Git Tutorial PDF - Commands and Workflow

Git Status Not started Repository has several branches. One of the branch is designated as HEAD. This HEAD branch on remote determines which branch you will start on when you clone the repository Usual Flow in Git : There’s a Repository with a URL and it...

Git Status Not started Repository has several branches. One of the branch is designated as HEAD. This HEAD branch on remote determines which branch you will start on when you clone the repository Usual Flow in Git : There’s a Repository with a URL and it has many branches 1. User clones a “repository” using command : git clone A. Git creates a label/pointer called origin : This pointer points to the repository url you cloned remote origin Fetch URL: https://… Push URL: https://… B. Git downloads default branch : There can be several branches in a repository. Git marks one of the branches as default branch. It does so by creating a symbolic reference of HEAD for the branch designated as default. HEAD branch: main Git 1  NOTE: While cloning starts by downloading the default branch, you actually get all the branches from the remote repository. You can switch to other branches later using git checkout As you switch between branches using git checkout HEAD gets updated to point to the new branch. C. Git decides tracking-branch : Git has to decide an up-stream branch. This is the remote branch that your local branch needs to stay in synch with(pull and push). Git often sets up your local branch e.g. InProcess__My to track origin/InProcess_MY. Important commands : git remote show origin 2. Use makes changes to a file in the local branch of the repository. Before making any changes , A. git pull : In essence, git pull does two things: 1. : It fetches new commits and changes from a remote repository. This git fetch downloads the latest content from the remote, but it doesn't immediately integrate it into your local branch. 2. git merge : It merges the fetched changes into your current local branch. This combines the remote changes with your local work, creating a new "merge commit" that incorporates both sets of changes. Git 2  Git constantly detects changes watching your working directory. As soon as file is changed It notices difference from version stored in last commit. B. git status : We use the git status command to see the current state of repository. It updates the status relative to tracking branch Important Command to see tracking branch : git branch -vv C. git stage. : stages the changes to be committed. Staging allows you to select exactly which changes you want to include in particular commits. It can be helpful in partial commits. Its also helpful as a check mechanism. NOTE: You can un-stage changes by using ( git restore --staged ) D. git commit -m : This command creates a commit in your local repository. Git Comparing 2 branches Scenario Command Description Compare commits between Lists commits in branch B but not in git log A..B two branches branch A. git diff A B -- Shows differences for a specific file View specific file differences between two branches. Displays the file changes between See all changes in content git diff A..B branches. Git 3  Understanding Git Remote git remote The git remote command allows you to perform various actions related to remote repositories. By itself, git remote will list the names of the remotes that your repository is currently linked to. For example: $ git remote origin You’ll notice the word origin a lot. That’s because it’s the default name which refers to the remote repository. You can technically call it something different if you want. v Use the -v flag (for verbose) to display more details about the remotes associated with your local repo. For example: $ git remote -v origin https://github.com/omega9656/learn-code.git (fetch) origin https://github.com/omega9656/learn-code.git (push) add Use git remote add to add a remote to your local repository. $ git remote add For example, the following adds the Learn Code repo as the remote and names that remote origin. $ git remote add origin https://github.com/omega9656/learn-code.git remove Use git remote remove to remove a remote from your local repository. Git 4  $ git remote remove For example, if I had a remote called origin associated with my local repo, I could remove it like so: $ git remote remove origin Note: If you’re using an older version of Git, you may need to replace remove with rm. set-url If you only want to change the URL of the remote repository, you can use git remote set-url. (This is usually used if you typed the remote URL incorrectly or if the remote URL has changed.) $ git remote set-url For example, if I had a remote called origin and I wanted to change its URL to https://github.com/dusty-the-dog/learn-code.git, I would use: $ git remote set-url origin https://github.com/dusty-the-dog/learn-code.git Experiment I did with Git Concept Before Setting Upstream After Setting Upstream Your local branch InProcess__MY Your local branch InProcess__MY now pulls changes from Branch