Git basic # 01

Git Object Types

• Blob 

• Tree

• Commit

• Annotated tag

Blob

Blob stores any files with any extensions like .txt, .html, .css, .png, .mp4 etc

Blob represents the single file in the git structure.

Tree

The tree represents the folder or directory in git.

Commit

Commit can store the different versions of the project.

Annotated tag

Annotated tag provides the persistent pointer to the commit.  

The format of the git database is similar to JSON.

Hash function

• One-way function

• The same hash function will generate the same hash for the same input.

Create a git hash object from the text(no file exists)

Open a terminal with git directory → type …

echo “Hello, Git” | git hash-object --stdin -w

Create a git hash object from an existing file

Open a terminal with git directory → type …

git hash-object <file path> -w

Example:

git hash-object ../test.txt -w

git cat-file options

git cat-file -p <hash>  Contents of the object

Example:

git cat-file -p b7aec520dec0a7516c18eb4c68b64ae1eb9b5a5e

Result: Hello, Git

git cat-file -t <hash> type of the object

Example:

git cat-file -t b7aec520dec0a7516c18eb4c68b64ae1eb9b5a5e

Result: blob

git cat-file -s <hash> size of the object

Example: 

git cat-file -s b7aec520dec0a7516c18eb4c68b64ae1eb9b5a5e

Result: 11

Origin

The default name of the remote git repository is the origin.