1 00:00:00,033 --> 00:00:04,010 In this movie, I want to demonstrate a soft reset. 2 00:00:04,010 --> 00:00:08,000 So, here's the commit log. You can see that my most recent commit was reverting 3 00:00:08,000 --> 00:00:10,040 this commit that was right before it. 4 00:00:10,040 --> 00:00:14,053 What if we wanted to undo our version, that is we wanted to get rid of this? 5 00:00:14,053 --> 00:00:19,009 We could revert it and revert the reversion, or what we want to do here is 6 00:00:19,009 --> 00:00:24,049 we want to actually rewind back in time to before I made this reversion back 7 00:00:24,049 --> 00:00:27,067 to this point here. So, this is the reference we're going to use. 8 00:00:27,067 --> 00:00:31,049 We want to rewind the HEAD back to that point so that it records from 9 00:00:31,049 --> 00:00:34,058 there going forward. So, what would that look like? 10 00:00:34,058 --> 00:00:38,008 Well, the first thing is whenever I start working with moving the HEAD pointer 11 00:00:38,008 --> 00:00:42,033 around, I always think it's a good idea to open up a new text file, and let's 12 00:00:42,033 --> 00:00:46,049 just grab the most resent commits here, we can grab the first several, no big 13 00:00:46,049 --> 00:00:49,036 deal, and let's just take those and paste them in here. 14 00:00:49,036 --> 00:00:53,014 So now we always have these commits to refer to. If we need to get back here, we 15 00:00:53,014 --> 00:00:54,076 have that value recorded. 16 00:00:54,076 --> 00:00:58,016 Once we rewind, our log won't show it to us anymore. 17 00:00:58,016 --> 00:01:02,015 I'm just going to take that and put it out of the way for now. 18 00:01:02,015 --> 00:01:06,065 Let's first of all take a look at what the HEAD pointer points at now, git/HEAD. 19 00:01:06,065 --> 00:01:10,094 It points to refs/heads/master, and we saw before that, that's also a file, 20 00:01:10,094 --> 00:01:15,090 refs/heads/master, and it will always point to that file. 21 00:01:15,090 --> 00:01:20,040 So, if we ask for this, as long as we're on the master branch, it will tell us 22 00:01:20,040 --> 00:01:23,090 this answer, the real SHA that we're looking for is contained in this file. 23 00:01:23,090 --> 00:01:27,090 So, right now it points to that 5c86ebd. 24 00:01:27,090 --> 00:01:33,029 If we take a look here, you can see 5c86ebd is in fact the most recent commit. 25 00:01:33,029 --> 00:01:41,005 So now what we want to do is a soft reset, git reset --soft, and we want to 26 00:01:41,005 --> 00:01:44,045 use that second commit. Again, let's just pull it up. 27 00:01:44,045 --> 00:01:46,070 We're going to go back to this one here. 28 00:01:46,070 --> 00:01:50,074 I'm going to just copy that, and there we go, we'll paste it in here. 29 00:01:50,074 --> 00:01:54,087 Now, it's going to move the HEAD pointer back to that point in time. 30 00:01:54,087 --> 00:02:00,000 It didn't give me any kind of message there, but if I now do that same look at 31 00:02:00,000 --> 00:02:05,029 what it points to, refs/heads/ master, you can see it's changed. 32 00:02:05,029 --> 00:02:07,043 Now, it points to this other commit. 33 00:02:07,043 --> 00:02:16,076 And if I do git log, you'll see that the most recent commit looks like it's that one, the da3866. 34 00:02:16,076 --> 00:02:19,014 Now, here is what git soft does. 35 00:02:19,014 --> 00:02:25,029 If we do git status, you'll see that we have in our working directory and in our 36 00:02:25,029 --> 00:02:32,083 staging area, we have resources.html still in its most recent state, not the 37 00:02:32,083 --> 00:02:36,046 change that's in the Repo here, but the changes that we made since then. 38 00:02:36,046 --> 00:02:38,005 This is the reverted file. 39 00:02:38,005 --> 00:02:44,051 Let's take a look at the contents to see, git diff --staged, and you can see 40 00:02:44,051 --> 00:02:46,090 this is the change we made that reverted. 41 00:02:46,090 --> 00:02:51,063 So it took sunglasses, sunscreen, insect repellent and moved them back to the bottom. 42 00:02:51,063 --> 00:02:54,008 So, it did not destructively get rid of our changes. 43 00:02:54,008 --> 00:02:58,033 Our changes are still here in the staging index and in the working directory. 44 00:02:58,033 --> 00:03:02,090 We are now ready to record a new commit if we want to, and it would just record 45 00:03:02,090 --> 00:03:08,036 it over essentially where that other commit was before, a lot like if we had our 46 00:03:08,036 --> 00:03:11,036 tape recorder, and I was saying we recorded back, recorded over the last 47 00:03:11,036 --> 00:03:12,086 10 minutes of audio again. 48 00:03:12,086 --> 00:03:16,011 We are essentially forgetting about that old stuff that we were doing, and 49 00:03:16,011 --> 00:03:21,013 making new commits from here on out. Or what we can do is we can just go back to 50 00:03:21,013 --> 00:03:25,079 this most recent commit and change the HEAD pointer to point back to that, git 51 00:03:25,079 --> 00:03:31,046 reset --soft, and put the most recent one in there. 52 00:03:31,046 --> 00:03:37,001 Now, if we do git log, now our version has come back again, git status, there 53 00:03:37,001 --> 00:03:39,001 is nothing to commit. Our working directory is clean. 54 00:03:39,001 --> 00:03:43,002 So all we did was basically take the HEAD pointer from pointing at this one, 55 00:03:43,002 --> 00:03:47,060 moved it so it's pointing at this one, and then moved it back pointing to that one again. 56 00:03:47,060 --> 00:03:51,059 You can see why git reset with the soft option is the safest and least 57 00:03:51,059 --> 00:03:55,011 destructive, because it didn't actually remove anything at all. 58 00:03:55,011 --> 00:03:59,078 All it did was moved the HEAD pointer that other commit was still there, and 59 00:03:59,078 --> 00:04:03,093 all of our work was still maintained in the staging index and in our working directory. 60 00:04:03,093 --> 00:04:05,088 We didn't lose anything. 61 00:04:05,088 --> 00:04:08,093 In the next movie let's compare this to the mixed reset.