1 00:00:00,000 --> 00:00:04,402 [MUSIC] 2 00:00:04,402 --> 00:00:08,751 Let us now explore some basic Git commands that are very useful for 3 00:00:08,751 --> 00:00:10,660 us in this specialization. 4 00:00:11,670 --> 00:00:15,299 There is lot more to Git than what we cover in this exercise. 5 00:00:18,380 --> 00:00:23,779 To get started go to your convenient location on your computer and 6 00:00:23,779 --> 00:00:27,029 then create a folder named git-test. 7 00:00:30,340 --> 00:00:35,090 Then, open this folder in your favorite editor. 8 00:00:37,935 --> 00:00:42,875 Here, I have the GIT-TEST folder that we just created open in 9 00:00:42,875 --> 00:00:45,390 my Visual Studio Code. 10 00:00:45,390 --> 00:00:51,399 Let me add a file to this folder named index.html, 11 00:00:51,399 --> 00:00:55,869 now you can see that I have added in some 12 00:00:55,869 --> 00:01:00,504 HTML code into this index.html file. 13 00:01:00,504 --> 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 00:01:27,120 --> 00:01:32,650 So this is our first git command that we have learnt, git init. 20 00:01:32,650 --> 00:01:36,320 This initializes 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 kit. 23 00:01:45,690 --> 00:01:48,210 Now let's not worry about branches and so on, 24 00:01:48,210 --> 00:01:50,665 we will not deal with that in this course. 25 00:01:50,665 --> 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 tapped out on the command window. 34 00:02:28,945 --> 00:02:34,390 You see that it says on branch master, so that is the master branch that we add on. 35 00:02:34,390 --> 00:02:40,690 And it says, untracked files, and then shows index.html in red. 36 00:02:40,690 --> 00:02:43,790 On your specific computer, it may be using different colors or 37 00:02:43,790 --> 00:02:49,040 represent this differently or this is what it shows on my Mac. 38 00:02:49,040 --> 00:02:54,040 So now, this index.html file that we have just created in this folder 39 00:02:54,040 --> 00:02:58,100 is now not been added to our git repository. 40 00:02:58,100 --> 00:03:01,680 So let's go ahead and add that file to the git repository. 41 00:03:01,680 --> 00:03:07,510 So to do that, we say, git add, and you can simply say dot, 42 00:03:07,510 --> 00:03:12,350 which means that all the files in the current directory will be added to 43 00:03:12,350 --> 00:03:17,680 what is called as the staging area of my git repository. 44 00:03:17,680 --> 00:03:21,740 So now, if I again type git status, 45 00:03:21,740 --> 00:03:27,780 you will see that the file index.html is marked in green. 46 00:03:27,780 --> 00:03:34,202 And it says, changes to be committed there and then shows the file name and then so 47 00:03:34,202 --> 00:03:40,161 that means that this file is now ready to be committed to my git repository. 48 00:03:41,647 --> 00:03:46,100 So, the next command that we saw was git add. 49 00:03:46,100 --> 00:03:51,190 By using git add you can add file or folders to that staging area. 50 00:03:51,190 --> 00:03:57,250 So once you add it to the staging area, then you can commit that snapshot 51 00:03:57,250 --> 00:04:03,100 of our folder status to our git repository. 52 00:04:03,100 --> 00:04:06,460 So that means that when you do the git commit, 53 00:04:08,130 --> 00:04:12,610 what this command will do is commit the current 54 00:04:12,610 --> 00:04:17,250 state of our folders into our git repositories. 55 00:04:17,250 --> 00:04:20,380 So all the files as they exist at the moment, 56 00:04:20,380 --> 00:04:24,720 once they have been staged using the git add, then they will be committed to our 57 00:04:24,720 --> 00:04:29,510 git repository when we execute the git command folder. 