Introduction to git (notes)

A step by step introduction to git. Also, see reference1 and reference2

Install git

• Download and install git: https://git-scm.com/ or https://npm.taobao.org/mirrors/git-for-windows/

Create ssh key pairs

• Create ssh key pairs: $ ssh-keygen -t ed25519 -C "your_email@example.com"
• Copy information of id_ed25519.pub into SSH keys at your github page

Clone a repository from github to a local directory

• $ git clone https://github.com/xxxxxxx/xxxxxxxx.git

Add files, make changes, pull, push, etc.

• Create new file in your repository: $ touch aFile.md
  • Also, if the file aFile.md already exists, you can edit it then excute the following steps
• Restore changes in file (should be used before ‘git add .’): $ git restore aFile.md
• Then the file “aFile.md” is Untracked, we can check it by: $ git status
• Next, we can make it staged by: $ git add .
• After that, we commit the change to the local repository by: $ git commit -m "aFile.md is added"
• Finally, we push the change to the onCloud repository by: $ git push origin master
• If changes have been made onCloud, Pull changes from the onCloud repository by: $ git pull
  • This is equal to $ git fetch + git merge

Branch

• See local branches: $ git branch
• See remote/onCloud branches: $ git branch -r
• Create a new branch but stay at the old branch: $ git branch newBranch
• Create a new branch and changed to the new branch: $ git checkout -b newBranch
• Switch a branch: $ git switch newBranch
• Merge a specified branch (sBranch) to the present branch: $ git merge sBranch
• Delete a branch: $ git branch -d branchName
• Delete a remote branch:
  • $ git push origin --delete branchName
  • $ git branch -dr [remote/branch]
• Branch conflict
  • If a file is both updated, commited in different branches, e.g., master and dev, and dev is merged into master, then branch conflict will appear.
  • Thus we need to solve the conflict manully: either by artifically modify the target file in master branch, or just click a choice in the opened vscode window.
  • Finally, add, commit and push the updated master branch. And delete the dev branch if necessary.
• If the branch dev is onCloud, we can clone/switch locally by: $ git branch dev remotes/origin/dev
• Check the fetch and push urls: $ git remote -v
• After edit and commit, update the local dev to onCloud dev by: $ git push origin dev

Version tag control

• Use git tag use check the current version: $ git tag
• After commit, use git tag use update the new version: $ git tag v1.3.99
• Recheck the version by git tag
• See the detailed change in each version: $ git show v1.3.99

Use alias (optional)

• Change name of git xxxx command by a short one as: $ git config --global alias.[shortName] [commandName]
• For example (git st = git status): $ git config --global alias.st status

Connection errors

• Failed to connect to github.com port 443 after 21098 ms: Timed out
  • $ git config –global –unset http.proxy
  • $ git config –global –unset https.proxy
• OpenSSL SSL_read: Connection was reset, errno 10054
  • $ git config –global http.sslVerify “false”