Git

Useful Git Commands

Repositories

Create a New Repo

git init
git add -A
git commit -m "first commit"
git branch -M main
git remote add origin <REPO_LINK>
git push -u origin main

Push an Existing Repo

git remote add origin <REPO_LINK>
git branch -M main
git push -u origin main

Branches

Create a Branch

The branch will be created locally, meaning that it will not be visible on GitHub.com until it's pushed.

git checkout -b <BRANCH_NAME>

Switch a Branch

Cannot switch to another branch if uncommitted changes exist on the current branch.

git checkout <BRANCH_NAME>

Push to Branch

git push origin <BRANCH_NAME>

Delete a Branch

git branch -D <BRANCH_NAME>

Rename a Local Branch

git branch -m <OLD_BRANCH_NAME>  <NEW_BRANCH_NAME>

Unstage All Changes on Local Branch

git reset

Unstage a File on Local Branch

git reset <FILE_PATH>

Divergent Branches

Sometimes, when attempting to pull changes on a branch, an error occurs with the following information:

hint: You have divergent branches and need to specify how to reconcile them.
hint: You can do so by running one of the following commands sometime before
hint: your next pull:
hint: 
hint:   git config pull.rebase false  # merge
hint:   git config pull.rebase true   # rebase
hint:   git config pull.ff only       # fast-forward only
hint: 
hint: You can replace "git config" with "git config --global" to set a default
hint: preference for all repositories. You can also pass --rebase, --no-rebase,
hint: or --ff-only on the command line to override the configured default per
hint: invocation.

The following command is the preferred way to ensure a clean, linear history. It will fetch the changes from the remote branch, and instead of merging the fetched changes into the local branch, it applies the local changes on top of the changes retrieved.

git pull --rebase origin <BRANCH_NAME>

Merge Main to Local Branch

When working on a local branch and new updates have been pushed to the main branch by someone else, it may make sense to get those changes reflected on your local branch. To do that, run the following commands:

git fetch origin
git merge origin/main

Commits

Revert to Previous Commit

git reset --hard <COMMIT_HASH>

Revert all Unstaged Changes

The following command will revert all unstaged changes on the current branch. For example, any changes seen when running git status before staging will be reverted when running the command below.

git checkout -- .

Amend Last Commit

The following is useful in the scenerio where you need to make more changes right after pushing to GitHub, but don't want to create another commit. This is a way to add new changes to the last commit without editing the commit message.

git add -A
git commit --amend --no-edit
git push -f origin <BRANCH_NAME>

Accounts

Display Username and Email in Current Repo

git config user.name
git config user.email

Change Username and Email in Current Repo

This overwrites the global config username and email.

git config user.name <USER_NAME>
git config user.email <EMAIL>

Change Username and Email Globally

This will be default config used if username and email are not set in a repo.

git config --global user.name <USER_NAME>
git config --global user.email <EMAIL>