Git basics - simply explained

This blog entry gives a quick insight into Git basics, is aimed at beginners and is intended to make working and getting started easier. The very first steps are shown, the most important functions are presented, the advantages and disadvantages are considered and a comparison to SVN is made. For advanced users, further entries will follow, covering various focal points, advanced functions and graphical GUI clients.

What is Git

Git is a distributed versioning system for managing files. Non-linear development and decentralized storage are typical of Git. Although there is a central repository, each user has a local copy including the corresponding versions, which also represent a backup (distributed system). A continuous connection to the remote repository is therefore not absolutely necessary, only for synchronization. In addition, Git is platform-independent and can therefore be set up in almost any environment.

First steps and most important functions

Git comes "out of the box" with a command line, without a GUI. For some, this is a great thing, others prefer to work with one of the many graphical interfaces or use plug-ins that are available for various editors. One advantage of the command line in contrast to all the GUI alternatives is that all existing Git commands can be executed. The first and most important steps after installation are as follows:

The (basic) configuration

git config -1	Show configuration
Git config -global user.name "Max Mustermann"	Set up user (displayed in every commit)
git config -global user.email "max.mustermann@in-factory.com"	Set up e-mail
git config user.name	Query individual configuration
git config -global init.defaultBranch main	Configure branch name "main

 

Create/clone the repository

git init	initialize a new repository (you must be in the respective directory for this)
git status	Query status in the repository
git clone /directory/repository	creates a local copy of a repository
git clone username@host:/directory/repository	creates a local copy of a remote repository

 

The workflow

"Git defines three main states in which a file can be: committed, modified and staged.

Modified means that a file has been changed but not yet checked into the local database.

Staged means that a changed file is marked for the next commit in its current state.

Committed means that the data is securely stored in the local database." (see Scott Chacon & Ben Straub, Pro Git (Second Edition)¹, 2021, p. 17)

 

Add & Commit

git add	Add file (staging)
git add *	Add all files in the directory (staging)
git commit	Commit "saves" the new version (affects the local repository, not the remote one)
git commit -m "Message Text"	Commit "saves" the new version with comment
git log	List commits
git reset	Undo action

 

Upload the changes

git push origin	Send changes in the local repository to the remote repository
git remote add origin	Upload created repository

 

Branching

Branches, a major difference to SVN, are used to isolate different developments from each other. The master or main branch is the main branch of each repository. Other branches should be used during development, which are then merged with the master or main branch at a later stage.

git checkout -b	creates new branch
git checkout master	Switch branch to master branch
git branch -d	Delete branch
git push origin	Upload branch to remote repository (make available to others)

 

Update & Merge

git pull	Pull the latest version from the remote repository into the local repository
git merge	Merge a branch with the current repository
git diff	Show differences between two branches

 

Tagging

git tag 1.0.0	Create a new tag (release tags as known from SVN, for example, the Commit_Id is referenced with the tag)
git log	Show commit list

 

Undo change

git checkout -	Reset locally changed status to the checked-in status
Git fetch origin Git reset -hard origin/master	Discard local version and retrieve status from remote repository
git revert	Undo commit

 

Lifecycle status of a file in Git

Advantages

• Parallel working (decentralized, branching)
• Protection through distributed repository
• Flexibility through different working methods
• Offline work possible due to decentralized and linkable structure
• Extensibility (various web clients and plug-ins)
• Free of charge

Disadvantages and criticism

One major point of criticism is that it is not so easy to learn. For beginners, some of the terminology is new and users of other systems are sometimes confused, e.g. "-revert" means something different in SVN than in Git.

If, for example, you want to completely record the structures of empty directories for some reason, Git is not suitable. If the directories have no content, Git discards them.

Comparison with SVN

Whether Git or SVN, they are probably the two best known of their kind and both have their respective advantages and disadvantages. Here are the most relevant differences:

	Git	SVN
Version management	distributed	central
Repository	Local repository copies in which development takes place	Central repository in which work progress is created
Connection with network	Only required for synchronization	with every access
Authorization/access	entire directory	path-based
Changes	records content	records files
Traceability/history	Repository and local copies contain complete history	only complete in the repository, local copies only contain the latest version

The book can be downloaded free of charge here