Subtitles of the Movie

Alright. Let's go ahead and open up a terminal window. We can right click on our desktop and click open terminal and let's get a typical terminal. Now, at the command prompt you can see, uh, my little hash mark there that we are, uh, logged in as root and this is something you probably don't normally want to do unless you absolutely need to. It'd be better, and we'll talk about, uh, uh, managing the root account later on during the course, it'd be better to log in as yourself and then SU to root and we'll talk about that later as we go. That's similar to using the run as command in Windows. Now, we see a little hash mark there and that indicates we're logged in as root and as root we can basically perform all system configuration actions. Let's take a quick look at a couple of files really quick. We're going to use cat command, which basically just displays a text file. Uh, we need to put the full path in there in the file name itself. Let's look at the SC host file. Now, without going into detail, the SC host file was used, uh, prior to us having DNS servers on the Internet and in small networks where you didn't have a named server and what you would do is enter the host information and IP address in here and it would map the IP address to the host. Uh, these aren't frequently used anymore. They might be used in small networks. Another file we can look at is the, uh, Xinetd.conf file. And it basically controls a lot of your network services. And again, it's a text file and I'm not going to go into depth on how to edit most of these files. You need to do some research if you're going to play around with these. I'll show you a better way to, uh, play around with one of these files here in a moment. SC Xinetd.conf file, as you can see, most of these files have particular, uh, particular uh, uh, similarities. They hash marks indicate comments, of course, and you can put anything in comments that you like. And then there'll be short entries for the actual configuration settings or commands that you need to put in there. And again, if you research these files on the Internet, you can find that they're very easy to edit. Hey, don't get scared of these, especially if you back them up first, of course. Another one we can look at is the init tab file. The init tab file, or, uh, initialization tables sometimes it's called, basically is a file that tells you what the different startup options are for your computer, or run levels. We'll talk about run levels a little bit later in the course, but essentially run levels, if I had to make a, uh, analogy in Windows, it would be the difference between, uh, Windows regular mode and Windows safe mode. In safe mode, of course, you load up with different drivers, limited drivers, limited capabilities and you can perform system configuration options or system rescue options in safe mode. Well, Linux has that as well and they're normally called the run levels. Instead of two different levels, such as safe mode and regular mode, you can have six run levels, uh, in a Linux system and they both do various things. Run levels zero, for example, um, halts the system. Uh, run level six, uh, reboots the system. Uh, run level, uh, one basically is a single-user mode where it, the single user can log in normally root and no other user can log in. You could also have a multi-user run level, but without a GUI, that would run level three and then you could have a run level five, which basically is a, um, the full, multi-user option with a GUI, with the XWindows interface running. Now, keep in mind that that's not all these run levels do. You can have different commands and services start when these run levels are initiated. Ok? And this file, this init tab basically does just that. Essentially it will tell you, in this little section right down here, what the different run levels are and it will call scripts and these scripts are loaded in the various, uh, directories, RC zero, RC one, uh, and so forth and these scripts will basically determine what happens at a given run level. So you can actually customize that fairly well. So I would definitely recommend researching the init tab file if you plan on, uh, messing with this file, uh, at the command line and with a text editor. And again, always backup these files before you, um, mess around with them so you don't accidentally mess up your system. The one thing you can do that's actually pretty useful and I kind of like it, um, is there's a GUI method of editing some of these files or changing options in the files without screwing them up. If you look in the YaST control center, the advanced options of your control center and you look under the system category, there's a sysconfig editor and essentially what the sysconfig editor does, it allows you to edit certain configuration files and certain aspects without messing the, uh, without messing the system up. There's different options here, um, that you can look at and these will directly modify these text files again, without really, without messing anything up; hopefully, very important. Um, you can look at different options such as, uh, the desktop. Now, you might find this entry very difficult to, uh, play with, uh, in a text editor so you could just change this entry right here and it tells you the file that it's going to alter and what the possible values are, what the default value is and basically what it does. There's different, uh, scripts that you can play with using the sysconfig editor. And this includes the desktop, display managers such as configuring GNOME and so forth, your window manager, uh, basically where you would determine whether or not, uh, the default window manager is GNOME or KDE or FEWM or some of the other Windows, uh, desktop environments. But the bottom line is there's different settings you can use to change these text files without directly editing the text file and that's kind of a good thing, especially if you're a novice user. That way you can kind of get some confidence in editing these files without messing anything up. Again, it's still a good idea to backup these files before you play with them. That's essentially a, a small introduction to some of the advanced system configuration options. Once you become a quote unquote Linux guru, you'll probably be spending a lot of time at the command prompt and editing these files directly yourself. But until then, feel comfortable using the GUI because you can do most things with the GUI as well.