. And even if you’ve connected to Cougar in the past, but you’re now connected to Viper, all of your files should be there just the same. A little helpbit too when you’re trying to actually connect using PuTTY or even MobaXterm. If you are typing in your password and your username into the prompts as you are getting connected through SSH, you won’t see your password being typed. So as you type typically like any a login form, you’ll see like little dots pop up for each character you type. You will not see those here. So if you’re typing and you’re worried that your your typing isn’t actually working- it is. You’re just going to have to be very careful when you enter your password. And that’s also why I listed the password reset website up here, just in case you get locked out of your account.

Now, for Mac users to connect to CS Linux, it’s pretty much the same process but you don’t actually have to install anything. So on Mac or Linux, please open up a terminal window. On Mac, you can find this underneath your applications and utilities. Once you have that terminal window open, all you’re going to need to do is type in this command here, SSH, and then space, then whatever your eID is. You don’t need an actual underscore there. So in my case, my username or my eID is weeser, than the at symbol linux.cs.ksu.edu, which is the domain name, or the address for the Linux server. eID@linux.cs ksu.edu. What that is telling the SSH command here is your username for this particular server that you’re connecting to. And again, the same thing applies here. When you’re typing into the terminal with your password, you’re not going to see your password being typed. So just make sure you’re very careful when entering the password. And again, if you enter your password incorrectly more than three times in a row, you will be required to reset your password at password.cs ksu.edu. Now that you’re logged in, we can actually start doing a little bit of work in Linux. My screen here looks a little bit different than what yours probably does, because I’m actually using PowerShell in this case. If you’re using PuTTY, or MobaXterm, your screen is probably black. Same thing with you are using Mac or Linux. If you’re using MobaXterm, though, you can actually modify the background color and text color and things like that if you’d like. Before we get rolling in with the HTML stuff, we need to actually be a little bit more confident on how we can actually navigate through Linux.

Now we’ve used some of these commands in the class before, like cd, which is change directory. But to know where we’re actually currently at, we’re going to use the command pwd. pwd stands for present working directory, which allows us to see where we’re currently at. So I am now in home/w/wieser, which is my default user directory. Now we’ve used like I said cd we’ve used that before. So cd can be used to change directory. Now a couple handy commands here for that is cd ~. cd ~ will take you back to your home directory on CS Linux. Otherwise, you can do cd and then the name of the directory or path that you want to actually switch to. ls is going to show us the stuff in our current directory. If you also type ls -l that will show it in list form, which you’ll actually see on the left hand side here, the folder permissions or file permissions here, the user that this belongs to, the group that this belongs to, and then the last day modified here, and then the name of the file or folder. The folder that we’re actually going to be working with primarily today is the public HTML folder. But we’ll talk about that here in a little bit.

Other handy commands that we might want to utilize here is going to be the move command. So mv. So it’ll be mv, and then space, the thing that you’re moving, space, the destination where you’re moving it to. You may not have to actually use this command for this class. But it is useful to actually be aware of. cp is copy command works very similar to the move command, but copies the file instead of moving it around. cp works in a very similar way as move where you takes the source and the destination. But this just simply copies the file. rm removes the file. Now, I will put a disclaimer here with rm. rm can be very detrimental to you if you don’t know what you’re doing. So be careful when you’re using rm in any Linux environment. Specifically, if you do rm star, which is basically going to remove everything in the current directory, rm -r is recursive, so it’ll actually go in to subdirectories as well. So just be careful with rm because you can accidentally delete more than you bargained for. And there is no Recycle Bin in Linux. So once it’s gone, it’s gone. So be very careful with the remove command. Cat will just simply output the contents of a file to the terminal itself. And so that can be very useful just to kind of peek at what is in a particular file.

Editing files on a terminal environment is pretty straightforward. What I’m going to showcase here is nano, which is the most basic command line text editor that we have in Linux. Let’s go ahead and do this in our terminal window here. If you want to just clear your screen, by the way, if you just have a bunch of stuff on there, you can type clear and everything goes away. You can just scroll back up, and all of that reappears though, so it doesn’t really delete anything from your screen, it just moves the scroll bar. Likewise, if you press the up arrow or down arrow, you can actually scroll through the commands that you’ve had previously. So what I want to do here is cd into my public HTML directory. Now I did list a command down there, it says mkdir public HTML, you should not actually have to do that command. But if your public HTML folder happens to get deleted or is not there, that is the command you want us to actually make it. So once you’re in your public HTML directory, you can type in nano index.html. Once you have typed nano index.html, press enter, and you should get a screen that looks something like this. So this is our basic text editor here. And all the commands down here at the bottom are what you can use to actually write out anything, save it, cut, replace, that sort of thing. So some of the basic stuff that you would do with a normal text editor you can do here. So to save contents of our actual file, here, we’re going to use the write out command. Now the write out command can be done by holding the Ctrl key and the O key. So once you press Ctrl O, it will actually prompt you for a file name. And since we already typed out the file name, when we when we said nano, we don’t want to change it or we don’t need to change it here. And then all we need to do here is press enter, and it says wrote zero lines. Well because I haven’t really typed anything yet. But that’s okay. If we press Ctrl X as well here, we will actually cause our program to exit. And so that is the basics of nano here. So we have our new index.html file. We can actually load it up using nano so typing nano, and then the file name. Also, by the way, handy dandy little bit of information when you’re working with Linux, or any terminal by the way, or most terminals. If you start typing the thing that you’re looking for, and you press tab, it will generally autocomplete that for you. So makes things a lot easier to use.

