Git

Decentralized version control system.

Searching for when a given string was introduced

When you want to find out which commit first referenced a given string:

git log -S <string to search for> --source --all

See this stackoverflow answer.

Reverting commits without creating a new one

This is useful when you want to revert a set of commits, but also when you want to change them before committing again.

git revert -n <commit hashes to revert>

See the git documentation

Deleting multiple local branches

git branch -d $BRANCH_NAME will delete a local branch IFF it’s been merged with the upstream branch (or remote). If you pass in --force, then it’ll delete it regardless. git branch -D $BRANCH_NAME is a shorthand for git branch -d --force $BRANCH_NAME.

git branch -D prefix* doesn’t work (git won’t do the name completion for you). Instead, something like this will work:

git branch | grep "$PREFIX_STRING" | xargs git branch -D

Rebasing a branch onto another one.

Say you branch off my_work from develop. But you later find out you need to merge it into master. How do you merge only the commits from my_work into master without including other commits from develop?

As with most things in software, stackoverflow has the answer.

git checkout my_work
git rebase --onto master develop my_work

That is, you rebase onto the target branch, from the original branch point, with the branch you want to move.

Submodules

Submodule are a neat, basic way to manage dependencies.

Adding one is easy

git submodule add SUBMODULE_URL

When you’re not the one who added it, the command to pull down the submodules is less obvious.

git submodule update --init --recursive

Removing a submodule

Removing a submodule is less obvious, and, as of git 1.8.5, involves a 3-part process:

git submodule deinit -f -- $MODULE
rm -rf .git/modules/$MODULE
git rm -f $MODULE

Thanks to this stackoverflow answer

Generating and Applying Patches

Patch files are files (duh) describing changes between one version to another. They can be easily created by piping git diff $SOURCE_COMMIT $TARGET_COMMIT to a file. Or, for changes from HEAD to whatever’s being worked on, a simple git diff.

Once you have the patch, you can then apply it with git apply $PATH_TO_FILE, so, for example:

git diff > change.patch
git co .
git apply change.patch

Which is a less elegant version of git stash.

Stop tracking changes to a file

Use git rm --cached on the file(s), and add them to the ignore patterns.

Last updated: 2021-05-08 08:53:50 -0700