Git tips and tricks

Git is arguably the foundation tool of Open Source and software engineering (VCS) part in general, second biggest gift of Linus Torvals to the world after the mighty Linux! If you are new to the world of OSS, git is probably the first tool you should learn about! While getting starting with git is very easy, mastering git is a lifetime endeavour! So this article would be forever in WIP, I’ll keep adding notes to it, so that anyone (including me) can keep visiting.

• If you want to set a particular file to some branch’s version on origin without disturbing other files in the branch you can use git checkout origin/<branch-name> --path/to/the/file.
  For eg, if I want to set xyz.go file to the master version you can do:-
  git checkout origin/master --xyz.go

• Sometimes, we are not ready to commit yet but want to change the branch or we realise that we have been making changes in a wrong branch. In that case git stash can be useful. What is does is, it saves your current changes in a stack and makes the status clean (i.e no diff). Now you can change your branch or do whatever is needed, and then when you want those stashed changes back, you apply selected stash from the stack.

  1. To save current changes to the stack git stash save "message".
  2. List all the saved changes in the stack git stash list.
     
  3. To apply the selected stash git stash apply <stash id>.
  4. If you want to apply last saved stash git stash pop (same concept as stack ADT)
  5. If you want to delete particular stash git stash drop <stash-id>.
  6. If you want to delete all the saved changes in you stash git stash clear.

• Cherry-picking in git:-

  In git if you have the commit ID of a commit you can use it in any branch/MR/PR. Steps:-

  • Copy the commit ID of the commit that you want to use somewhere else.
  • Go to the required branch, then do git cherry-pick <ID>.
  • That commit will be added to the current branch.

• If you want to go back to a certain commit in git do :-
  Git reset --hard <commit-hash>

• If you want to undo the changes made in a certain commit do :-
  Git revert <commit-hash>

• If you want to create a new branch out of a remote branch you can use:-

  git checkout -b <new-branch> origin/<source-branch>
  or, recently it is observed that, if you git checkout <branch> and if a branch with same name already exists in the origin, it will start tracking the branch of origin automatically.

• If a feature,bug,etc branch of yours is very behind than develop or master (whatever is the eventual target), then doing merge (by git pull origin <master/develop>) is less troublesome than rebasing. Although, under normal conditions rebase is better alternative to merge since it keeps the git history pristine.

• Running a command with -n flag tells what will happen when you run the command. It is like a test run.

• The untracked files can be removed using git clean -f -d

• Synchronize the repo with the state of the repo on the origin: git reset --hard <origin-name>