1 00:00:00,000 --> 00:00:04,408 [MUSIC] 2 00:00:04,408 --> 00:00:08,754 Let us now explore some basic Git commands that are very useful for 3 00:00:08,754 --> 00:00:10,660 us in this specialization. 4 00:00:11,670 --> 00:00:15,760 There's a lot more to get than what we cover in this exercise. 5 00:00:18,167 --> 00:00:23,407 To get started go to a convenient location on your computer and 6 00:00:23,407 --> 00:00:26,745 then create a folder named git-test. 7 00:00:30,340 --> 00:00:34,600 Then, open this folder in your favorite editor. 8 00:00:38,190 --> 00:00:43,170 Here, I have the git-test folder that we just created open 9 00:00:43,170 --> 00:00:45,390 in my VIsual Studio code. 10 00:00:45,390 --> 00:00:49,257 Let me add a file to this 11 00:00:49,257 --> 00:00:54,148 folder named index.html. 12 00:00:54,148 --> 00:00:59,990 Now you can see that I have added in some HTML code into this index toward HTML5. 13 00:00:59,990 --> 00:01:02,580 Let's save the changes. 14 00:01:02,580 --> 00:01:05,240 Now let's switch to our command line. 15 00:01:06,740 --> 00:01:11,320 At the command line, go to the git-test folder and 16 00:01:11,320 --> 00:01:15,860 let's initialize this folder to be a git repository. 17 00:01:15,860 --> 00:01:19,800 So to do that, at the command line, type git init. 18 00:01:21,620 --> 00:01:26,020 Now this folder has been initialized to be a git repository. 19 00:01:27,170 --> 00:01:32,650 This is our first git command that we have learned, git init. 20 00:01:32,650 --> 00:01:36,320 This intializes the current folder as a git repository and 21 00:01:36,320 --> 00:01:42,380 when it initializes the folder, it will mark that folder as a master. 22 00:01:42,380 --> 00:01:45,690 This is the master branch for my git. 23 00:01:45,690 --> 00:01:48,210 Now let's not worry about branches and so on. 24 00:01:48,210 --> 00:01:51,000 We will not deal with that in this course. 25 00:01:51,000 --> 00:01:56,240 We will only be working with the master branch in this particular specialization. 26 00:01:56,240 --> 00:01:58,500 So this would be marked as a master. 27 00:01:58,500 --> 00:02:02,060 Now this is the initial point of our repository. 28 00:02:03,770 --> 00:02:08,410 The next command that we're going to look at is git status. 29 00:02:08,410 --> 00:02:10,510 If you type git status in the command line, 30 00:02:10,510 --> 00:02:13,740 it'll tell you the current status of the folder. 31 00:02:13,740 --> 00:02:17,460 So let's do that at the command line and see what it shows. 32 00:02:19,470 --> 00:02:23,395 At the command line, type git status and 33 00:02:23,395 --> 00:02:28,945 read the information that is tracked out on the command window. 34 00:02:28,945 --> 00:02:31,235 You see that it says on branch master. 35 00:02:31,235 --> 00:02:35,200 So, that is the master branch that we are on and it says, 36 00:02:35,200 --> 00:02:40,690 untracked files, and then shows index.html in red. 37 00:02:40,690 --> 00:02:43,790 On your specific computer, it may be using different colors or 38 00:02:43,790 --> 00:02:49,040 represent this differently, but this is what it shows in my Mac. 39 00:02:49,040 --> 00:02:53,775 So now, this index.html file that we have just created in this folder 40 00:02:53,775 --> 00:02:58,100 is now not been added to our git repository. 41 00:02:58,100 --> 00:03:01,680 So let's go ahead and add that file to the git repository. 42 00:03:01,680 --> 00:03:06,740 So to do that we say git add and you can simply say 43 00:03:06,740 --> 00:03:12,350 dot which means that all the files in the current directory will be added to 44 00:03:12,350 --> 00:03:17,680 what is called the staging area of my git repository. 45 00:03:17,680 --> 00:03:21,740 So now if I again type git status, 46 00:03:21,740 --> 00:03:27,780 you will see that the file index.html is marked in green. 47 00:03:27,780 --> 00:03:35,130 And it says changes to be committed there, and then shows the filename. 