Tools Section - Git

What is it?#

Git is a distributed version control software developed in C language, commonly used version management tools include GIT, SVN, etc.
Source code repository: https://git.kernel.org/pub/scm/git/git.git

What can it do?#

Local Version Management#

View logs git reflog
Reset version git reset
Branch management
- Create branch git branch
- Switch branch git checkout
- Merge branch git merge

Remote Interaction Association#

Pull source code git clone <git project address>
Associate with remote repository for interaction
- Add remote repository git remote add <alias> <address>
- Upload code git push <repository alias> <branch name>
- Download code git pull <repository alias> <branch name>
- Branch association git branch --set-upstream-to=<remote repository name>/master master

How to use?#

Installation and Configuration#

Download and install the git client
Set git user information

git config --global user.name "wuxiangjun"
git config --global user.email "wuxiangjun1998@gmail.com"
# Check if configured successfully
git config --list

Generate git key

By default in the .ssh directory under the user directory

ssh-keygen -t rsa -C "your email address"

Tip

Later, if you need to upload or modify the remote repository, you need to configure the public key on the remote repository server, while keeping the private key on your local client for Git verification.

Basic Local Usage#

Note

Basic concepts:

Working directory: The actual file location on your hard drive, added to the staging area through add;
Staging area: Before truly confirming a commit, files need to be saved to the staging area, and then confirmed before committing to the local repository;
Local repository: The .git folder generated after git init.

Create Local Repository and Main Branch#

git init: Generate a local repository in the current directory and create a master branch by default
git status: Check the status of files in the current git repository

Commit to Staging Area and Local Repository#

git add .: Add all untracked files in the current directory to the staging area
git commit -m "commit message": Commit the files in the staging area to the local repository
git commit -am: Staging + committing

Version Reset#

git log: View commit records, but can only see logs before the current version
git reflog: View all commit records, including those after the current version. 【HEAD marker indicates the current version】
git reset --hard HEAD^/record number: Revert files to the state of a certain version【HEAD^ indicates the previous version】

Branch Management#

git branch <new branch name> <commit hash>: Adding a branch name indicates creating a branch, omitting it shows all current branches
git switch/checkout (old) <branch name>: Switch branches
git merge <branch name>: Merge branches, switch to the branch you want to modify first, then merge other branches

Associated Interaction Usage#

Important

Basic concepts:

Usually in a company, a git server is set up using gitlab to store source code;
You need to communicate with the administrator to obtain account permissions, which may require providing a public key or assigning an account;
Gitee and GitHub: are open-source code hosting platforms, equivalent to a remote repository.

Create and Associate Remote Repository#

Use Github or Gitee to create a repository
Add the generated public key to the remote repository
Test:
- ssh -T git@github.com
- nslookup github.com

Warning

A note:

Using ssh -T git@github.com passes normal verification, but cannot git clone normally;
Prompt ssh: Could not resolve hostname github.com: Non-recoverable failure in name resolution;
After a day of troubleshooting, powershell resolves DNS normally, but git bash cannot be used properly, hence the addition of nslookup github.com command for testing;
Temporary solution: Use powershell for git command operations.

git remote add <repository alias> git project address: Add a remote repository and give it a name

Tip

Before adding an alias, you can check the already configured remote repositories and their corresponding URLs in the project. If you find that the name is already configured, you can modify or delete it as needed.

git remote -v: View currently associated repositories
git remote rename origin new-origin: Modify remote repository alias
git remote set-url origin <new_path>: Reset repository address
git remote remove origin: Delete repository

Pull Source Code#

git clone git project address
git pull repository alias branch name: pull is actually a combination of fetch and merge

Upload Source Code#

git push repository alias branch name: Upload a certain branch of the local repository to the associated remote repository
git push -u origin main:main: Push the local main branch to the remote repository origin, and set the local main branch to track the remote main branch (i.e., upstream branch)
git branch --set-upstream-to=<repository alias>/master master: Similarly, bind the default push pull remote repository <repository alias>/master to the local master, so you can omit entering the repository name and branch name afterwards.

Supplementary Knowledge#

Overview of Git Workflow - Gitflow Workflow