Setup pulled changes from InProcess origin/InProcess__MY (remote (remote branch). counterpart). InProcess__MY pushed to No change—InProcess__MY still Push Behavior origin/InProcess__MY. pushes to origin/InProcess__MY. git pull now fetches from git pull fetched from InProcess Pull Behavior origin/InProcess__MY (your remote (target branch of the pull request). branch). Now compares with Git Status Showed: Your branch is ahead of origin/InProcess__MY, so no longer Message 'origin/InProcess' by 1 commit. shows ahead of InProcess. Git 5  git status compared your branch Reason for git status now compares correctly with InProcess, which was Confusion with origin/InProcess__MY. unrelated to your push. This updated the upstream tracking Ran git branch --set-upstream- What You Did branch for InProcess__MY to to=origin/InProcess__MY. origin/InProcess__MY. Keeps your branch aligned with its Avoids confusion about branch Why It’s Useful remote counterpart comparisons. (origin/InProcess__MY). Key Concepts to Remember Concept Explanation Upstream Tracking The branch your local branch pulls changes from and Branch compares to in git status. git branch --set- Command to set or update the upstream tracking branch for a upstream-to local branch. Fetches changes from the upstream tracking branch and git pull Behavior merges them into your local branch. Push and pull branches can be different (e.g., pull from Push and Pull Branches InProcess, push to InProcess__MY). Why Track a Remote Tracking makes it easier to sync your local branch with its Branch? intended remote counterpart. Cloning a Repo with Checkout. There are two options for checking out initially git checkout --track git checkout -b InProcess_MY Feature/Behavior origin/InProcess_MY origin/InProcess_MY Git 6  Creates a new local branch Creates a new local branch and automatically sets it to InProcess_MY based on Purpose track the remote branch origin/InProcess_MY but does not origin/InProcess_MY. automatically track the remote branch. Automatically sets the local Does not track the remote branch unless Tracking Remote branch to track explicitly set later using git branch --set- Branch origin/InProcess_MY. upstream-to. Local branch directly tracks the remote branch. Push Push and pull require specifying the Default Behavior and pull operations work remote branch explicitly (e.g., git push After Creation seamlessly without extra origin InProcess_MY). configuration. Automatically names the Requires you to specify the local branch local branch the same as Branch Naming name explicitly (can be the same or the remote branch different from the remote branch name). (InProcess_MY). Simplifies No, you must configure tracking Yes, since tracking is Push/Pull manually or specify branch names automatically configured. Operations during push/pull. Ideal if you want a local Useful if you want to create a new Use Case branch that directly tracks branch (based on the remote branch) the remote branch. but with a different relationship or name. Command Shorter and more concise. More flexible, but slightly longer. Simplicity Example git push (pushes to git push origin InProcess_MY (remote Command After origin/InProcess_MY by branch must be specified explicitly). Setup default). Fails if a branch with the Error Handling (If Fails if a branch with the same name same name already exists Branch Exists) already exists locally. locally. Tracking Automatically configured: Not configured automatically; you need Configuration git branch -vv shows to run: git branch --set-upstream-to After Setup [origin/InProcess_MY]. origin/InProcess_MY. Understanding Git Fetch - all Git 7  When you run: sh CopyEdit git fetch --all Git contacts all configured remotes (e.g., origin ) and fetches the latest changes from all remote branches into their respective remote-tracking branches in your local repository. What Are Remote-Tracking Branches? Remote-tracking branches are local references to branches on a remote repository. They track the state of the remote branches but are read-only (you can’t directly commit to them). Their names are usually prefixed with origin/ (e.g., origin/main , origin/InProcess , etc.). Example Before Fetching Let's say your last fetch was a while ago. Your repository might have these branches: Local Branch Remote-Tracking Branch Status main origin/main Behind 5 commits develop origin/develop Up-to-date InProcess_MY origin/InProcess Behind 10 commits If someone pushes new changes to origin/main and origin/InProcess , you won't see them in your local repository until you fetch. What Happens After git fetch --all ? Git will update the remote-tracking branches ( origin/main , origin/InProcess , etc.) to reflect the latest commits on the remote repository. Git 8  It does not change your working directory or your local branches. You now have the latest snapshot of the remote branches but haven’t merged anything yet. You can check the status with: sh CopyEdit git branch -vv This will show which local branches are behind or ahead of their corresponding remote branches. Git 9