48 00:03:35,130 --> 00:03:39,000 And then, so that means that this file is ready to be committed to my 49 00:03:39,000 --> 00:03:39,830 git repository. 50 00:03:41,700 --> 00:03:46,100 So the next command that we saw was git add, 51 00:03:46,100 --> 00:03:51,190 by using git add you can add file or folders to that staging area. 52 00:03:51,190 --> 00:03:57,250 So once you add it to the staging area, then you can commit that snapshot 53 00:03:57,250 --> 00:04:03,100 of our folder status to our git repository. 54 00:04:03,100 --> 00:04:06,460 So that means that when you do that git commit. 55 00:04:08,130 --> 00:04:12,610 What this command will do is commit the current 56 00:04:12,610 --> 00:04:17,200 state of our folders into our git repository. 57 00:04:17,200 --> 00:04:20,380 So all the files, as they exist at the moment, 58 00:04:20,380 --> 00:04:24,570 once they have been stages using the git add, then they will be committed to 59 00:04:24,570 --> 00:04:29,510 our git repository when we execute the git command folder. 60 00:04:29,510 --> 00:04:34,650 So on this point, when we execute the git command, then our initial 61 00:04:34,650 --> 00:04:40,750 state will now be changed to the first commit to the git repository. 62 00:04:40,750 --> 00:04:42,650 So let's go ahead and do that. 63 00:04:45,470 --> 00:04:49,460 Back at the command prompt, let's type, 64 00:04:49,460 --> 00:04:54,880 git commit and then we can ever add a message to our commit. 65 00:04:54,880 --> 00:05:00,520 So I am going to say git commit -m first commit, 66 00:05:00,520 --> 00:05:04,160 because this is our first commit to our git repository. 67 00:05:04,160 --> 00:05:10,630 So, when I do that, it says, okay one file has been added to the git repository and 68 00:05:10,630 --> 00:05:15,300 some other information will be typed out onto that command window. 69 00:05:15,300 --> 00:05:20,440 So let's now check again, git status. 70 00:05:20,440 --> 00:05:26,220 And now you see that it says nothing to commit, working directory is clean. 71 00:05:26,220 --> 00:05:31,230 So what that means is that the current state of my working directory, or 72 00:05:31,230 --> 00:05:35,860 working folder, has been committed to the git repository. 73 00:05:35,860 --> 00:05:39,330 So a snapshot has been committed to my git repository. 74 00:05:39,330 --> 00:05:46,851 Now I can type the next command called git log --oneline. 75 00:05:46,851 --> 00:05:53,020 And see that it shows a number there, an eight digit number there. 76 00:05:53,020 --> 00:05:57,850 And then also shows the message that we put in to our commit, saying first commit. 77 00:05:57,850 --> 00:06:03,340 So that is the log of all the commits that have been put into my data repository. 78 00:06:05,120 --> 00:06:13,832 So going back to our next git command we saw that git log --oneline we'll see and 79 00:06:13,832 --> 00:06:18,540 it shows us a brief log of all the commits. 80 00:06:18,540 --> 00:06:23,920 If you simply type git log it display a lot more detail information about 81 00:06:23,920 --> 00:06:26,220 all the commits. 82 00:06:26,220 --> 00:06:30,850 But this is sufficient enough for obtaining information that we require. 83 00:06:33,350 --> 00:06:40,820 Let's now come back to our editor here in Visual Studio code. 84 00:06:40,820 --> 00:06:44,940 So I'm going to add more changes to my index.html file. 85 00:06:44,940 --> 00:06:45,945 So I will add. 86 00:06:54,298 --> 00:06:57,790 So I have changed my index.html file. 87 00:06:57,790 --> 00:07:01,750 Now let me add another folder under the GIT-TEST folder. 88 00:07:01,750 --> 00:07:07,220 So I will create a subfolder here named templates, and 89 00:07:07,220 --> 00:07:13,450 inside this templates folder, I'm going to create another file named test.html. 90 00:07:13,450 --> 00:07:17,180 This is just to show you how git can commit 91 00:07:17,180 --> 00:07:21,120 entire folder hierarchy into its repository. 92 00:07:21,120 --> 00:07:24,754 So with test.html now there, 93 00:07:24,754 --> 00:07:31,185 I'm just going to copy everything from my index.html 94 00:07:31,185 --> 00:07:36,374 into my test.html, and save the changes. 