Git Internals and Plumbing

git hash-object -w path/to/file

# Store file content as a blob and print its object ID.

printf "hello
" | git hash-object -w --stdin

# Write blob content from standard input.

git cat-file -t <object_sha>

# Show object type.

git cat-file -s <object_sha>

# Show object size in bytes.

git cat-file -p <object_sha>

# Display object content.

git count-objects -vH

# Show object counts and disk usage.

git ls-files

# Print index entries.

git ls-files --stage

# Include mode, object ID, and stage number.

git update-index --assume-unchanged path/to/file

# Hint that Git should skip stat checks for a path.

git update-index --skip-worktree path/to/file

# Tell Git to avoid touching a path in sparse-like workflows.

git write-tree

# Create a tree object from the index.

git read-tree HEAD

# Populate index from a tree-ish.

git show-ref

# List local refs and object IDs.

git for-each-ref --format='%(refname:short) %(objectname:short)' refs/heads

# Script-friendly ref iteration.

git update-ref refs/heads/tmp <commit_sha>

# Create or move a ref directly.

git symbolic-ref HEAD

# Print the symbolic target of HEAD.

git pack-refs --all --prune

# Store refs efficiently in packed-refs.

echo "commit message" | git commit-tree <tree_sha> -p <parent_sha>

# Create a commit object directly.

git rev-list HEAD

# Enumerate commits reachable from HEAD.

git rev-list --objects HEAD

# Enumerate reachable objects.

git diff-tree --stat HEAD~1 HEAD

# Compare tree objects without porcelain diff.

git rev-parse --verify HEAD^{commit}

# Ensure a revision resolves to a commit.

git index-pack pack-123.pack

# Create index for an existing pack.

git verify-pack -v .git/objects/pack/pack-123.idx

# Examine packed object storage.

printf "%s
" <object_sha> | git pack-objects out/pack

# Create a pack from listed objects.

git unpack-objects < pack-123.pack

# Inflate objects from a pack stream.