Git

Basic Concepts

• Working Directory
• Staging Area (.git/index)
• .git directory

Useful Commands

• Configuration files

  • Repository config file: .git/config

  • System config file: ~/.gitconfig

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    [core] repositoryformatversion = 0 filemode = false bare = false logallrefupdates = true worktree = C:/git/myrepo ignorecase = true [submodule] active = . [remote "origin"] url = https://git-codecommit.ap-southeast-1.amazonaws.com/v1/repos/myrepo fetch = +refs/heads/*:refs/remotes/origin/* [branch "master"] remote = origin merge = refs/heads/master [branch "release/prod"] remote = origin merge = refs/heads/release/prod remote = origin merge = refs/heads/release/preprod [branch "release/test"] remote = origin merge = refs/heads/release/test [branch "release/dev"] remote = origin merge = refs/heads/release/dev

• git remote

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  $ git remote show origin $ git remote -v origin https://git-codecommit.ap-southeast-1.amazonaws.com/v1/repos/myrepo (fetch) origin https://git-codecommit.ap-southeast-1.amazonaws.com/v1/repos/myrepo (push) $ git remote show origin * remote origin Fetch URL: https://git-codecommit.ap-southeast-1.amazonaws.com/v1/repos/myrepo Push URL: https://git-codecommit.ap-southeast-1.amazonaws.com/v1/repos/myrepo HEAD branch: master Remote branches: develop tracked feature/test tracked master tracked release/dev tracked release/preprod tracked release/prod tracked release/test tracked Local branches configured for 'git pull': master merges with remote master release/dev merges with remote release/dev release/preprod merges with remote release/preprod release/prod merges with remote release/prod release/test merges with remote release/test Local refs configured for 'git push': master pushes to master (up to date) release/dev pushes to release/dev (up to date) release/preprod pushes to release/preprod (up to date) release/prod pushes to release/prod (up to date) release/test pushes to release/test (up to date)

• git push [repository] [refspec]

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  $ git status On branch release/preprod $ git push Everything up-to-date

• git rebase (current branch is topic)

          A---B---C topic*
         /
    D---E---F---G master
  
    git rebase master
    git rebase master topic
  
                  A'--B'--C' topic*
                 /
    D---E---F---G master
  
  

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  $ git log --oneline c60c0d9 (HEAD -> release/dev, origin/release/dev) Upgrade node version 16675e8 Update oracledb version e5461ba Update oracledb version 4e70188 Change Nodejs version to 14 52cf369 Add GEO IP City Function 52cf369 -- 4e70188 -- e5461ba -- 16675e8 -- c60c0d9 Squash 4e70188 -- e5461ba -- 16675e8 -- c60c0d9 into one commit $ git rebase -i 52cf369 pick 4e70188 Change Nodejs version to 14 squash e5461ba Update oracledb version # meld into previous commit squash 16675e8 Update oracledb version # meld into previous commit squash c60c0d9 Upgrade node versiong # meld into previous commit 52cf369 -- d59392d $ git log --oneline d59392d Update Nodejs version to 14 and oracledb version 52cf369 Add GEO IP City Function

• git merge (current branch is master)

    A---B---C topic
    /
    D---E---F---G master*
  
    git merge topic
  
    A---B---C topic
    /         \
    D---E---F---G---H master*
    

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  # Merge topic with current branch $ git merge topic Updating ea2980a..532a0fa Fast-forward README.md | 2 +-

• git pull
  git fetch followed by git merge or git rebase (with --rebase)

  FETCH_HEAD is a short-lived ref, to keep track of what has just been fetched from the remote repository

      A---B---C master on origin
     /
    D---E---F---G master*
    ^
    origin/master in your repository  
  
      A---B---C origin/master
     /         \
    D---E---F---G---H master
  
  

• git fetch
  git fetch --all Fetch all remote branches
  git fetch origin master Fetch only remote master branch

• git commit
  Record changes to the repository
  -a Automatically stage modified and deleted files but new files are not affected (use git add for new files)

• git add
  Add file contents to the staging area(index)

• git checkout
  Switch branches or restore working tree files
  git checkout [<branch>]
-b - create a new branch
  -B - create a new branch or reset the branch

• git show
  Shows one or more objects (blobs, trees, tags and commits).

• git log
  --oneline

• ancestry references
  ^: the parent of that commit
  ^2: the second parent of that commit (from the branch that was merged (say, topic))
  ~: first parent
  ~2: first parent of first parent (it traverses the first parents the number of times you specify)
  ~~: first parent of first parent