class: center, middle # CSCI-UA 480.10: OSSD <br> ## Git Introductory Activity .author[ Instructor: Joanna Klukowska <br> ] .license[ Copyrigth: Joanna Klukowska, 2022 <br> Unless noted otherwise all content is released under a [Creative Commons Attribution-ShareAlike 4.0 International License](https://creativecommons.org/licenses/by/4.0/). ] --- ## Assumptions / Prerequisites - You have Git installed on your local system. - You have Git configured on your local system. - You have a GitHub account. --- - Find the `git_intro_activity` repository in the course organization on GitHub https://github.com/ossd-s24 -- - __Fork this repository to your local account__: 1. Click __Fork__ in the upper-right corner of the page when you are viewing the content of the repository. 2. If you are a member of one or more organizations, select your personal account to receive the fork. 3. You should be viewing your personal fork of the `git_intro_activity` now - verify the URL to make sure that this is the case. --- - __Clone your fork__: -- 1. In the browser, click the green button labeled __Code__. 2. If "SSH" is not selected, click __SSH__. 3. Click the clipboard icon to copy the URL in the box to your clipboard. 4. To clone the repository, in the terminal window, enter the Git command below, where URL is in your clipboard from step 3. ``` git clone URL ``` -- 5. This new repository will be given the same name as the repository on GitHub. Change directory into the root of this cloned repository: ``` cd git_intro_activity ``` Congratulations, you have cloned your fork to your local machine! --- - Look around, run - `git log` - `git remote -v` - `git status` what type of information does each of the commands give you? --- - __Add another remote__ You want to keep a _connection_ to the original repository that you forked, so that you have access to the changes made in that repository. This is accomplished by adding another remote to your local repository. -- To add a remote, you need the URL of the remote repository. The following steps are one way to get that URL. 1. In the browser, navigate to the original repository in the organization (not your own fork). 2. Click the green __Code__ button. 3. If "SSH" is not selected, click __SSH__, and copy it to your clipboard. 5. In the terminal add a named URL (called a remote) to your clone that points to this repository, which we'll call `upstream` (the name can be anything you wish). ``` git remote add upstream URL ``` 6. Run ``` git remote -v ``` how is the output from it different than when you executed this command on the previous slide? Congratulations, your local clone now knows where to find the upstream repository (i.e., the original project repository). --- - Work on the content of your local repository 1. create a new file called `my_jokes.txt` and add a single joke of your own to it 2. now, perform the following tasks: - add this file to the staging area - commit the changes - push the changes up to your fork (do you remember the instructions that accomplish those three steps? ) -- ``` git add my_jokes.txt ``` ``` git commit -m "Created my own collection of jokes" ``` ``` git push origin main ``` Congratulations! You just added your content to your fork. --- - Work on the content a bit more ... 1. the file `fun.txt` has three jokes in it, rate each of them on a scale from 1 (not so funny) to 3 (very funny), save the changes to the file and then 2. add the changed file to the staging area and run ``` git status ``` what type of information does this give you? -- 3. commit your changes, but do not push them to your fork --- - __Synchronizing with upstream__ 1. As you are busy working on your own copy of the repository, other people are making changes to the original upstream repository. You want to get these changes incorporated into the files that you are working on. To do so, run ``` git pull upstream master ``` Git will prompt you for a commit message. Since files are being modified, this event is recorded in the commit log. Either enter a new message, or accept the message that Git suggests. <br> (If Git opened a `vi` window for you to edit the commit message, you can exit it by pressing `:wq` ) Read the messages that git prints to the terminal after you finish editing the commit message. What do they tell you? -- 2. Look at the content of `fun.txt` file. What happened? 3. Look at the list of files in your local repository. Is the file `my_jokes.txt` still there? -- Git was able to merge the changes that were made in upstream and your changes without any issues. --- - __Synchronizing with upstream again ...__ 1. You'll repeat the steps from the previous slide, but this time you will need to help Git in merging the changes. 2. Run ``` git pull upstream master ``` Read the messages that Git prints. This time the messages are different than in the previous pull. What do they tell you? Congratulations!!! You just got a merge conflict. --- - __Synchronizing with upstream again ...__ 3 . Look at the file `fun.txt`, you will see lines that look something like this: ``` <<<<<<< HEAD Rating: 1 ======= Rating: 3 >>>>>>> 305029d109b13d32eb188afb53a1a978164445f9 ``` Git shows you the changes that conflict. In the part above `=======` it shows you the content of your local repository. In the part below, it shows you the content from the upstream. It is now up to you, the human, to decide which of these changes you wish to keep. -- 4 . To resolve the conflict, edit the file and pick which of the two lines you wish to keep. Remove the lines starting with `>>>>>>>>>` and `<<<<<<<<<<`. 5 . When you are done with editing the file, you will need to add it to the staging area and commit it: ``` git add fun.txt git commit -m "merging changes manually" ``` This concludes the merge from the upstream. --- - __Update your fork__ 1. Push all the changes to your own fork. 2. Use `git log` to see the commit history. 3. How would you go back to one of the earlier commit points? --- class:middle, center # The End