2. Terms used
• VCS – Version Control System
• Check-in – Storing files in the VCS Central Repo
• Check-out – Getting files from the VCS Central Repo
• Commit – Git’s term for check-in
3. What does version control do?
• Version files
• Manage changes from multiple users
• Store the versions in a central repository
6. Multi-User Check-in
Concurrent - Different Files
Check-in
at 9 A.M.
Check-out
at 8 A.M.
Check-out
at 8 A.M.
VCS: “I
am
good”
Check-in
at 9 A.M.
7. Multi-User Check-in
Concurrent – Same Files
Check-in at
9 A.M.
Check-out
at 8 A.M.
Modified lines:
Line 5
Line 6
Holiday.py
Modified lines:
Line 10
Line 11
Holiday.py
Merge
Check-in
at 10 A.M.
Check-out
at 8:30 A.M.
8. Multi-User Check-in
Concurrent – Same Files
9 A.M.
Merge
Conflict
Line 5
Line 6
Holiday.py
Line 5
Line 6
Holiday.py
10 A.M.
Check-out
at 8 A.M.
Check-out
at 8 A.M.
12. Git – How is it different
• Repository is seen as a whole and not as files
• Commit a repo and not files
• Go back to a specific version of a repo and not a file
• Repository is local and not remote
• Entire repository can be accessed locally
• No need to be connected to the remote server
• Branches are also versions of the repo and not copies of it
• Create a new branches in the same filesystem
• Pull branches from remote server into the same filesystem
• Work on two branches simultaneously in the same file system
• Forking user repo is inherent
• Github server provides you option to fork your copy of the repo which
helps collaboration initiated from the user side
• Free github account to host experimental projects
13. Git Repository
• git init
• Creates a git local repository
• .git directory
• A hidden directory in the repository which has the repo information
like version history of all the files, branch information
• git clone <url>
• Download the remote repository at <url> and create a local
repository for it
14. Git – Working with files
• The four states for a file
• Untracked – The files that are not never added to git are in this stage
• Unmodified – Files that are in the git repo, but not edited.
• Modified – Files edited by you after getting changes from the repo
• Staged –Files that are staged for commit
• git add
• Moves untracked files / modified files to staged state
• git rm
• Move staged files to modified / untracked files
• git diff
• Show changes made to files in modified state
• git diff –cached
• Show changes made to files in staged state
• git commit
• Save changes to the local repository
• git checkout – <file>
• discard changes in working directory
• git reset
• Reset or revert to an earlier commit
• git log
• Show the commit history of the
15. Git – Working with branches
• git checkout –b
• Create a new branch and switch to it
• git branch
• List all the branches
• git merge <branch>
• Merge the current branch with the changes from <branch>
• git rebase <branch>
• Modify the development history of the current branch by pulling the
commits from it since the common latest commit <A> of the two
branches, apply the commit history of <branch> since <A> to the
latest commit to the current branch and re-apply the pulled-out
commits on top of it.
16. Git – Connecting with remotes
• User configuration
• Repo Level - .git/config
• Global Level - ~/.gitconfig
• System Level - /etc/gitconfig
• Know your git configuration
• git config
17. Git – working with remotes
• The three transfer protocols that help upload / download content from the remote
repositories
• Git
• Fastest Transfer
• No authentication
• SSH
• Authenticated Write access
• Efficient data transfer
• Encrypted data transfer
• Http
• Easy to setup
• Can serve read-only repos
• Corporate firewalls usually allow HTTP traffic
• Slow data transfer
• git clone <url>
• Creates a local repository for a remote repo given by <url>
• git remote add <remote-name> <url>
• Add a git remote specified by <remote-name> for the repo at <url>
• git pull <remote-name> <branch>
• Pull changes from the branch <branch> of remote repo mapped to <remote-name>
• git push <remote-name> <branch>
• Push changes to the branch <branch> of remote repo mapped to <remote-name>