58 00:04:29,510 --> 00:04:34,650 So at this point when we execute the git command, then our initial 59 00:04:34,650 --> 00:04:40,750 state will now be changed to the first commit to the git repository. 60 00:04:40,750 --> 00:04:42,650 So let's go ahead and do that. 61 00:04:45,470 --> 00:04:51,950 Back at the command prompt, let's type git commit. 62 00:04:51,950 --> 00:04:54,888 And then we can even add a message to our commit. 63 00:04:54,888 --> 00:05:00,010 So I'm going to say git commit -m "first 64 00:05:00,010 --> 00:05:04,160 commit" because this is our commit to our git repository. 65 00:05:04,160 --> 00:05:10,630 So when I do that, it says, okay, 1 file has been added to the git repository and 66 00:05:10,630 --> 00:05:15,300 some other information will be typed out on to the command window. 67 00:05:15,300 --> 00:05:20,790 So let's now check again, git status and 68 00:05:20,790 --> 00:05:26,220 now you see that it says nothing to commit, working directory is clean. 69 00:05:26,220 --> 00:05:31,230 So what it means is that the current state of my working directory or 70 00:05:31,230 --> 00:05:36,390 working folder has been committed to the git repository, so 71 00:05:36,390 --> 00:05:39,330 a snapshot has been committed to my git repository. 72 00:05:39,330 --> 00:05:47,200 Now, I can type the next command called git log --oneline, 73 00:05:47,200 --> 00:05:53,020 and see that it shows a number there, an eight digit number there, 74 00:05:53,020 --> 00:05:57,850 and then also it shows the message that we put into our commit saying first commit. 75 00:05:57,850 --> 00:06:03,340 So that is the log of all the commits that have been put into my git repository. 76 00:06:05,120 --> 00:06:08,900 So, going back to our next git command, 77 00:06:08,900 --> 00:06:14,094 we saw that git log --oneline 78 00:06:14,094 --> 00:06:18,540 will show us a brief log of all the commits. 79 00:06:18,540 --> 00:06:20,080 If you simply type git log 80 00:06:21,200 --> 00:06:26,220 display a lot more detailed information about all the commits. 81 00:06:26,220 --> 00:06:31,344 But this is sufficient enough for obtaining information that we require. 82 00:06:33,350 --> 00:06:40,248 Let's now come back to our editor here, in Visual Studio Code, 83 00:06:40,248 --> 00:06:46,141 so I'm going to add more changes to my index.html file. 84 00:06:54,501 --> 00:06:57,790 I have changed my index.html file. 85 00:06:57,790 --> 00:07:02,450 Now, let me add another folder under the git test folder, so 86 00:07:02,450 --> 00:07:07,990 I will create a subfolder here named templates, and inside these 87 00:07:07,990 --> 00:07:13,450 templates folder, I'm going to create another file name, test.html. 88 00:07:13,450 --> 00:07:16,230 This is just to show you how git 89 00:07:16,230 --> 00:07:21,120 can commit entire folder hierarchy into its repository. 90 00:07:21,120 --> 00:07:26,002 So with test.html now there, I'm just 91 00:07:26,002 --> 00:07:31,173 going to copy everything from my index.html 92 00:07:31,173 --> 00:07:36,499 into my test.html, and save the changes. 93 00:07:39,447 --> 00:07:41,484 Going back to the command line, 94 00:07:41,484 --> 00:07:46,480 let's now check out the status of our git repository and this folder. 95 00:07:46,480 --> 00:07:51,740 So type in git status, shows that 96 00:07:51,740 --> 00:07:56,020 the index status html file that we have already handed earlier to the repository 97 00:07:56,020 --> 00:08:00,570 has now been modified, so there is a newer version of the index.html file. 98 00:08:00,570 --> 00:08:03,220 Also, it shows that there are some untracked 99 00:08:03,220 --> 00:08:05,530 files in this folder called templates. 