WEBVTT 0 00:00.230 --> 00:05.960 Now, the first thing we're going to do is open up Terminal and inside terminal, we're going to navigate 1 00:05.960 --> 00:07.560 to our desktop. 2 00:07.580 --> 00:13.640 So if you're not familiar with the command line and you haven't watched the module on the command line, 3 00:13.640 --> 00:18.260 then I recommend you to take a look at it now because we're going to be using a lot of the commands 4 00:18.260 --> 00:20.480 to create directories and navigate around. 5 00:20.480 --> 00:24.710 So if you're not yet familiar, then it's a good time to take a look at that. 6 00:25.660 --> 00:33.490 The first thing I'm going to do is I'm going to cd into my desktop, and here I'm going to create a new 7 00:33.490 --> 00:35.560 directory called Story. 8 00:36.580 --> 00:41.020 Then I'm going to cd into this Story directory. 9 00:41.020 --> 00:45.010 And if I show you with ls, you can see that it's completely empty. 10 00:45.010 --> 00:49.030 And similarly, inside Finder, I can show you the same thing. 11 00:49.300 --> 00:53.020 Let's go ahead and create some text files. 12 00:53.020 --> 00:59.590 I'm going to use, touch, to create a file called chapter1.txt, and then I'm going to open 13 00:59.590 --> 01:00.790 chapter1.txt 14 01:03.430 --> 01:09.040 So let's go ahead and open chapter1 and let's write something inside, shall we? 15 01:12.650 --> 01:15.000 Okay, so there's my masterpiece done. 16 01:15.020 --> 01:17.930 I'm going to go ahead and hit Save and I'm going to quit. 17 01:19.080 --> 01:22.590 So that was our first chapter, done. 18 01:22.620 --> 01:30.300 Now let's create a Git local repository and start tracking some of these file changes. 19 01:30.330 --> 01:34.290 To initialize git we simply write "git init". 20 01:34.890 --> 01:41.070 And as you can see, it's initialized an empty git repository inside the Story directory. 21 01:41.100 --> 01:45.840 Now if you have a look inside finder you actually can't see this dot git at all. 22 01:45.870 --> 01:52.830 But as we learned before, if you use, ls -a, you can see all the hidden files and you can see that .git 23 01:52.860 --> 01:59.880 is right there and it's going to be used to track all your changes, to commit your changes and to perform 24 01:59.880 --> 02:00.990 version control. 25 02:00.990 --> 02:06.780 So we're currently inside the Story directory and you can also call this the Working directory. 26 02:06.780 --> 02:12.630 So as I mentioned before, using Git and learning about version control, it comes with some of its 27 02:12.630 --> 02:15.170 own terminology and language. 28 02:15.180 --> 02:19.930 So I'm going to try and simplify a lot of these terms that you'll come across just so that we can all 29 02:19.930 --> 02:23.560 be on the same page and we all understand what's going on. 30 02:23.950 --> 02:29.350 Currently, we are inside the working directory, which is the Story directory, 31 02:29.350 --> 02:37.450 and here, in order to start tracking the changes of my files, for example, chapter1.txt, 32 02:37.480 --> 02:46.630 then I need to add this file to what's called a Staging Area. And that is basically an intermediate 33 02:46.630 --> 02:53.770 place where you can pick and choose which files inside your working directory that you want to commit. 34 02:53.800 --> 03:00.940 So to see what's currently inside your staging area, you can use the "git status" command, and it shows 35 03:00.940 --> 03:04.960 you that there are untracked files which will be shown in red. 36 03:04.960 --> 03:11.020 And this is something that's simply inside your working directory, but it's not yet in the staging 37 03:11.020 --> 03:18.310 Area. In order to add it to the staging area and to start tracking changes in it, then we have to use 38 03:18.310 --> 03:20.530 the command, "git add". 39 03:20.980 --> 03:24.520 We're going to type, git add, and we're going to type the file name, 40 03:24.520 --> 03:27.310 so in this case it's chapter 1.txt. 41 03:27.310 --> 03:29.200 So go ahead and hit Enter. 