git

• Show file content (any branch): git cat-file main:<filename>
  Ref. git cat-file

• Rename current branch: git branch -m <newname>

• Show local branch name: git rev-parse --abbrev-ref HEAD

• Update and merge main into current branch:

  • git fetch origin main:main
  • git merge origin/main

• Push all branches: git push -u origin --all

• Swap remote: git remote set-url origin <new_origin_url>

• Check which branches have been merged : git branch --merged

• Compare 2 branches: git diff branch1..branch2

• Show commits in the current branch only
  git log <branchoff_name>^..HEAD
  (where branchoff_name is the name of the branch the current one has been branched off from)

• Remove last (local-only) commit: git reset --soft HEAD~

• Remove more than one (N) commit: git reset --soft HEAD~N

• Change case of a file when working on macOS: git mv UPPERCASE uppercase

• Fix broken commits and push: On undoing, fixing, or removing commits in git

• Cleaning up repos

  • Analyze (git-sizer or git-filter-repo)
    brew install git-sizer
git-sizer

    or

    pip install git-filter-repo git-filter-repo --analyze open .git/filter-repo/analysis

  • Remove files from history Ref. git-filter-repo
    git-filter-repo --invert-paths --path '<filename>'
    or use a text file with the list of paths to be deleted
    git-filter-repo --invert-paths --paths-from-file <tobedeleted_file_list>

• Find a file in any branch

  • git log --all -<filepath>

  or

  • git log --all -'**/<filename>'

• Find branch where a file is

  • git log --all -somefile

    returns commit_nr

  git branch -a --contains <commit_nr>

  returns otherbranch

• Show the commit tree in the cli: git log --pretty=oneline --graph --decorate --all

• Remove untracked files

  • git clean -n (dry run)
  • git clean -f

• Automate access token

  • For multiple repos

    B64_PAT=$(printf ":%s" "$SYSTEM_ACCESSTOKEN" | base64)
    git config --global http.https://dev.azure.com/.extraheader "Authorization: Basic $B64_PAT"
    git config --global --unset http.https://dev.azure.com/.extraheader
    

    But the above leaves the token in the git config file. So remember to remove it with:
    git config --global --unset http.https://dev.azure.com/.extraheader

  • For only one repo
    git -c http.extraheader="Authorization: Basic $B64_PAT" clone ...

  Note: Bearer often does not work.

• Squash commits on merge

  git merge --squash # automatic, might fail git rebase -i # interactive

• git tag

• Work with multiple branch at the same time

  git worktree add <path> <branch_name>
  git worktree list
  git worktree remove <worktree-name>
  

• Rename local and remote branch

  git checkout <old_name>
  git branch -m <new_name>
  git push origin -u <new_name>
  git push origin --delete <old_name>
  

• Rewrite commit author and committer

  git filter-branch --commit-filter '
        if [ "$GIT_COMMITTER_EMAIL" = "WRONG_COMMITTER_EMAIL" ];
        then
                GIT_AUTHOR_NAME="RIGHT_COMMITTER";
                GIT_AUTHOR_EMAIL="RIGHT_COMMITTER_EMAIL";
                GIT_COMMITTER_NAME="RIGHT_COMMITTER";
                GIT_COMMITTER_EMAIL="RIGHT_COMMITTER_EMAIL";
                git commit-tree "$@";
        else
                git commit-tree "$@";
        fi' HEAD
  git push -f --all
  

Submodules

External ref.

• Add

  git submodule add http://submodule submodule
  git add .
  git commit -m “added submodule”
  git push
  

• Clone

  git clone --recursive --jobs 6 https://module
  cd module
  

• Pull

  git pull --recurse-submodules
  

• Update submodule updated elsewehre

  cd submodule
  git checkout master
  git pull # pull the latest commit from the submodule repo
  cd ..
  git add .
  git commit -m “updated submodule”
  git push
  

• Updated submodule with local changes

  cd submodule
  touch changedfile.txt
  git add .
  git commit -m “changes to submodule”
  git push
  cd ..
  git add .
  git commit -m “updated submodule”
  git push
  

• Avoid pushing module before submodule. If we make the following mistake:

  cd submodule
  touch changedfile.txt
  git add .
  git commit -m “added changedfile.txt”
  # here we forget git push
  cd ..
  git add .
  git commit -m “updated submodule”
  git push
  

  We must correct it this way:

  git clone --recursive --jobs 6 https://module 
  # the above will return some errors trying to clone submodule
  cd module/submodule
  git checkout master
  git pull
  cd ..
  git add .
  git commit -m “fixed submodule”
  git push
  

• Remove a submodule

  git rm submodule
  git add .
  git commit -m “removed submodule”
  git push
  

References

• 50 Shades of git