100 00:08:06,620 --> 00:08:11,794 Let's add all these changes to the staging 101 00:08:11,794 --> 00:08:16,114 the area, so again, type git add. 102 00:08:16,114 --> 00:08:21,620 And then all these files will be added to the staging area. 103 00:08:21,620 --> 00:08:23,940 Again, checking out the status. 104 00:08:23,940 --> 00:08:29,490 You now see that changes that have been added to the staging area. 105 00:08:29,490 --> 00:08:32,850 So all these files have been added to the staging area. 106 00:08:32,850 --> 00:08:36,850 Let's do one more commit, so 107 00:08:36,850 --> 00:08:42,930 I would say git commit -m, second commit and 108 00:08:42,930 --> 00:08:47,096 then let's check out the log. 109 00:08:50,874 --> 00:08:55,246 If you check out the log, you'll now see that there are two commits 110 00:08:55,246 --> 00:08:58,930 in my git repository, the first and the second commit. 111 00:08:58,930 --> 00:09:03,040 And note that each one of them is given a different number there. 112 00:09:03,040 --> 00:09:07,130 If you want to see their full details of the log, 113 00:09:07,130 --> 00:09:12,510 you can type simply, git log and then you'll receive more details in there. 114 00:09:12,510 --> 00:09:15,132 Then what you would be interested in. 115 00:09:15,132 --> 00:09:20,114 So, notice that the oneline commit only gives the first 116 00:09:20,114 --> 00:09:24,405 few characters of my commit number there. 117 00:09:24,405 --> 00:09:27,028 That is sufficient enough for us to operate with. 118 00:09:29,245 --> 00:09:34,721 Let me now go back again to my Visual Studio, and then add one more. 119 00:09:43,885 --> 00:09:47,140 One more line to my index.html file. 120 00:09:47,140 --> 00:09:49,800 So now my index.html file has been modified. 121 00:09:51,660 --> 00:09:53,170 And let's save the changes. 122 00:09:55,310 --> 00:09:58,530 Going back to the command line, doing git 123 00:09:59,870 --> 00:10:04,490 status shows that index.html file has been modified. 124 00:10:04,490 --> 00:10:10,650 So let's add this to the staging area, and then do a third commit. 125 00:10:10,650 --> 00:10:15,716 So let's say, git add., 126 00:10:15,716 --> 00:10:18,720 git status, 127 00:10:18,720 --> 00:10:22,700 now you see that the index.html the modified version has been added. 128 00:10:22,700 --> 00:10:27,722 Now we can say git commit. 129 00:10:31,231 --> 00:10:36,825 "third commit" and do git log --oneline, 130 00:10:36,825 --> 00:10:43,810 and you see 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 points, 132 00:10:48,220 --> 00:10:51,370 at the end of the first commit, at the end of the second commit, and 133 00:10:51,370 --> 00:10:53,250 at the end of the third commit. 134 00:10:53,250 --> 00:10:56,930 Now, we also can roll back changes, 135 00:10:56,930 --> 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 from an older commit, and 137 00:11:04,780 --> 00:11:09,180 then replace the existing directory from the old commit. 138 00:11:09,180 --> 00:11:12,370 So, let's see how we can operate with these things 139 00:11:12,370 --> 00:11:14,120 by learning a couple of more commands. 140 00:11:15,820 --> 00:11:21,450 At this stage, our index.html file is in the current state. 141 00:11:21,450 --> 00:11:24,795 So you can notice that it has an h1 and two ps. 142 00:11:26,530 --> 00:11:29,365 Let's now look at the next git command. 143 00:11:30,815 --> 00:11:36,185 The next git command that we are going to learn about is git checkout. 144 00:11:36,185 --> 00:11:40,300 So this checkout command allows us to check out a file 145 00:11:40,300 --> 00:11:44,040 from a previous commit in our git repository. 