42 03:29.200 --> 03:35.800 And then if we try using "git status" again, you can see that that file has been added as a new file 43 03:35.800 --> 03:37.360 and it is now green. 44 03:37.360 --> 03:41.890 So this is now in the staging area and it's ready to be committed. 45 03:41.890 --> 03:45.610 So let's go ahead and commit this under version control. 46 03:45.610 --> 03:53.800 So the command is "git commit" and I'm going to use the "-m" flag to add a commit message. 47 03:53.890 --> 03:56.770 The commit message is really, really important. 48 03:56.770 --> 04:03.370 It's something that helps you keep track of what changes you have made in each commit. 49 04:03.370 --> 04:11.650 So when you create a new save point, you want to be as explicit as possible about what changes were 50 04:11.650 --> 04:15.220 made between the last save point and this current save point. 51 04:15.250 --> 04:22.950 For our initial commit, we can use something very simple like, "Initial commit," and this shows that 52 04:22.950 --> 04:24.600 this is our starting point. 53 04:24.630 --> 04:30.690 Alternatively, if you want to be slightly more specific, because in our case we've actually completed 54 04:30.690 --> 04:34.770 chapter1, so you can write, "Complete chapter 1". 55 04:35.610 --> 04:41.280 Now, the thing that you'll realize is that usually with commit messages, they are written in the present 56 04:41.280 --> 04:43.260 tense and this is the best practice. 57 04:43.260 --> 04:49.950 So whereas it would probably make more sense, I guess, at least in my head anyways, to write completed 58 04:49.950 --> 04:56.820 chapter1 as this save point, it's actually by convention that you should always use the present 59 04:56.850 --> 04:57.240 tense. 60 04:57.240 --> 04:59.580 So it's like you're submitting your changes now. 61 04:59.580 --> 05:07.230 Let's go ahead and hit Enter to make our first commit and you can see what commits you have made 62 05:07.230 --> 05:10.200 by using the, "git log" command. 63 05:10.410 --> 05:15.870 You can see that this commit was made at this time by this person. 64 05:15.870 --> 05:18.480 And it also has a hash, 65 05:18.480 --> 05:23.500 and this hash uniquely identifies this particular commit. 66 05:23.500 --> 05:29.530 And then right at the end, you see this commit message of what this save point was all about. 67 05:30.220 --> 05:34.930 So now I'm going to go ahead and create two more chapters. 68 05:34.930 --> 05:45.880 So let's just create a chapter2.txt and chapter3.txt. 69 05:45.880 --> 05:52.240 And now we have three chapters and I'm going to go in and change some of these text files. 70 05:52.240 --> 05:53.860 So let's say. 71 06:05.520 --> 06:08.010 Okay, so that's chapter2 done. 72 06:08.010 --> 06:13.650 And finally, let's go ahead and just open chapter3 and edit that as well. 73 06:25.390 --> 06:25.780 All right. 74 06:25.780 --> 06:27.970 So all three files have been changed. 75 06:27.970 --> 06:33.340 And over here in Finder, you can actually get a quick peek at what the contents are, which is going 76 06:33.340 --> 06:38.830 to be really useful for me to be able to demonstrate to you what Git is doing behind the background. 77 06:38.830 --> 06:45.160 So now let's go ahead and add these two new files to our staging area. 78 06:45.160 --> 06:52.000 So again, if we use "git status", you can see that there's two files that are untracked, which are 79 06:52.000 --> 06:56.320 only in the working directory and not yet inside the staging area. 80 06:56.320 --> 07:02.950 So we can put it into the staging area by simply adding each of them as we did before, 81 07:02.980 --> 07:09.610 git add, and writing something like chapter2.txt and then doing, git add, chapte3.txt. 82 07:09.700 --> 07:16.060 But as you can imagine, if you have quite a few files, then it can get incredibly tedious having to 83 07:16.060 --> 07:17.710 do this one by one. 84 07:17.710 --> 07:20.110 So of course there is a better way. 85 07:20.260 --> 07:26.060 Instead of adding these files one by one, we can actually simply just say, "git add .", and then use the 86 07:26.090 --> 07:31.070 dot (.) to specify everything inside this current directory. 