Git manual

Documentation

Git official documentation - https://git-scm.com/doc

GitHub cheatsheet - https://training.github.com/kit/downloads/github-git-cheat-sheet.pdf

Downloading Git

https://git-scm.com/downloads

When installing Git on Windows operating system, installation settings can be set as default. (Use Git from Git Bash only; Checkout Windows-style, commit Unix-stile line endings; Use MinTTY)

Getting started

Each student has already a repository generated beforehand. For example:

https://git.ttu.ee/kursused/iag0581/username.git

For authentication your Uni-ID will be used. (The same username and password that you use for logging in to the lab computers).

Assuming that Git is successfully installed, in Windows open start menu and search for Git Bash and open it. In Linux or Mac simply open terminal.

Cloning

Let's say that we want to clone the repository to our local directory at C:\workspace. First we have to change the current directory by typing to terminal:

cd /c/workspace

For cloning the existing repository from https://git.ttu.ee/kursused/iag0581/username.git, type in:

git clone https://user@git.ttu.ee/kursused/iag0581/user.git iag0581

Username will be your Uni-ID, which is the same as the one you use for logging into lab computers. If you do not know your Uni-ID, go to https://pass.ttu.ee .

After you authenticate yourself by inserting your password, the repository is cloned into the local directory C:\workspace\iag0581 and we can change also our current directory to it by typing:

cd iag0581

Staging area

Next we can start adding files for version control. Let's say that we already have some files in another directory (C:\workspace\lab1) that we wish to add to version control. For copying files in terminal there is a command cp.

cp C:\workspace\lab1 C:\workspace\iag0581 -rf

To make sure that the files copied over successfully we can see the contents of the current directory by entering command ls. Next we have to notify git that we have files that we wish to add to version control. Git has so called staging area, which is used to temporarily hold, prepare and review changes to be made. To add files into the staging area, command git add <filename> is used. So if we wish to add the previously copied folder, type:

git add lab1

To see all the files in the staging area for making sure we are ready to commit the changes, there is a command git status which lists all the new and modified files to be committed.

Committing

Before committing it is required to set up your name and e-mail with git. To do that there are following commands that should be inserted:

  git config --global user.email "you@example.com"
  git config --global user.name "Your Name"

Next we can commit the changes with the command:

git commit -am "your comment about the commit"

Pushing

Now that the changes are stored locally we may want to push the changes back to remote repository also. To do that there is the command git push

git push origin master

Origin and master specify to which remote repository and branch the commit will be pushed into. Next your username and password will be asked. (The same username and password that you use for logging in to the lab computers).

Pulling

For the next scenario, let's say that we have repositories cloned locally to both lab computer and computer at home. Now when we have made changes to repository while working from lab and we want to update the local repository from home, git pull is used. Git pull incorporates changes from a remote repository into the current local branch.

git pull

Other useful (but more advanced) commands

See graphical revision history.

gitk

Checkout earlier version. Hash can be found out using gitk or git log for the corresponding version (Looks something like b22756ed3s...). It is not required to supply the whole hash, first unique characters are enough.

git checkout <hash>
git checkout b22

Undo last commit. (source: http://stackoverflow.com/questions/927358/how-do-you-undo-the-last-commit)

git reset --soft HEAD~1

For more advanced usage it is recommended to read documentations on the internet. Good places to start are Git official documentation - https://git-scm.com/doc and for quick reminders - https://training.github.com/kit/downloads/github-git-cheat-sheet.pdf .

Branching

Using branching can make managing and organizing your repository easier. It can be used for example, if you want to try out new feature without making edits to your master branch. To create a new branch, insert

git branch <branch name>

To check out newly created branch

git checkout <branch name>

For switching back to master branch

git checkout master

To see existing branches:

git branch

For deleting:

git branch -D <branch name>