create a new directory, open it and perform a 
            git init
            to create a new git repository.
        
            create a working copy of a local repository by running the command
            git clone /path/to/repository
            when using a remote server, your command will be
            git clone username@host:/path/to/repository
        
            your local repository consists of three "trees" maintained by git.
            the first one is your Working Directory which holds the actual files.
            the second one is the Index which acts as a staging area and
            finally the HEAD which points to the last commit you've made.
        
    
            You can propose changes (add it to the Index) using
            git add <filename>
            git add *
            This is the first step in the basic git workflow. To actually commit these changes use
            git commit -m "Commit message"
            Now the file is committed to the HEAD, but not in your remote repository yet.
        
            Your changes are now in the HEAD of your local working copy. To send those changes to your remote repository, execute 
            git push origin master
            Change master to whatever branch you want to push your changes to.
            
            If you have not cloned an existing repository and want to connect your repository to a remote server, you need to add it with
            git remote add origin <server>
            Now you are able to push your changes to the selected remote server
        
Branches are used to develop features isolated from each other. The master branch is the "default" branch when you create a repository. Use other branches for development and merge them back to the master branch upon completion.
        
            create a new branch named "feature_x" and switch to it using
            git checkout -b feature_x
            switch back to master
            git checkout master
            and delete the branch again
            git branch -d feature_x
            a branch is not available to others unless you push the branch to your remote repository
            git push origin <branch>
        
            to update your local repository to the newest commit, execute 
            git pull
            in your working directory to fetch and merge remote changes.
            to merge another branch into your active branch (e.g. master), use
            git merge <branch>
            in both cases git tries to auto-merge changes. Unfortunately, this is not always possible and results in conflicts.
            You are responsible to merge those conflicts
            manually by editing the files shown by git. After changing, you need to mark them as merged with
            git add <filename>
            before merging changes, you can also preview them by using
            git diff <source_branch> <target_branch>
        
            it's recommended to create tags for software releases. this is a known concept, which also exists in SVN. You can create a new tag named 1.0.0 by executing
            git tag 1.0.0 1b2e1d63ff
            the 1b2e1d63ff stands for the first 10 characters of the commit id you want to reference with your tag. You can get the commit id by looking at the... 
        
            in its simplest form, you can study repository history using..
            git log
            You can add a lot of parameters to make the log look like what you want. To see only the commits of a certain author:
            git log --author=bob
            To see a very compressed log where each commit is one line:
            git log --pretty=oneline
            Or maybe you want to see an ASCII art tree of all the branches, decorated with the names of tags and branches: 
            git log --graph --oneline --decorate --all
            See only which files have changed: 
            git log --name-status
            These are just a few of the possible parameters you can use. For more, see 
            git log --help
        
            In case you did something wrong, which for sure never happens ;), you can replace local changes using the command
            git checkout -- <filename>
            this replaces the changes in your working tree with the last content in HEAD. Changes already added to the index, as well as new files, will be kept.
        
            If you instead want to drop all your local changes and commits, fetch the latest history from the server and point your local master branch at it like this
            git fetch origin
            git reset --hard origin/master
        
            built-in git GUI
            gitk
            use colorful git output
            git config color.ui true
            show log on just one line per commit
            git config format.pretty oneline
            use interactive adding
            git add -i
        
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