git_introduction.md

Introduction to git

git is a Version Control System

• A Version Control System is a software that tracks the file changes of all contributors within a project.
• Originally developed to assist collaborative open source software development by Linus Torvalds (Initiator of Linux development)
• The user chooses which files are tracked and which file changes are recorded.
• All tracked files of a project are stored in a git repository ("repo").

git tracks file changes through commits

Each line is a commit, a saved state of your project. Each commit has a creator, a time stamp and a message which describes what has been changed in the files of the project.

git status shows the current state of the repository

$ git status

A commit records file changes within the repository

Adding files to the staging area, which will be included in the next commit.

$ git add ham.py
$ git add spam.txt

Creating the commit containing the files in the staging area:

$ git commit -m "edited ham.py, created spam.txt"

git needs to know who is creating the commit

Registering your user name and email:

$ git config --global user.name "Alfred Hettner"
$ git config --global user.email "[email protected]"

Note: This has to be done only once. It does not have to be your GitHub user name or email.

git log shows all commits of this repository

$ git log

Note: You can exit the log by typing "q", if you use the default command line editor vim.

Synchronizing your local commits with a central git repository

Connecting a local repository to a central repository

Option 1: Clone the repository to your computer:

$ git clone https://github.com/geoscripting/preparatory-assignment-hettner

Option 2: Create a local repository and connect it to a central repository:

$ git init
$ git remote add origin https://github.com/hettner/my_empty_repo.git

Resources

The Software Carpentry provides a good git tutorial.