146 00:11:44,040 --> 00:11:48,050 So if we don't like the current file that we have in our folder and 147 00:11:48,050 --> 00:11:51,160 we want to go back to your previous version of the file, 148 00:11:51,160 --> 00:11:55,090 we can always check out the file from a previous commit or 149 00:11:55,090 --> 00:12:00,230 from the current commit and then continue to work with that file. 150 00:12:00,230 --> 00:12:07,431 So let's make use of this and see some further changes to our git repository. 151 00:12:09,228 --> 00:12:15,366 Going back to our command line, we remember that, between the second and 152 00:12:15,366 --> 00:12:20,235 the third commit, I made changes to my index.html file. 153 00:12:20,235 --> 00:12:25,735 Suppose I want to revert back to the index.html file from my second commit. 154 00:12:25,735 --> 00:12:29,885 So then, I can simply say, 155 00:12:29,885 --> 00:12:34,039 git checkout 900cfcf. 156 00:12:34,039 --> 00:12:41,035 So that is commit identify the number that identifies the particular commit, 157 00:12:41,035 --> 00:12:46,971 and then I can say index.html, and what you would notice is that, 158 00:12:46,971 --> 00:12:53,662 that older file will now be checked out into my current working directory. 159 00:12:55,845 --> 00:12:58,018 Going to my Visual Studio Code, 160 00:12:58,018 --> 00:13:03,811 you'll now notice that my index.html file has reverted to the previous working so, 161 00:13:03,811 --> 00:13:08,580 the change that I made before the third commit it is now gone. 162 00:13:08,580 --> 00:13:16,690 So my index.html file has been restored to its state at the end of the second commit. 163 00:13:18,920 --> 00:13:23,042 Now, at the command line, if I try git status, 164 00:13:23,042 --> 00:13:28,403 you'll notice that this index.html file which was reverted 165 00:13:28,403 --> 00:13:35,470 to what it was at the end of the second commit, it has now already been staged. 166 00:13:35,470 --> 00:13:40,930 So using this git checkout, we'll pull out an older version of the file, 167 00:13:40,930 --> 00:13:44,390 and then replace what is in the current directory, and 168 00:13:44,390 --> 00:13:47,670 then it'll also check it into the staging area. 169 00:13:48,970 --> 00:13:53,400 So now if I do that and then I realize that this is what I want, 170 00:13:53,400 --> 00:13:56,450 I can simply do another commit at this point. 171 00:13:56,450 --> 00:14:02,445 And then that file can be committed as the fourth commit. 172 00:14:02,445 --> 00:14:07,812 But suppose I don't like this, I want to double 173 00:14:07,812 --> 00:14:12,641 to back to the index.html file at the end of 174 00:14:12,641 --> 00:14:18,291 the third commit then all I can do is say git reset, 175 00:14:20,339 --> 00:14:25,698 HEAD and index.html. 176 00:14:28,236 --> 00:14:33,356 So at this point, what happens is that the index.html, 177 00:14:33,356 --> 00:14:38,796 the modified version that I had checked out is still there but 178 00:14:38,796 --> 00:14:43,397 this file has been unstaged from the staging area. 179 00:14:43,397 --> 00:14:49,803 If you go back and look at the index.html in your editor, 180 00:14:49,803 --> 00:14:56,680 it will still show the state at the end of the second commit. 181 00:14:56,680 --> 00:15:01,250 Because we had pulled out the file using checkout for that. 182 00:15:01,250 --> 00:15:06,900 Now, if you want to revert it back to what it was at the end of the third commit, 183 00:15:06,900 --> 00:15:11,956 then we do one more checkout from the third commit going to our 184 00:15:11,956 --> 00:15:18,900 command window, type git status and 185 00:15:18,900 --> 00:15:23,920 you would notice that the index.html is marked as modified. 186 00:15:23,920 --> 00:15:28,870 But it also shows this particular statement here. 187 00:15:28,870 --> 00:15:32,270 It says git checkout -- and 188 00:15:32,270 --> 00:15:35,310 the file name, to discard the changes in the working directories. 