95 00:07:39,447 --> 00:07:41,484 Going back to the command line, 96 00:07:41,484 --> 00:07:45,943 let's now check out the status of our git repository and this folder. 97 00:07:45,943 --> 00:07:52,880 So typing git status shows that the index.html 98 00:07:52,880 --> 00:07:57,370 file that we have already added earlier to the repository has now been modified. 99 00:07:57,370 --> 00:08:00,207 So if there is a new version of the index index.html file. 100 00:08:00,207 --> 00:08:04,011 Also it shows that there are some untracked files in 101 00:08:04,011 --> 00:08:06,408 this folder called templates. 102 00:08:06,408 --> 00:08:11,530 Let's add all these changes to our repository, to the staging area. 103 00:08:11,530 --> 00:08:16,640 So again type git add dot and then all these 104 00:08:16,640 --> 00:08:21,620 files will be added to the staging area. 105 00:08:21,620 --> 00:08:23,940 Again, checking out the status, 106 00:08:23,940 --> 00:08:29,490 you now see that the changes that I've been added to the staging area. 107 00:08:29,490 --> 00:08:32,850 So all these files have been added to the staging area. 108 00:08:32,850 --> 00:08:34,560 Let's do one more commit. 109 00:08:34,560 --> 00:08:38,381 So I would say git commit -m. 110 00:08:40,218 --> 00:08:47,234 Second commit and then let's check out the log. 111 00:08:50,828 --> 00:08:57,480 If you check out the log you now see that there two commits in my git repository. 112 00:08:57,480 --> 00:08:59,130 The first and the second commit and 113 00:08:59,130 --> 00:09:03,040 note that each one of them is given a different number there. 114 00:09:03,040 --> 00:09:09,830 If you want to see the full details of the log, you can type simply git log and 115 00:09:09,830 --> 00:09:15,095 then you will see more details in there then what you would be interested in. 116 00:09:15,095 --> 00:09:19,115 So notice that the oneline commit 117 00:09:19,115 --> 00:09:24,405 only gives the first few characters of my commit number there. 118 00:09:24,405 --> 00:09:26,395 That is sufficient enough for us to operate with. 119 00:09:29,245 --> 00:09:35,502 Let me now go back again to my Visual Studio and to add one more. 120 00:09:44,019 --> 00:09:45,890 One more line to my index.html file. 121 00:09:47,140 --> 00:09:49,800 So now my index.html file has been modified. 122 00:09:51,660 --> 00:09:53,123 And let's save the changes. 123 00:09:55,099 --> 00:09:57,871 Going back to the command line, 124 00:09:57,871 --> 00:10:04,304 go in git status shows that the index.html file has been modified. 125 00:10:04,304 --> 00:10:10,650 So let's add this to staging area and then do a third commit. 126 00:10:10,650 --> 00:10:18,720 So let's say git add dot git status. 127 00:10:18,720 --> 00:10:22,487 Now you see that the index.html, the modified version has been added. 128 00:10:22,487 --> 00:10:26,240 Now we can say git commit. 129 00:10:31,176 --> 00:10:37,084 Third commit. 130 00:10:37,084 --> 00:10:43,810 And git log oneline, and you'll see that there are three commits in our repository. 131 00:10:43,810 --> 00:10:48,220 So now our repository contains snapshots of three different types. 132 00:10:48,220 --> 00:10:51,468 At the end of the first commit, at the end of the second commit, and 133 00:10:51,468 --> 00:10:52,985 at the end of the third commit. 134 00:10:52,985 --> 00:10:56,842 Now we also can roll back changes. 135 00:10:56,842 --> 00:11:01,590 We can revert the repository to a previous version. 136 00:11:01,590 --> 00:11:04,780 We can pull out a file out from an older commit and 137 00:11:04,780 --> 00:11:09,180 then ripple this existing file in our directly from the older commit. 138 00:11:09,180 --> 00:11:14,120 So let’s see how we can operate with these things by learning a couple more commands. 139 00:11:15,820 --> 00:11:21,450 At this stage, our index.HTML file is in the current state. 