Git Version Control: Installation, Configuration, Core Commands, Branch & Tag Management, and Code Export

1. Install Git Version Control System

Git's working directory, staging area, and repository meanings

Working directory: the visible folder on your computer.

Staging area: also called stage or index, stored in .git/index.

Repository: the hidden .git folder that holds all history.

Installation and configuration commands:

yum install git -y<br/>git --version<br/>git config --global user.name "chenkang"   # set user name<br/>git config --global user.email "[email protected]"   # set email<br/>git config --global color.ui "true"

Initialize a repository: git init Add files and commit: git add .<br/>git commit -m 'add three file' Rename a file and commit: git mv file1 file4<br/>git commit -m 'change file name' File comparison:

git diff file3               # working tree vs. staging<br/>git diff --cached file3      # staging vs. repository

Reverting changes:

# revert a staged file<br/>git reset HEAD file3<br/># revert an unstaged file<br/>git checkout -- file3

Branch management:

# create a new branch<br/>git branch dev01<br/># switch to it<br/>git checkout dev01<br/># merge master into dev01<br/>git merge master -m 'merge master into dev01'<br/># switch back to master and merge dev01<br/>git checkout master<br/>git merge dev01 -m 'merge dev01 into master'

Branching principles:

master should be stable and used only for releases.

development occurs on dev (or feature) branches.

individual developers work on personal branches and merge into dev.

use --no-ff for a true merge commit to preserve history.

3. Git Tag Management

Tags give commits a readable alias.

# create a lightweight tag<br/>git tag v1.2<br/># delete a tag<br/>git tag -d v1.2<br/># create an annotated tag<br/>git tag -a v1.0 -m 'optimized and bug‑fixed' a119962<br/># show tag details<br/>git show v1.1

4. Exporting Code with Git Archive

Archive a branch:

git archive --format tar.gz --output "./output.tar.gz" master

Archive a specific commit or directory:

# archive a different branch<br/>git archive --format tar.gz --output "./output.tar.gz" dev01<br/># archive a specific commit<br/>git archive --format tar.gz --output "./output.tar.gz" 5ca16ac0d603603<br/># archive selected directories from master<br/>git archive --format tar.gz --output "./output.tar.gz" master <name1> <name2>

5. Upgrading Git on CentOS

Steps to replace the old Git version (1.8.x) with a newer one (2.23.0):

# install build dependencies<br/>yum install curl-devel expat-devel gettext-devel openssl-devel zlib-devel asciidoc -y<br/>yum install gcc perl-ExtUtils-MakeMaker -y<br/># remove old Git<br/>yum remove git -y<br/># download source tarball<br/>wget https://mirrors.edge.kernel.org/pub/software/scm/git/git-2.23.0.tar.xz<br/># extract and build<br/>tar xf git-2.23.0.tar.xz<br/>cd git-2.23.0<br/>make prefix=/usr/local/git all<br/>make prefix=/usr/local/git install<br/># add new Git to PATH
echo "export PATH=$PATH:/usr/local/git/bin" >> /etc/profile