社内勉強会のメモ。
コミットとブランチ編
親コミットと子コミット
新しくブランチを作ると同じコミットを参照している
.git/HEAD で今どこのブランチを参照しているかがわかる
.git/refs/head/ブランチ名 ブランチの最新コミットを参照している
USER@USER-THINK ~/projects/sandbox $ git branch --verbose --all * master ca38ca1 [ahead 1] Child commit. remotes/origin/HEAD -> origin/master remotes/origin/master 4fb4c83 Merge pull request #1 from shigemk2/shigemk2 remotes/origin/shigemk2 6d60fab Add hoge USER@USER-THINK ~/projects/sandbox $ git branch newbranch USER@USER-THINK ~/projects/sandbox $ git branch --verbose --all * master ca38ca1 [ahead 1] Child commit. newbranch ca38ca1 Child commit. remotes/origin/HEAD -> origin/master remotes/origin/master 4fb4c83 Merge pull request #1 from shigemk2/shigemk2 remotes/origin/shigemk2 6d60fab Add hoge USER@USER-THINK ~/projects/sandbox $ ll .git/refs/heads/ total 2 -rw-r--r-- 1 USER Administrators 41 Sep 12 15:12 master -rw-r--r-- 1 USER Administrators 41 Sep 12 15:16 newbranch USER@USER-THINK ~/projects/sandbox $ cat .git/refs/heads/master .git/refs/heads/newbranch ca38ca1d067a3df13ea6b9b0d8b1d14001f26a83 ca38ca1d067a3df13ea6b9b0d8b1d14001f26a83
USER@USER-THINK ~/projects/sandbox $ cat .git/refs/heads/master .git/refs/heads/newbranch 6023fdaafc7a8536cdf71ea0f04544841a29f37c 386b95eb316c5f53f32e4f862268304dbba91696 USER@USER-THINK ~/projects/sandbox $ git log --oneline 386b95e Commit on newbranch. ca38ca1 Child commit. 4fb4c83 Merge pull request #1 from shigemk2/shigemk2 6d60fab Add hoge 2998c7d Create test2.txt bf250f8 Create test.txt c7fcaac Initial commit USER@USER-THINK ~/projects/sandbox $ git checkout master Switched to branch 'master' Your branch is ahead of 'origin/master' by 2 commits. (use "git push" to publish your local commits) USER@USER-THINK ~/projects/sandbox $ git log --oneline 6023fda Second Child commit. ca38ca1 Child commit. 4fb4c83 Merge pull request #1 from shigemk2/shigemk2 6d60fab Add hoge 2998c7d Create test2.txt bf250f8 Create test.txt c7fcaac Initial commit
git checkout
HEADが参照しているブランチを変えられる
git checkoutで最新コミットを変更する
USER@USER-THINK ~/projects/sandbox $ git checkout ca38ca1 Note: checking out 'ca38ca1'. You are in 'detached HEAD' state. You can look around, make experimental changes and commit them, and you can discard any commits you make in this state without impacting any branches by performing another checkout. If you want to create a new branch to retain commits you create, you may do so (now or later) by using -b with the checkout command again. Example: git checkout -b new_branch_name HEAD is now at ca38ca1... Child commit. USER@USER-THINK ~/projects/sandbox $ cat .git/HEAD ca38ca1d067a3df13ea6b9b0d8b1d14001f26a83
$ cat .git/refs/heads/master .git/refs/heads/test 6023fdaafc7a8536cdf71ea0f04544841a29f37c ca38ca1d067a3df13ea6b9b0d8b1d14001f26a83 USER@USER-THINK ~/projects/sandbox $ git reset --hard master HEAD is now at 6023fda Second Child commit. USER@USER-THINK ~/projects/sandbox $ cat .git/refs/heads/master .git/refs/heads/test 6023fdaafc7a8536cdf71ea0f04544841a29f37c 6023fdaafc7a8536cdf71ea0f04544841a29f37c
コミットがmasterまで巻き戻っている
git merge
merge
一番怖いコマンド rebase
- リポジトリを整理
- ブランチを消すと、.git/refs/heads/からブランチ名のファイルが消える
rebaseすると…
USER@USER-THINK ~/projects/sandbox $ git log --oneline 22b45ea test2 commit 2 baabcb1 test2 commit 1 731f9a5 Merge 386b95e Commit on newbranch. 6023fda Second Child commit. ca38ca1 Child commit. 4fb4c83 Merge pull request #1 from shigemk2/shigemk2 6d60fab Add hoge 2998c7d Create test2.txt bf250f8 Create test.txt c7fcaac Initial commit USER@USER-THINK ~/projects/sandbox $ cat .git/refs/heads/test2 22b45eaabcd90a8bc8b394794198b781744ab7a2 USER@USER-THINK ~/projects/sandbox $ git branch master * test2 USER@USER-THINK ~/projects/sandbox $ git rebase master First, rewinding head to replay your work on top of it... Applying: test2 commit 1 Applying: test2 commit 2 USER@USER-THINK ~/projects/sandbox $ ls -1 LICENSE README README.md hoge.txt master-test-file test.txt test2-test-file test2.txt USER@USER-THINK ~/projects/sandbox $ git log --oneline 1e45241 test2 commit 2 556ecc5 test2 commit 1 d1a0c5c master commit 2 d9f34cd master commit 1 731f9a5 Merge 386b95e Commit on newbranch. 6023fda Second Child commit. ca38ca1 Child commit. 4fb4c83 Merge pull request #1 from shigemk2/shigemk2 6d60fab Add hoge 2998c7d Create test2.txt bf250f8 Create test.txt c7fcaac Initial commit USER@USER-THINK ~/projects/sandbox $ cat .git/refs/heads/test2 1e45241864e4be33a3f1d109f4c2bb6c0dca19ad
対象となるコミットハッシュが書き換えられる。また、heads/test2も書き換えられる コミットログのラインが一本になる。
2つのブランチが分岐された時点から、現在のブランチを切り離して、もうひとつのブランチの最新のコミットに移動させる 履歴はきれいになるけど、コンフリクトが起こるときは起こる
レビュー
- git branch 新しいブランチを作る
- git checkout HEADが参照しているブランチを変更する
- git reset 現在のブランチが参照しているコミットを変更
- git rebase ブランチごとを移住
そのキーとなるのは .git/HEAD
