Using GitHub to Develop Software Collaboratively

這是兩年前 GitHub 來成大教育課程的筆記
最近在整理 git 的筆記才翻出來
因為當時是以英文進行，課程筆記就也用英文做了
這篇的內容可能比較雜亂，之後還會再整理進另一篇 git 的筆記

Introduction to Git Hub (Company)

There are around 2600 staffs in GitHub and 40% of them live in San Fransisco.
Among them, there is one Taiwanese.

Git

Wrote by Linus Torvalds.

Why version control?

1. Historical propose
2. Collaboration

Tutorial

git init "path"

.git is just a folder with normal file
There is no daemon or background progress
Everything is operated in file
Never rm -rf .git XD

git status
touch README.mdd

There are three main stages

1. working
2. staging
3. repo

git add README.md

When we're ready
git commit -m "add a blank commit"

After README.md is modified

git add README.md
git status

Now this file is in staging area

So, how to go back to history?
git reset README.md

Take a look at our history
git log

Go back to history
git checkout "SHA1"

git checkout master
Everything comes back

master is the default branch name of git. It is a default word but not reserved.

git checkout -b "branch_name" create a branch and checkout to it

diff

git diff: View the difference between working and staging

git diff --staged: Difference between staging and repo

git diff "SHA1": Difference between current version and SHA1

git diff master~1: difference between current and the one before master
git diff master^ → master~1
git diff master^^ → master~2

git diff a b: Show the change from a to b

branch

In git, branch is not copy. It's like bookmark
Actually git branch -d "name" just delete the pointer but not the entry.

HEAD: the pointer points to current entry

detach error

If you go back to a entry not in certain branch, a detach error might occur.
For example, checkout to a commit that is parent of more than one branch and then append a new commit to it.
In such case, this new appended commit might not be able to be referenced.
The solution to this problem is to create a new branch for it.

log

git log --decorate: Show also branch info

git log --all: Show all branch

git log --graph: Show graph

The difference between log and show

git log: Only the first line
git show: All the message, not only the first line

GitHub

push

origin is a short hand name of that remote url. In other word, your repo.

git push -u origin master

• upload master to origin
  8 -u tell git the default url to push for that branch(master) is origin, it would also make git pull remember
  • Do -u and after that you can just use git push

pull

git push --all: push all branch
git pull --prune

difference between fetch and pull

git fetch : go to remote and copy it
git pull → fetch + merge

on-site

pull request on GitHub
@person-name → notification
Have a conversation with the whole team

Write "fix #2 ...." in git commit → special meaning → specify the bug in issue on GitHub
Wiki → documentation

How to write a good git commit

Principle

• Separate each commit
• Let the commit tell a story

More specific

• One line 80 character
• Use present tense instead of past tense
• Don't repeat what can be found in git diff
• If more detail is to be written, left the second line to be blank.
• Write more detail about why this change happened after the third line.

Other issue

git config --global -e: Edit your .gitconfig file.

Not include binary files and executable
Don't version control these kinds of files.
Also, large files are not recommended to add to git.
If it's needed, try git-annex(web-site).

git revert "SHA1" → save another entry of undo

If you commit the password → git rebase can change commit, but it is not that recommended.

git submodule create a sub-module