git cat-file to inspect objects - Commands & Configuration

Introduction

Sometimes you want to look inside the hidden parts of your Git project to see exactly what is stored. The git cat-file command lets you peek inside Git objects like commits, trees, and blobs to understand what data they hold.

When you want to see the content of a specific commit or file version stored in Git.

When you need to check the exact data stored in a Git object by its hash.

When debugging Git issues by inspecting low-level objects.

When learning how Git stores data internally by viewing raw object contents.

When verifying that a commit or blob contains the expected information.

Commands

Create a new Git repository named example-repo to start tracking files.

Terminal

git init example-repo

Expected Output

Initialized empty Git repository in /current/path/example-repo/.git/

Change directory into the new repository to work inside it.

Terminal

cd example-repo

Expected Output

No output (command runs silently)

Create a file named file.txt with the text 'Hello Git' inside.

Terminal

echo "Hello Git" > file.txt

Expected Output

No output (command runs silently)

Tell Git to track the new file.txt by adding it to the staging area.

Terminal

git add file.txt

Expected Output

No output (command runs silently)

Save the staged file.txt to the repository with a message describing the change.

Terminal

git commit -m "Add file.txt with greeting"

Expected Output

[master (root-commit) abcdef1] Add file.txt with greeting

 1 file changed, 1 insertion(+)

 create mode 100644 file.txt

→

-m - Provide a commit message inline

Get the hash ID of the latest commit to use it for inspection.

Terminal

git rev-parse HEAD

Expected Output

abcdef1234567890abcdef1234567890abcdef12

Show the full content of the commit object identified by the hash. This reveals commit details like tree, parent, author, and message.

Terminal

git cat-file -p abcdef1234567890abcdef1234567890abcdef12

Expected Output

tree 1234567890abcdef1234567890abcdef12345678

author Your Name <[e-mail]> 1686000000 +0000

committer Your Name <[e-mail]> 1686000000 +0000



Add file.txt with greeting

→

-p - Pretty-print the object content in a human-readable form

Show the type of the Git object (commit, tree, blob, tag) for the given hash.

Terminal

git cat-file -t abcdef1234567890abcdef1234567890abcdef12

Expected Output

commit

→

-t - Show the object type

Key Concept

If you remember nothing else from this pattern, remember: git cat-file lets you look inside Git objects by their hash to see their type and content.

Common Mistakes

Using git cat-file without a valid object hash

Git cannot find the object and returns an error because the hash is missing or incorrect.

Always use a full or abbreviated valid object hash from git rev-parse or git log.

Not using the -p flag when wanting readable content

Git outputs raw binary or unreadable data which is hard to understand.

Use git cat-file -p to pretty-print the object content in a readable format.

Summary

Initialize a Git repository and commit a file to create objects.

Use git rev-parse HEAD to get the latest commit hash.

Use git cat-file -p <hash> to view the content of a Git object.

Use git cat-file -t <hash> to see the type of the object.