Common Git Commands and Their Usage

Git's four main components are introduced, followed by a detailed list of commonly used commands.

1. Initialize a repository: git init 2. Add files to the staging area:

git add filename            # add a specific file
git add -u                 # add modified or deleted tracked files
git add -A                 # add all changes, including untracked files
git add .                  # add all files in the current directory
git add -i                 # interactive mode

3. Commit staged changes to the local repository:

git commit -m "commit message"   # normal commit
git commit -a -m "msg"           # skip staging, commit all modified files

4. Check repository status: git status 5. Compare differences:

git diff                         # working tree vs. index
git diff branchname              # working tree vs. a branch
git diff HEAD                    # working tree vs. last commit
git diff commitID filePath       # specific file vs. a past version
git diff --stage                 # index vs. last commit
git diff tag                     # changes since a tag
git diff branchA branchB         # compare two branches
# add --stat to see file change statistics

6. View commit history:

git log                         # list commits
git log -p -n <number>          # show patches for recent commits
git log --stat                  # summary of changes per commit
git log --name-only             # list changed files only
git log --name-status           # list added/modified/deleted files
git log --oneline               # compact one‑line per commit
git log --graph --all --oneline # graphical branch history
git log --author="name"        # filter by author
git log --grep="text"          # filter by commit message
git log -S"text"               # search for added/removed text
git log filename                # history of a specific file

7. Roll back changes:

git reset HEAD^                 # undo last commit
git reset HEAD^^                # undo two commits
git reflog                     # view reference log
git reset --hard <commitID>    # reset to a specific commit (hard)
# reset options: --soft (move HEAD only), --mixed (reset index), --hard (reset working tree)

8. Push to remote repository: git push -u origin master 9. Delete a file from the repository: git rm filename 10. Replace working‑tree files with a version from the repository: git checkout -- test.txt 11. Add a remote origin:

git remote add origin [email protected]:username/repo.git

12. Clone a remote repository: git clone [email protected]:username/repo.git 13. Create and switch to a new branch:

git checkout -b dev   # creates and checks out 'dev'
# equivalent to:
git branch dev
git checkout dev

14. List branches: git branch 15. Merge a branch:

git merge dev                     # merge 'dev' into current branch
git merge --no-ff -m "merge with no-ff" dev   # create a merge commit even when fast‑forward is possible

16. Delete a branch: git branch -d dev 17. Visualize branch history:

git log --graph --pretty=oneline --abbrev-commit

18. Show remote information:

git remote          # list remotes
git remote -v       # detailed URLs

19. Configure Git settings:

# Set user identity globally
git config --global user.name "Your Name"
git config --global user.email "[email protected]"
# Verify configuration
git config --global user.name
git config --global user.email
# List configurations
git config --global --list
git config --local --list
git config --system --list
git config --list
# Enable colored output
git config --global color.ui true

20. Revert a specific commit:

git revert HEAD               # revert the latest commit
git revert <commitID>         # revert a specific commit

21. Pull a remote branch to local:

git checkout -b localBranch remoteBranch   # create and switch to a new local branch tracking remote
git fetch origin remote:local               # fetch without checkout
git branch --set-upstream-to=origin/remote localBranch   # set upstream tracking

22. Tag operations:

git tag <tag>                # create tag at HEAD
git tag                     # list tags
git tag <tag> <commitID>    # tag a specific commit
git show <tag>              # display tag details

23. Synchronize updates from remote:

git fetch origin master    # fetch latest from remote master
# compare and merge as needed; fetch is safer than pull

Additional promotional section about a Java content creator follows, which is not part of the technical guide.