87 07:31.070 --> 07:33.980 So everything inside the story directory. 88 07:34.070 --> 07:40.220 Now if I go ahead and hit enter and then let's go to, git status again, you can see that there's two 89 07:40.220 --> 07:47.540 new files that have been added to the staging area and now we're going to commit those two files to 90 07:47.540 --> 07:50.540 a new commit to a new save point. 91 07:50.540 --> 07:52.460 And you know what to do. 92 07:52.460 --> 07:55.520 If you're following along with me, go ahead and give it a go. 93 07:59.310 --> 07:59.700 All right. 94 07:59.700 --> 08:01.080 So how was that? 95 08:01.200 --> 08:09.570 If you remember, the command is, git commit, and we're going to use the, -m flag, to specify a commit message 96 08:09.570 --> 08:14.940 and we're going to write a message that is in the present tense. 97 08:14.940 --> 08:20.910 So let's say complete chapter 2 and 3. 98 08:21.940 --> 08:28.730 So that's everything I've done between the initial commit and this commit, 99 08:28.750 --> 08:33.200 the only difference is the fact that I've completed now chapter 2 and chapter 3. 100 08:33.220 --> 08:36.100 So let's go ahead and hit Enter. 101 08:36.760 --> 08:39.460 Again, let's check it out using, "git log". 102 08:39.460 --> 08:46.630 We can see that we now have two commits, both with different hashes because they are unique and they 103 08:46.630 --> 08:47.470 are different. 104 08:47.500 --> 08:52.930 The initial one was Complete chapter 1 and it was done at this time. 105 08:52.930 --> 08:59.590 And then later on, about five minutes later, I completed chapter 2 and 3 and that was the second 106 08:59.590 --> 09:00.370 commit. 107 09:00.370 --> 09:03.430 And this is where we are at right now. 108 09:03.430 --> 09:10.730 So you can see by this word "HEAD", this is the position or the current state that we are in. 109 09:10.750 --> 09:14.200 So I just want to quickly recap what we've just done. 110 09:14.230 --> 09:19.480 We created a file in our working directory inside our story directory. 111 09:19.480 --> 09:27.140 So the working directory is the folder or the directory where you initialize your git repository. 112 09:27.140 --> 09:31.550 When we said "git init," we did that inside the Story directory. 113 09:31.550 --> 09:37.850 So that becomes our working directory and from now on Git is going to try and track the changes that 114 09:37.850 --> 09:43.160 it sees between the working directory and the local repository. 115 09:43.790 --> 09:52.460 In the beginning, we created a file inside our working directory inside story and then we used, git add, 116 09:52.490 --> 09:54.800 to push it to the staging area. 117 09:54.830 --> 10:00.410 Now the reason why there is this intermediate staging area because you might wonder why not just go 118 10:00.410 --> 10:03.010 from the working directory straight to the repository? 119 10:03.020 --> 10:05.240 Why do we need this extra step? 120 10:05.270 --> 10:12.890 Well, sometimes you might not want to add all of your files to be tracked or all of your files to be 121 10:12.890 --> 10:13.820 committed. 122 10:13.820 --> 10:19.640 So the staging area is a good place to try and figure out what are the things that you want Git to ignore 123 10:19.640 --> 10:23.150 and, what are the things that you want to be tracked? Once 124 10:23.150 --> 10:29.210 we've used, "git add", we've put our file into the staging area and we're happy with the changes that 125 10:29.210 --> 10:30.530 we are going to commit. 126 10:30.530 --> 10:36.500 Then the next step is to go ahead and commit it using the "git commit" command. 127 10:36.740 --> 10:45.410 So now our file is inside our local repository and that version is given a name through the commit message. 128 10:45.410 --> 10:53.450 So that means that even if we've messed up our file, we can still use the last version that's under 129 10:53.450 --> 11:01.550 version control and we can use a special command called, "git checkout", to revert back or roll back to 130 11:01.550 --> 11:04.640 the last position in our local repository. 