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This page is the third part of an introduction to Git:

  1. Installation
  2. Quickstart
  3. Cheat Sheet
  4. Gitignore

Open the terminal and cd into the folder where your Git repository (repo) is located (or where you want it to be located if you are about to create one). From here, the following commands can be used to version control your project:

Create a New Repository

Terminal Command Action
git init Create a new, blank, Git repository in the current folder. Initially it won’t have any branches: you first need to commit something (anything!) in order for a master branch to be created.
git clone <repository> <directory> Download a replica (clone) of an existing Git repository from a remote (cloud) location such as GitHub or Bitbucket into a sub-folder within the current folder.
• <repository> is the URL of the repo, eg https://github.com/<username>/<repo_name> or https://bitbucket.org/<username>/<repo_name>
• <directory> is the name of the sub-folder that will be created on your computer to house the cloned repo
• This repo will be created with branches because when you download a repo you download all the pieces of it, including its branches (unless, of course, the repo you downloaded doesn’t have any branches)
git remote add origin <url> Add a remote location to sync your repo to (eg on GitHub or Bitbucket) and give it the nickname “origin”
• This must be an existing empty repo on GitHub or Bitbucket
• When you created this empty repo on GitHub or Bitbucket you should not have selected the option to include a “gitignore”. If you included a “gitignore” the remote repo will not be empty!
• <url> is the URL of the remote, eg https://bitbucket.org/<username>/<repo_name>/src/master/
git remote -v View a project’s remotes, ie where in the cloud your repo can sync to
git remote remove <name> Remove a remote location. Usually <name> will be “origin”.

Delete a repository simply by deleting the entire folder on your computer. Note that this will only delete the local copy of that repo; any copies in the cloud or on other computers will remain.

Adding and Committing Files/Changes

As you add or remove files and edit them on your local machine you will be able to track and ‘save’ (commit) or undo (‘reset’) your changes as follows:

Terminal Command Action
git status Inspect the contents of the working directory and the staging area (view the changes you have made since the last commit and see which ones you have earmarked to keep)
git restore <filename> Undo the changes you’ve made to a file
git add <filename> Add a file from the working directory to the staging area (‘stage one file’), earmarking the changes you have made to it as edits you want to keep
git add -A Add all files from the working directory to the staging area (‘stage all files’)
git reset Remove all files from the staging area (‘undo staging’). The implication is that you don’t want to keep the changes you have made to these files but you don’t want to undo the changes either.
git commit -m "<message>" Store the files in the staging area in the repository (‘commit the files’/‘commit the changes’). Your changes are now ‘saved’.
git push origin <branch_name> Copy the changes that have been made and committed on your local branch into the corresponding branch on the remote location (‘push the changes’). By default, the remote is called “origin”.
git merge <branch_name> Take all the changes that have been made and committed in a different branch and include them in the current branch as well (‘merge in changes’)
git merge master Take all the changes that have been merged into your master branch and include them in the current branch as well (‘merge in changes’)
git merge origin/<branch_name> Take all the changes that have been pushed into one of the remote’s branches and include them in your local branch as well
git merge origin/master Take all the changes that have been merged into the remote’s master branch and include them in your local branch as well

Change/Work With a Repository

Terminal Command Action
git branch <new_branch> Create a new branch. If you try to create a new branch on a brand new repo (ie one where you haven’t made any commits yet) it will not work because there is no master branch. You will get an error saying fatal: Not a valid object name: 'master'
git branch Show the branches and which one you are on
git branch --list Identical to the above
git checkout <branch_name> Switch to a different branch
git branch -d <branch_name> Delete branch

Change/Work With Files in a Repository

Terminal Command Action
git diff <filename> See the changes that have been made to a file
git diff See the changes that have been made to all the files in the repository
git log Show a list of all the previous commits
git show HEAD Show the HEAD commit (ie see the changes that were made in the previous commit)
git checkout HEAD <filename> Restore a file in your working directory to make it look exactly as it did when you last made a commit
git reset HEAD <filename> Reset a file in the staging area to be the same as what it was in the HEAD commit
git reset <SHA> Reset all files to their versions from a previous commit using the SHA hash of that commit

Stashing Changes

Remove the changes you’ve made, but keep them stored away in case you want to use them again:

Terminal Command Action
git stash Save your WIP (work in progress) and clean your current working directory (remove all the changes you’ve made since your last commit)
git stash push -m "message" Stash the WIP with a name
git stash list See which stashes you’ve stored
git stash pop Apply the most recent stash (take the changes and apply them to the relevant files) and delete it from the list of stashes
git stash pop stash@{2} Apply a specific stash and delete it from the list of stashes
git stash apply Apply the most recent stash and keep it in the list of stashes
git stash apply stash@{2} Apply a specific stash and keep it in the list of stashes

Updating a Repository

Terminal Command Action
git fetch Check to see if changes have been pushed to the origin’s version of the current branch. Download them if so, but don’t incorporate them into your local branch.
git pull Merge in the changes that have been pushed to the origin’s version of the current branch
git fetch && git merge FETCH_HEAD Equivalent to git pull*
git diff master origin/master See the differences between the files in the local version of the master branch and those in the origin’s version of the master branch. This is useful to see if a pull will cause a conflict.
git diff master origin/master --summary A summarised version of the above
git pull master Merge changes from the (local) master branch into your current branch
git pull origin master Merge changes from the remote copy of the master branch into your current branch
git mergetool Open GUI tool to resolve conflicts

*A pull is the same as a fetch plus a merge

Oh No! I’ve Accidentally Made Some Changes on the Wrong Branch!

Simply move your changes to the correct branch:

git stash
git checkout <correct_branch>
git pull
git stash pop

Oh No! I’ve Accidentally Committed Some Changes to the Wrong Branch!

Merge these change into the right branch then remove the changes from the wrong branch:

# Checkout the branch on which you should have made the changes
git checkout <correct_branch>
git pull
# Merge the branch on which you made the changes into this branch
git merge <wrong_branch>
git commit
git push
# Go back to the wrong branch
git checkout <wrong_branch>
# Either do this to reset it back to what is on the origin:
git reset --hard origin/<wrong_branch>
# Or do this to remove the last commit
git reset --hard HEAD^

Finally, consider adding a Gitignore file to your repo.

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