But let’s take a look at a another option for us to actually be able to load our webpage on to the Linux server. It is actually really useful for you to be able to use nano and be comfortable with using a command line text editor because sometimes you’ll find yourself on a server that has no interface and it has no graphical capabilities of being able to open up interface that you can actually click through and make edits to a file. So things like nano or even vim which is a more advanced version of that is very useful to be comfortable with if you ever find yourself working on a server like Linux. But if you’re using PuTTY to connect to CS Linux, what I’ll want you to do is also download a program called FileZilla. FileZilla is a secure File Transfer Protocol software that we can use to actually transfer files from our local computer to CS Linux, or vice versa. And so the free version here is just fine for what our purposes are going to be doing here. So save that out. So I will say that when you install FileZilla, it’s going to prompt you to install additional software. That’s why it’s a free software. So make sure you don’t blindly click through the installation because you’ll install some extra stuff on your computer otherwise. If you’re a Windows user, or using MobaXterm, you don’t need to download FileZilla because you can actually use MobaXterm to copy your files over directly. Over here you can kind of see the directory that I did ls on, although you can actually kind of see all the hidden folders now. But here is my public-html folder that I had before that we just created. So once you have FileZilla downloaded, I just wanted to kind of show you the click through for the installation process here. So click I Agree through the agreement. Anyone on the computer that’s just fine, you can add a desktop icon if you would like to. Click Next, choose the install location. Next. And here is if you wanted to actually add the shortcuts here, click Next again. Now here, I think it cycles through different pieces of software, you’ll want to decline this. So don’t install McAfee here. Don’t install this stuff, you don’t need it. So just decline your way through those. But the installation is actually really quick and straightforward.

And once you have it installed, it’ll look something like this. We’re going to connect to CS Linux very similar to what we did with PuTTY. All you’ll need to do is click new site here. And this is going to be for Mac, Linux, and Windows here. So FileZilla works on all of them. I’m going to call this CS Linux again. The host, I want linux.cs.ksu.edu. So the same host that we had before, same port number. But instead of doing FTP, here, we want SFTP. So Secure File Transfer Protocol. So it’s FTP. But the connection is used done using SSH, so it’s encrypted. I am going to go ahead and let it ask for my password here. But I am going to type in my username. You can also change the background color if you want. But then I’m just going to click ok there. So now that has been saved. So if I go up here and click the little triple dots, next to the little server button that I had clicked, and then click on CS Linux. If we type in our password, then now we are connected to CS Linux. And again here, if you try your password, and you don’t connect, and you fail three times in a row, you’re going to have to reset your password. So once you’ve connected, you will see your files here on the left from your personal computer and the files on the right from CS Linux, I’ve gone ahead and made a 115 folder for us to work out of for this particular video, I would encourage you to do the same and make things a little bit easier to work out of. And on the right hand side, I’m going to open up the public-html directory over here on the right hand side where my CS Linux files are. And I can just drag that over from the right to the left, and it will complete the transfer.

Now I can do the same thing and transfer it back to the right. If I wanted to make edits to index.html, and then copy it back over to the server, I could do that. And then what you’ll want to do here is just overwrite and just kind of depends on what the files done, it’ll tell you a little bit of information about what the file is and what the transfer is. But I typically just say overwrite and then I usually just check the always use this action makes things easier, you don’t have to click through as much. Now that we’ve got our basic file, copy over in CS Linux, we can actually try to go and visit our website as well. Now, the website or the URL that you want to go to is people.cs ksu.edu/~ and then whatever your eID is. So for example, mine can be accessed at people.cs ksu.edu/~weeser. If you’ve been following along with exactly what I’ve been doing so far, you should come up to a completely blank webpage because we haven’t really done anything yet. In our index.html file, which is typically the default homepage file for HTML, doesn’t even have any HTML inside of it yet, but we’ll get there in just a moment. If you’re having any issues getting your web page to be displayed, please contact me or one of the TAs or post in the Microsoft Teams help channels and we can help you out as soon as we can. Other kind of issues that you might actually encounter here is any issues with your folder permissions. So if your public-html directory was not there and you had to make it, you might have some file permission issues there. You might have also accidentally named index.html incorrectly, or you might not have put it in the public-html folder. But if none of this actually fixes your issue here, like I said, please contact us. And if we’re not able to help you fix it, you can actually look at the support pages. If you go to support.cs ksu.edu, you can actually find some help pages that our internal IT department has made to help students get your initial web page started up. These should be all of the tools that we’ll need when we start typing in some HTML for our basic webpage.