<img class="plain" style="padding-right: 20px" data-src="media/uni_logo.png" alt="Uni Stuttgart Logo" height="70px"> <img class="plain" data-src="media/crc1313.png" alt="SFB Logo" height="70px"> # Introduction to git 11th July 2018 @ LH2 Timo Koch, Bernd Flemisch

I quickly commented out a bit of code and forgot it 🙈

I have a lot of local versions of files, no idea which change is where 🙉

My stuff doesn't do the same as last week 🙊

Someone else changed my stuff and I have no idea where 😤

➡ Use version control!

we follow the great git tutorial by Atlassian (bitbucket) https://www.atlassian.com/git/tutorials/setting-up-a-repository <iframe src="https://www.atlassian.com/git/tutorials/setting-up-a-repository" height="400px" width="800px"></iframe>

<h2>Setting up your own git repository</h2> <p style="font-size: 150%"> git init </p> <p style="font-size: 150%"> git config </p> <p style="font-size: 150%"> .gitignore </p> <p style="font-size: 150%"> git clone </p>

<p style="font-size: 200%"> git init </p> ``` git init ```

<p style="font-size: 200%"> git config </p> ``` git config --global user.name "Timo Koch" git config --global user.email "timo.koch@iws.uni-stuttgart.de" ```

<p style="font-size: 200%"> .gitignore </p> ```ini # ignore python caching files *.pyc # ignore build system clutter build-* # always consider files containing source code regardless of their name !*.cpp !*.hh !*.py ```

<p style="font-size: 200%"> git clone </p> ``` git clone https://git.iws.uni-stuttgart.de/dumux-repositories/dumux.git ``` be aware of options https/ssh (https is easier to set up) ``` git clone git@git.iws.uni-stuttgart.de:dumux-repositories/dumux.git git clone https://git.iws.uni-stuttgart.de/dumux-repositories/dumux.git ```

<h2>Keeping track of changes 1/2</h2> <p style="font-size: 150%"> git status </p> <p style="font-size: 150%"> git diff </p> <p style="font-size: 150%"> git log </p>

<p style="font-size: 200%"> git status </p> ``` git status ``` ``` On branch feature/init-twop-immiscible Your branch is up-to-date with 'origin/feature/init-twop-immiscible'. Changes to be committed: (use "git reset HEAD <file>..." to unstage) modified: README.md Changes not staged for commit: (use "git add <file>..." to update what will be committed) (use "git checkout -- <file>..." to discard changes in working directory) modified: dune.module Untracked files: (use "git add <file>..." to include in what will be committed) tutorial/gridmanager.py ```

<p style="font-size: 200%"> git diff </p> ``` git diff git diff <file/folder> git diff <commit> <commit> ... ```

<p style="font-size: 200%"> git log </p> ``` git log git log -5 git log --oneline ```

<h2>Keeping track of changes 2/2</h2> <p style="font-size: 150%"> git add </p> <p style="font-size: 150%"> git commit </p> <p style="font-size: 150%"> git stash </p>

<p style="font-size: 200%"> git add </p> ``` git add <file/folder> git add -p ```

<p style="font-size: 200%"> git commit </p> ``` git commit git commit <file/folder> git commit -m "[example] my informative but brief commit message" ```

<p style="font-size: 200%"> git stash </p> ``` git stash git stash list git stash pop git stash pop stash@{3} git stash drop git stash drop stash@{1} ```

<h2>Undoing changes</h2> <p style="font-size: 150%"> git checkout </p> <p style="font-size: 150%"> git reset </p> <p style="font-size: 150%"> git revert </p>

<p style="font-size: 200%"> git checkout </p> ``` git checkout <file/folder> git checkout -p ```

<p style="font-size: 200%"> git reset </p> ``` git reset HEAD <file/folder> git reset --soft HEAD~1 git reset --hard HEAD ```

<p style="font-size: 200%"> git revert </p> ``` git revert <commit> ``` note: this creates a new commit.

<h2>Collaborating</h2> <p style="font-size: 150%"> git remote </p> <p style="font-size: 150%"> git fetch </p> <p style="font-size: 150%"> git pull </p> <p style="font-size: 150%"> git push </p>

<p style="font-size: 200%"> git remote </p> ``` git remote add origin https://git.iws.uni-stuttgart.de/dumux-repositories/dumux.git git remote show git remote show origin git remote remove origin ```

<p style="font-size: 200%"> git fetch </p> ``` git fetch origin ```

<p style="font-size: 200%"> git pull </p> ``` git pull git pull --rebase ```

<p style="font-size: 200%"> git push </p> ``` git push git push -u origin master ```

<img class="plain" data-src="media/branches.svg" alt="branches" height="200px"> <h2>Feature branch workflow</h2> <p style="font-size: 150%"> git branch </p> <p style="font-size: 150%"> git checkout </p> <p style="font-size: 150%"> git merge </p>

<p style="font-size: 150%"> git branch </p> ``` git branch git branch -r git branch -a git branch feature/my-awesome-new-thing ```

<p style="font-size: 150%"> git checkout </p> ``` git checkout <file> git checkout <commit> git checkout <branch> git checkout -b feature/my-awesome-new-thing ```

<p style="font-size: 150%"> git merge </p> Usually, you will merge in a web frontend via pull requests (GitHub) / merge requests (GitLab). * push your changes to a branch on remote * open a merge request * someone else reviews and merges ``` git merge --no-ff feature/my-awesome-new-thing master ```

<h2>Rewriting history</h2> <p style="font-size: 150%"> git commit --amend </p> <p style="font-size: 150%"> git rebase </p> <p style="font-size: 150%"> git cherry-pick </p> <p style="font-size: 150%"> git push --force </p> <p style="font-size: 150%"> git reflog </p>

<h2>General rules</h2> * Only rewrite history, if you know you are the only one working on this! * Rewrite history to make your changes more understandable

<p style="font-size: 150%"> git commit --amend </p> ``` git commit --amend git commit --amend --author="Timo Koch <timo.koch@iws.uni-stuttgart.de>" ```

<p style="font-size: 150%"> git rebase </p> ``` git rebase git rebase -i master git rebase -i HEAD~2 ```

<p style="font-size: 150%"> git cherry-pick </p> ``` git cherry-pick <commit> git cherry-pick -x <commit> ```

<p style="font-size: 150%"> git push --force </p> ``` git push --force origin feature/my-awesome-new-thing ```

<p style="font-size: 150%"> git reflog </p> ``` git reflog ```

<img class="plain" style="padding-right: 20px" data-src="media/uni_logo.png" alt="Uni Stuttgart Logo" height="70px"> <img class="plain" data-src="media/crc1313.png" alt="SFB Logo" height="70px"> # Thank you! Questions?