At least two ways to install this tool:

First:
    1. Copy the whole directory somewhere you can access
        # cp -r shadow-git /usr/local/shadow-git

    2. Add /usr/local/shadow-git to your PATH
        # echo "PATH=/usr/local/shadow-git:$PATH" >> ~/.bashrc

Second:
    Copy all shadow-git-* files and the lib.py to your PATH.

        # cp shadow-git-* lib.py /usr/local/bin



How to use?

    1. first you need a git repository, or create one
        # git init

    2. ensure you had set your identity
        # git config user.name
        # git config user.email

    3. in the git repository directory
        # git shadow-init

    4. when you want to push to the server, run a command like the following,
       it will create a new branch named like 'cipher-origin-master' in the
       local repo, and push this 'cipher-origin-master' to the remote, but
       the name of the branch on the remote will be 'cipher-master'.
        # git shadow-push origin master

    5. fetch from the server. This command will fetch data from the remote and
       create a temporary branch named 'plain-origin-master' in the local repo
       for laster merge.
        # git shadow-fetch origin master

    6. merge the data just fetched from the remote. In caese of any conflict,
       it will stop and inform you, just solve any conflict as usual, and run
       the command again. The temporary branch plain-origin-master will be
       deleted after successfully merged.
        # git shadow-merge plain-origin-master

    7. manage the public keys of the team
        # git shadow-pubkey list
        # git shadow-pubkey add
        # git shadow-pubkey remove <keyword>

    8. when a new team member comes in.
        8.1 do this on an old member's computer:
            # git shadow-symkey update
            # git shadow-symkey push origin
        8.2 do this on the new member's computer, it will clone the repo,
            setup shadow git, and decrypt the cipher branches.
            # git shadow-clone <repository>