189 00:15:35,310 --> 00:15:39,270 So that's one way you can discard the changes that you have made to a particular 190 00:15:39,270 --> 00:15:43,095 file corresponding to the previous comment. 191 00:15:43,095 --> 00:15:46,875 So let me just restore that index.html back to what it was at the end of 192 00:15:46,875 --> 00:15:48,205 the third commit. 193 00:15:48,205 --> 00:15:52,455 So to do that, I could simply say git, checkout, 194 00:15:52,455 --> 00:15:58,540 -- index.html and then, 195 00:15:58,540 --> 00:16:05,480 if I do git status, it shows that my directory is clean. 196 00:16:05,480 --> 00:16:08,130 And basically my directory has been restored to 197 00:16:08,130 --> 00:16:10,520 the state at the end of the third commit. 198 00:16:12,370 --> 00:16:17,580 Going to the file in my Virtual Studio Code, I see that 199 00:16:17,580 --> 00:16:21,060 their file has been restored back to what it was at the end of the third cap. 200 00:16:21,060 --> 00:16:24,740 So this is one way you can, if you have made changes to your 201 00:16:24,740 --> 00:16:27,740 file after the commit and you want to just discard those changes, 202 00:16:27,740 --> 00:16:31,810 you can simply check out the file from the last commit, and then all your 203 00:16:31,810 --> 00:16:36,220 changes that you've done after the last commit will be discarded on the spot. 204 00:16:36,220 --> 00:16:40,960 So these are some basic commands that are very useful for 205 00:16:40,960 --> 00:16:44,510 you as you go through the courses in this specialization 206 00:16:44,510 --> 00:16:49,160 because you may want to commit at the end of each exercise. 207 00:16:49,160 --> 00:16:56,220 And as you proceed forward, you would still have a guided vision of 208 00:16:56,220 --> 00:17:01,790 the state of your folder at the end of the previous exercise. 209 00:17:01,790 --> 00:17:06,180 So that way, if you're carrying out a new exercise and you've discovered that you've 210 00:17:06,180 --> 00:17:10,320 made mistakes and you want to revert back to the previous commit, 211 00:17:10,320 --> 00:17:18,000 you always have a way of doing that using the commands that we have just let. 212 00:17:18,000 --> 00:17:24,430 So with this basic understanding of this few git commands, 213 00:17:24,430 --> 00:17:29,260 you'll be able to proceed forward with understanding and 214 00:17:29,260 --> 00:17:33,570 using git in the courses of this specialization. 215 00:17:35,560 --> 00:17:41,685 So now, we have reviewed the git reset for a specific file or git reset in general. 216 00:17:41,685 --> 00:17:47,970 If you simply type git reset, it'll restore you back to the last commit. 217 00:17:47,970 --> 00:17:50,680 So it will reset the staging area to the last commit, 218 00:17:50,680 --> 00:17:55,270 without disturbing the changes that you have done to your working directory. 219 00:17:55,270 --> 00:17:58,390 So once you reset, then you can check out 220 00:17:58,390 --> 00:18:02,140 the previous version of the file that you have committed in the previous commit. 221 00:18:02,140 --> 00:18:07,380 So this week, you can restore your folder back to the where you were at 222 00:18:07,380 --> 00:18:10,450 the starting point of the previous commit. 223 00:18:10,450 --> 00:18:15,300 So sometimes when you are going through an exercise and you realize you missed a cue. 224 00:18:15,300 --> 00:18:20,174 Always have a way of reverting back to a previous version. 225 00:18:20,174 --> 00:18:25,027 So with these commands, I think you're all set to go ahead to 226 00:18:25,027 --> 00:18:28,849 use git in the courses of this specialization. 227 00:18:31,070 --> 00:18:34,395 So at the end of this exercise, did you Git it? 228 00:18:34,395 --> 00:18:37,459 [MUSIC]