131 11:04.850 --> 11:10.130 Let me show you what that looks like in the command line and how we would do that in practice. 132 11:10.250 --> 11:15.350 At the moment I've got three nicely written chapters and I have a feeling that my book is going to be 133 11:15.350 --> 11:16.190 a big seller. 134 11:16.220 --> 11:24.200 Now let's say that I have, you know, been working on chapter3 and I have completely messed everything 135 11:24.200 --> 11:24.560 up. 136 11:24.560 --> 11:31.010 I'm just, you know, fell asleep on my keyboard and I happen to have saved my file. 137 11:31.010 --> 11:35.240 And now if you have a look at it, it's now just mumbo jumbo. 138 11:35.240 --> 11:37.490 And I've ruined my masterpiece. 139 11:37.490 --> 11:45.670 But fear not, because we have version control and we have Git enabled so we have nothing to worry about. 140 11:45.680 --> 11:51.130 I can actually revert the changes that I've made locally in my working directory. 141 11:51.140 --> 11:57.230 So at this point, you can use "git status" to see that we have modifications in our chapter3.txt 142 11:57.230 --> 12:02.150 file that have not yet been committed or added to the staging area. 143 12:02.150 --> 12:08.450 So if we wanted to, we can actually revert this back to its previous glory. 144 12:08.540 --> 12:15.500 But before we do that, we can use a Git command to check out what are the differences between the current 145 12:15.500 --> 12:20.510 version of chapter 3 and the last save point in our Git repository? 146 12:20.780 --> 12:24.140 To do that, you can use the command, "git diff". 147 12:24.140 --> 12:29.060 So the difference, and we'll give it the chapter 3file name. 148 12:29.060 --> 12:33.830 And if you hit Enter, you can see that this is the part that was deleted, 149 12:33.830 --> 12:40.520 so the part in red, and then this was the part that was added, which is our gobbledygook. 150 12:40.520 --> 12:46.400 So now if I've looked at these differences, it might just be that, you know, there's only a few mistakes 151 12:46.400 --> 12:52.460 in my new version of chapter3, and I just want to maybe copy some things over or have a look at 152 12:52.460 --> 12:57.830 how I did certain things previously, and change my current file. 153 12:57.830 --> 13:04.250 But other times it might be that, you know, it's just you want to torch the new file, you just don't 154 13:04.250 --> 13:05.510 want anything to do with it 155 13:05.510 --> 13:09.080 and you would much rather roll back to the previous version. 156 13:09.080 --> 13:15.530 So if you want to do that, then there is a command called, "git checkout" that is going to be really, 157 13:15.530 --> 13:16.910 really useful for you. 158 13:16.910 --> 13:21.020 So, git checkout, and then we're going to specify the name 159 13:21.140 --> 13:24.950 of the file that we want to check out, which is chapter3.txt. 160 13:24.950 --> 13:31.190 And if you just watch over here, which is the preview of the current version of chapter3.txt, 161 13:31.220 --> 13:39.350 once I hit Enter on this command that basically asks to roll back this chapter three to the last version 162 13:39.350 --> 13:42.610 that was committed in our local repository. 163 13:42.620 --> 13:46.070 So if I hit Enter, you can see that almost immediately 164 13:46.070 --> 13:53.270 my chapter3 has been restored to its previous glorious state, and this is the version of chapter3 165 13:53.270 --> 13:57.290 at the last checkpoint at which I committed it. 166 13:57.290 --> 14:01.670 So that was this one, which is completed chapter 2 and 3. 167 14:01.700 --> 14:07.310 Whereas in this lesson we've looked mostly at local implementations of Git, 168 14:07.310 --> 14:11.200 so saving these versions on our computer locally, 169 14:11.210 --> 14:17.000 in the next lesson, I'm going to talk about GitHub and creating remote repositories. 170 14:17.000 --> 14:18.320 So I'll see you there.