140 00:11:21,450 --> 00:11:24,795 So you can notice that it has an h1 and two p's. 141 00:11:26,530 --> 00:11:29,365 Let's now look at the next git command. 142 00:11:30,815 --> 00:11:36,185 The next git command that we're going to learn about is git checkout. 143 00:11:36,185 --> 00:11:40,300 So this checkout command allows us to checkout a file 144 00:11:40,300 --> 00:11:44,040 from a previous commit in our git repository. 145 00:11:44,040 --> 00:11:48,050 So if we don't like the current file that we have in our folder and 146 00:11:48,050 --> 00:11:51,160 we will want to go back to a previous version of the file, 147 00:11:51,160 --> 00:11:55,090 we can always check out the file from a previous commit, or 148 00:11:55,090 --> 00:12:00,230 from the current commit and then continue to work with that file. 149 00:12:00,230 --> 00:12:07,136 So let's make use of this and see some folder changes to our git repository. 150 00:12:09,137 --> 00:12:15,346 Going back to our command line, we remember that between the second and 151 00:12:15,346 --> 00:12:20,235 the third commit I made changes to my index.html file. 152 00:12:20,235 --> 00:12:25,526 Suppose I want to revert back to the index.html file from my second commit. 153 00:12:25,526 --> 00:12:33,951 So then I can simply say git checkout 900cfcf. 154 00:12:33,951 --> 00:12:40,980 So that is commit identifier, the number that identifies that particular comment. 155 00:12:40,980 --> 00:12:46,170 And then I can say, index.html and what you would notice 156 00:12:46,170 --> 00:12:53,430 is the back older file will now be checked up into my current working directory. 157 00:12:55,919 --> 00:12:58,043 Going to my Visual Studio code, 158 00:12:58,043 --> 00:13:03,340 you now notice that my index.html file has reverted to the previous version. 159 00:13:03,340 --> 00:13:07,936 So the change that made before the third commit is now gone. 160 00:13:07,936 --> 00:13:13,123 So my index.html file has been restored to 161 00:13:13,123 --> 00:13:18,750 it's a state at the end of the second comment. 162 00:13:18,750 --> 00:13:24,863 Now at the command line if I type git status. 163 00:13:24,863 --> 00:13:29,140 You'll notice like this index.html file. 164 00:13:29,140 --> 00:13:33,520 Which has reverted to what it was at the end of the second commit. 165 00:13:33,520 --> 00:13:37,710 It has now already been staged so using the git checkout 166 00:13:38,720 --> 00:13:42,930 we'll pull out an older version of the file and then replace what 167 00:13:42,930 --> 00:13:47,670 is in the current directory and then it will also check it into the staging area. 168 00:13:48,970 --> 00:13:53,960 So now if I do that and then I realize that this is what I want I can simply 169 00:13:53,960 --> 00:13:56,450 do another commit at this point. 170 00:13:56,450 --> 00:14:01,090 And then that file can be commented as the fourth commit. 171 00:14:02,710 --> 00:14:08,035 But suppose I don't like this, I want to revert back to that 172 00:14:08,035 --> 00:14:13,700 index.html file at the end of the third commit. 173 00:14:13,700 --> 00:14:21,788 Then all I can do is say git reset HEAD and 174 00:14:21,788 --> 00:14:27,404 index.html. 175 00:14:27,404 --> 00:14:31,821 So at this point what happens is that the index.html, 176 00:14:31,821 --> 00:14:36,780 the modified version that I check out is still there. 177 00:14:36,780 --> 00:14:41,275 But this file has been unstaged from the staging area. 178 00:14:43,650 --> 00:14:49,269 If you go back and look at the index.html in your editor, 179 00:14:49,269 --> 00:14:54,887 it will still show the stage at the end of the second commit 180 00:14:54,887 --> 00:15:01,250 because we had pull down that file using check out for that. 181 00:15:01,250 --> 00:15:06,072 Now if you want to revert it back to what it was at the end of the third commit 182 00:15:06,072 --> 00:15:09,490 then we do one more check out from the third commit. 