Git

Sat, 01 Jul 2023 00:00:00 +0000

Introduction

Git is a famous and powerful open-source software for version control and management. It was developed by Linus Torvalds with C programing language. What is different from subversion, git adopts a completely distributed manner. Regarding its utilization, besides its built-in manual, there is also an excellent book, Pro Git, which can be obtained for free¹. This post just summarizes the preliminary usage of git, which is referred from the book.

Objects

In git, there are 3 types of objects defined, blob, tree, and commit. In order to view its properties, a dedicated command git cat-file is provided. Its type and content can be returned with option -t and -p respectively.

A blob keeps the content of a binary compressed file.
A tree represents a directory, including its hierarchy, permission, and the names of its componential files.
A commit is essentially a SHA-1 hash.

A branch or a tag is nothing but a pointer pointing at the SHA-1 hash of a commit. Moreover, HEAD is also a pointer, which always points the active branch at the time.

Areas

In the utilization of git, there are four important areas for storage, workspace, index (or stage), repository and remote. Their relationship can be illustrated by the figure below.

Git on Shaka

Git

Introduction

Objects

Areas