git-expert

# Change commit message
git commit --amend -m "new message"
 
# Add forgotten files
git add forgotten-file.txt
git commit --amend --no-edit

# Create new commit that undoes changes
git revert commit-hash
 
# Revert multiple commits
git revert commit1 commit2 commit3
 
# Revert merge commit
git revert -m 1 merge-commit-hash

# File deleted but not committed
git checkout HEAD file.txt
 
# File deleted and committed
git log --all --full-history -- file.txt
git checkout commit-hash -- file.txt

# Dry run
git clean -n
 
# Remove files
git clean -f
 
# Remove files and directories
git clean -fd
 
# Remove files, directories, and ignored files
git clean -fdx

# Remove remote-tracking branches that no longer exist
git fetch --prune
 
# Delete merged branches
git branch --merged | grep -v "\*" | xargs -n 1 git branch -d

# Remove file from history (CAUTION: rewrites history)
git filter-branch --tree-filter 'rm -f large-file.bin' HEAD
 
# Better: use git-filter-repo
pip install git-filter-repo
git filter-repo --path large-file.bin --invert-paths
 
# Garbage collection
git gc --aggressive --prune=now

# Detached HEAD state
git checkout -b temp-branch    # Create branch from detached HEAD
 
# Accidentally committed to main instead of branch
git branch feature-branch      # Create branch at current commit
git reset --hard origin/main   # Reset main to remote
git checkout feature-branch    # Switch to feature branch
 
# Need to pull but have local changes
git stash
git pull
git stash pop
 
# Push rejected (non-fast-forward)
git pull --rebase origin main
git push
 
# Large files stuck in history
git filter-repo --strip-blobs-bigger-than 10M
 
# Corrupted repository
git fsck --full                # Check for corruption
git reflog expire --expire=now --all
git gc --prune=now --aggressive