183 00:15:10,540 --> 00:15:18,900 Going to our command window type git status and 184 00:15:18,900 --> 00:15:24,580 you would notice that the index.html is marked as modified, but 185 00:15:24,580 --> 00:15:31,040 it also shows this particular statement here, it says git checkout -- 186 00:15:31,040 --> 00:15:35,270 and the file link to discard the changes in the working directory. 187 00:15:35,270 --> 00:15:38,150 So that's one way you can discard the changes that you 188 00:15:38,150 --> 00:15:43,095 don't need to a particular file corresponding to the previous commit. 189 00:15:43,095 --> 00:15:45,595 So let me restore this index.html back 190 00:15:45,595 --> 00:15:48,205 to what it was at the end of the third commit. 191 00:15:48,205 --> 00:15:53,104 So to do that I will simply say git 192 00:15:53,104 --> 00:15:57,647 checkout -- index.html. 193 00:15:57,647 --> 00:16:04,278 And then, if I do git status it shows that my directory is clean and, basically 194 00:16:04,278 --> 00:16:10,520 my directory had been restored to the state of the end of the third commit. 195 00:16:12,370 --> 00:16:17,580 Going to the file in my Visual Studio code I see that 196 00:16:17,580 --> 00:16:21,060 the file has been restored back to what it was at the end of the third commit. 197 00:16:21,060 --> 00:16:25,840 So this is one way you can, if you've made changes to a file after the commit and 198 00:16:25,840 --> 00:16:28,700 you want to just discard those changes you can simply 199 00:16:28,700 --> 00:16:30,880 check out the file from the last commit. 200 00:16:30,880 --> 00:16:34,530 And then all your changes that you've done after the last commit 201 00:16:34,530 --> 00:16:36,220 will be discarded on the spot. 202 00:16:36,220 --> 00:16:40,960 So these are some basic commands that are very useful for 203 00:16:40,960 --> 00:16:44,510 you as you go to the courses in this specialization, 204 00:16:44,510 --> 00:16:49,160 because you may want to commit at the end of each exercise. 205 00:16:49,160 --> 00:16:56,220 And as you proceed forward you would still have a committed version of 206 00:16:56,220 --> 00:17:01,790 the state of your folder at the end of the previous exercise. 207 00:17:01,790 --> 00:17:06,920 So that way if you are getting out a new exercise and you discovered that you 208 00:17:06,920 --> 00:17:11,803 had made mistakes and you want to revert back to the previous commit you 209 00:17:11,803 --> 00:17:18,010 always have a way of doing that using the commands that we have just learned. 210 00:17:18,010 --> 00:17:24,430 So with this basic understanding of these few git commands, 211 00:17:24,430 --> 00:17:29,260 we will be able to proceed forward with understanding and 212 00:17:29,260 --> 00:17:33,570 using git in the courses of this specialization. 213 00:17:35,560 --> 00:17:41,260 So now, we have review the git reset for specific file or git reset 214 00:17:41,260 --> 00:17:47,970 in generally if you simply type git reset it'll restore you back to the last commit. 215 00:17:47,970 --> 00:17:51,360 So it would reset the staging area to the last commit 216 00:17:51,360 --> 00:17:55,270 without disturbing the changes that you have done to your working directory. 217 00:17:55,270 --> 00:17:58,390 So once you reset, then you can check out 218 00:17:58,390 --> 00:18:02,140 the previous version of the file that you have committed in the previous commit. 219 00:18:02,140 --> 00:18:07,380 So this way you can restore your folder back to where you were at 220 00:18:07,380 --> 00:18:10,450 the starting point of the previous commit. 221 00:18:10,450 --> 00:18:15,010 So sometimes when you are going an exercise and you realize you made mistake 222 00:18:15,010 --> 00:18:20,360 you always have a way of reverting back to a previous version. 223 00:18:20,360 --> 00:18:25,665 So with this commands, I think you're all set to use git in 224 00:18:25,665 --> 00:18:31,111 the courses of this specialization So 225 00:18:31,111 --> 00:18:34,276 at the end of this exercise, did you Git it? 226 00:18:34,276 --> 00:18:37,459 [MUSIC]