Since the last time I’ve shared a set of tips and tricks about Git, I’ve learned new ones that I regularly use. Again, hope they could help you as they helped me. Enjoy!
How to show the difference between two branches for a same file?
While you’re coding into a <file> on a feature branch feature/mybranch, it is often useful to see exactly what you’ve changed. It’s time to get a diff with the master branch:
git diff master HEAD -- <file>
git diff master -- <file>
You suddenly remember that one colleague told you he is also working on the same file in his own branch feature/hisbranch. You’re curious to see the changes he made compared with the yours:
git diff feature/hisbranch HEAD -- <file>
How to stop tracking a file?
An output <file> is tracked when it shouldn’t be. You put it into .gitignore, but it’s still there. It’s because you need to remove it from the index with
git rm --cached <file>
Then, you just need to commit that change
How to show the diff with the staged changes?
You’ve staged several changes at different moments, so you’re not sure anymore what were your changes exactly. You would like to inspect them before committing. Just type
git diff --cached
How to pick only a part of a given commit?
Someone has just merged a branch containing an important security fix that you would like to apply in your feature branch. But the fix wasn’t committed alone. There are other changes that don’t interest you. You only want a part of the commit. First of all, you need to cherry pick it and put in stage
git cherry-pick -n <commit>
Then, unstage all the changes
Stage only the changes containing the security fix
git add <file>
Finally commit them.
How to dry run merge?
You don’t like surprises. Before merging master into a feature branch, you would like to dryly run the merge. First you need to retrieve the common ancestor
git merge-base HEAD master
Then, you can run the merge in memory with git merge-tree
git merge-tree <sha-obtained-with-merge-base> master HEAD
That will give you the result of a merge without changing the working copy.
How to prune all your local branches that track an already-deleted remote branch?
You’re tracking some remote branches, but you don’t know that some of them have been remotely deleted. Git pull won’t remove those ones when you pull, you need to delete them with a specific command:
git remote prune origin --dry-run
will give you a list of staled remote branches. If you’re ok with that list, you can effectively prune them without the parameter –dry-run
git remote prune origin
That’s it for today.
Do you have you a git command that you use daily? Don’t hesitate – please share it!