notes of git course on data camp：https://app.datacamp.com/learn/courses/introduction-to-git
https://rogerdudler.github.io/git-guide/
https://git-scm.com/book/en/v2
Git has three main states that your files can reside in: modified, staged, and committed:
- Modified: the file is changed but not committed to your database yet.
- Staged: you have marked a modified file in its current version to go into your next commit snapshot.
- Committed: the data is safely stored in your local database.
git diff: compares the working directory (Modified) with the staging area (Staged).
git diff --staged: compares your staged changes to your last commit.
git commit -a -m 'Add new benchmarks': commit without adding files to the staging area.
git rm <file>: remove the file from the working directory. You will be able to commit this change. If you run rm <file>, the change is not added to the staging area.
git rm -f <file>: remove the modified file or file in the staging area.
git rm --cached <file>: remove files from the staging area but keep them in the working directory (hard drive).
git mv <file1> <file2>: rename to
git log --pretty=format:"%h %s" --graph: show commit history.
git log -S <function_name>: show commits that changed <function_name>.
git log -- <path/to/file>: show commits that changed the file.
git commit --amend: commit files in the staging area and overwrite the last commit message.
Only amend commits that are still local and have not been pushed somewhere.
git reset HEAD <file_name>: discard changes added to the staging area.
git restore --staged <file_name>: discard changes added to the staging area with git >= 2.23.0
git checkout -- <file_name>: discard changes in the modified file.
git restore <file_name>: discard changes in the modified file with git >= 2.23.0.
git checkout -- <file>is a dangerous command. Any local changes you made to that file are gone — Git just replaced that file with the last staged or committed version.
Anything that is committed in Git can almost always be recovered. Even commits that were on branches that were deleted or commits that were overwritten with an --amend commit.
A repository can have multiple remotes, the default one is named
origin. It is possible that you can be working with a “remote” repository that is, in fact, on the same host you are.
git remote -v: check the remote repositories configured in the current repo.
git fetch <remote_repo>: fetch all branches from the remote branch (default is origin)
git pull: fetch the remote branch (tracked by the local branch) and merge it into the local branch.
If you want to rebase when pulling: git config --global pull.rebase "true", otherwise, it will merge if fast-forward is not possible.
git push origin <branch_name>: push commits in the local branch to the remote branch.
git remote show origin>: show information of the remote repository named origin (default).
git remote rename pb paul: rename remote repo pb to paul.
git tag -a v1.4 -m "my version 1.4": create an annotated tag.
git show v1.4: show tag information.
git tag v1.4-lw: create a light-weighted tag.
git tag -a v1.2 <hash_tag>: use commit with hash_tag to create tag.
git push origin <tag_name>: push tag to remote repo.
git push origin --tags: push all tags to the remote repo.
$ git config --global alias.co checkout
$ git config --global alias.br branch
$ git config --global alias.ci commit
$ git config --global alias.st status
data stored in a git repository:
- blobs: stores the current version of each file when they are added to the staging area
- tree object: stores the directory information when changes are committed
- commit object: metadata and pointer to the root project tree.
The next commit stores a pointer to the commit that came immediately before it. A branch in Git is simply a lightweight movable pointer to one of these commits.
HEAD: (branch pointer) a special pointer to determine which branch you are currently on.
git branch <branch_name>: create a new branch.
git log --oneline --decorate: check which branch HEAD is pointed.
git log will only show commit history below the branch you’ve checked out. To show all branches, use:
git log --all
git checkout <branch_name>: switch to branch.
A branch in Git is a simple file that contains the 40-character SHA-1 checksum of the commit it points to.
- fast-forward merge
- three-way merge
- merge commit: this is created in a three-way merge.
git branch -v: see the last commit in each branch.
git branch --merged
git branch --no-merged
git branch --move bad-branch-name corrected-branch-name: rename branch locally.
git push --set-upstream origin corrected-branch-name: push renamed branch to remotes.
git push origin --delete bad-branch-name: delete the remote branch with the old name.
- long-running branch: You can have several branches that are always open and that you use for different stages of your development cycle.
- topic branch: a short-lived branch that you create and use for a particular feature or related work.