Basic Operations

git clone <repository-url>   # Clone a repository

git add .
git commit -m 'description'   # Stage and commit changes

git pull                    # Fetch and merge remote changes
git pull --rebase           # Pull with rebase instead of merge

git checkout main           # Switch to main branch
git checkout a1b2c3d4        # Checkout specific commit by hash
git merge develop            # Merge develop branch into current branch
git push                    # Push commits to remote
git push origin HEAD:refs/for/main   # Push for code review

Creating a Local Branch and Pushing to Remote

git branch feature-auth-module      # Create local branch
git checkout feature-auth-module    # Switch to new branch
git merge main                      # Optional: merge from main
git add .
git commit -m 'fix(): add local branch'
git push --set-upstream origin feature-auth-module   # Push and set upstream
git pull                           # Fetch latest remote changes

Deleting Branches

git branch --delete develop          # Delete local branch
git push origin --delete branch-name  # Delete remote branch

If deletion fails, use force delete:

git branch -D develop

The -D flag is an alias for --delete --force, which removes the branch without checking merge status.

Cherry-Picking a Single Commit

git cherry-pick <commit-hash>

This applies the changes from a specific commit onto your current branch.

Reverting a Merge

To undo a merge operation, use git reset. The --soft option preserves changes in the staging area, while --hard discards all modificatinos.

To keep merged changes but undo the commit:

git reset --soft HEAD~1

To discard all changes since the merge:

git reset --hard HEAD~

HEAD~1 refers to the parent commit of the current HEAD, which is the state before the merge occurred.

Warning: The --hard option permanently discards all uncommitted changes. Verify with git status and git log before proceednig.

SSH Key Setup

Configure username and email globally:

git config --global user.name "developer"
git config --global user.email "developer@example.com"

Generate SSH key (press Enter through all prompts):

ssh-keygen -t rsa

Display the public key:

cat ~/.ssh/id_rsa.pub

Migrating a Repository

Step 1: Clone the old repository as a bare mirror

git clone --mirror <old-repo-url>
cd <repo-name>.git

Step 2: Update the push URL to the new repository

git remote set-url --push origin <new-repo-url>

Step 3: Push everything to the new repository

git push --mirror

Undoing a Commit

To revert a commit while keeping changes staged:

git reset --soft HEAD~1

• HEAD~1 moves back one commit
• --soft leaves changes staged (similar to after git add)

If changes have already been pushed to a remote repository and you want to preserve history, use git revert instead, which creates a new commit that undoes the changes. The git reset --soft approach is preferred for local-only corrections.