Using Git

Installing Git

homebrew http://brew.sh/

git config --global user.name 'chuhemiao'

git config --global user.email '[email protected]'

Creating a Repository

Create a directory and let Git manage it.

mkdir gitrepository

git init

Git creates the hidden .git directory.

Adding Files

1. Create a file:

touch README.md

vim READEME.md

Welcome to git world!!!

git status / git status -s

git add READEME.md

git commit -m 'add a reademe file'

2. Modify a file using the same workflow.

Use git diff filename to inspect changes. git diff HEAD -- readme.txt compares the working tree with the latest committed version.

Rolling Back

git reset HEAD filename

Use --hard carefully.

git reset --hard HEAD^ returns to the previous version.

git reset --hard HEAD~n returns n versions back and fails if that version does not exist.

git reset --hard commitid returns to a specified commit.

git revert commitid

After one commit and two subsequent modifications, inspect the commit history with:

git log --pretty=oneline

git reflog records operations and helps recover commit IDs so you can choose a version to return to.

Working Tree and Staging Area

1. The working tree is the gitrepository directory we created.
2. The staging area is part of the repository represented by the .git directory generated by git init.

The .git directory contains:

• The stage, or staging area.
• The first branch Git creates, master.
• HEAD, a pointer to master.

git add filename adds a file's working-tree changes to the stage.

git commit commits the staged content to the current branch, here master.

Managing Changes

After a modification, use git add ,git commit to record it.

Discarding Changes

git checkout -- README.md discards working-tree changes to README.md.

If the changes have not been staged, the file returns to its repository state.

git reset HEAD README.md unstages changes and puts them back in the working tree.

If the file was staged and then changed again, checkout returns it to its staged state.

If it has already been committed with git commit, use version rollback.

In short, the file returns to its state at the latest git commit or git add.

Deleting Files

rm README.md

git rm README.md

If you only used git add and have not committed, these notes treat git rm -f README.md as unrecoverable. A file removed with rm README.md can be restored with git checkout -- README.md.

Restore staged content:

git reset HEAD README.md

git checkout -- README.md

The file is restored.

Adding a Remote

git remote add origin https://github.com/chuhemiao/baqiye.git

git push -u origin master

git pull fetches the latest code from the remote.

git clone clones code from the remote.