Git Beginner

git log <file>

Only display commits that include the specified file. This is an easy way to see the history of a particular file.

git config --global --edit

Open the global configuration file in a text editor for manual editing.

git clean -n

Perform a "dry run" of git clean. This will show you which files are going to be removed without actually doing it.

git push <remote> --all

Push all of your local branches to the specified remote.

git push <remote> <branch>

Push the specified branch to <remote>, along with all of the necessary commits and internal objects. This creates a local branch in the destination repository. To prevent you from overwriting commits, Git won't let you push when it results in a non-fast-forward merge in the destination repository.

git rebase -i <base>

Rebase the current branch onto <base>, but use an interactive rebasing session. This opens an editor where you can enter commands (described below) for each commit to be rebased. These commands determine how individual commits will be transferred to the new base. You can also reorder the commit listing to change the order of the commits themselves.

git rebase <base>

Rebase the current branch onto <base>, which can be any kind of commit reference (an ID, a branch name, a tag, or a relative reference to HEAD).

git remote rm <name>

Remove the connection to the remote repository called <name>.

git reset <file>

Remove the specified file from the staging area, but leave the working directory unchanged. This unstages a file without overwriting any changes.

git clean -df

Remove untracked files and untracked directories from the current directory.

git clean -xf

Remove untracked files from the current directory as well as any files that Git usually ignores.

git clean -f

Remove untracked files from the current directory. The -f (force) flag is required unless the clean.requireForce configuration option is set to false (it's true by default). This will not remove untracked folders or files specified by .gitignore.

git clean -f <path>

Remove untracked files, but limit the operation to the specified path.

git clean

Removes untracked files from your working directory. This is really more of a convenience command, since it's trivial to see which files are untracked with git status and remove them manually. Like an ordinary rm command, git clean is not undoable, so make sure you really want to delete the untracked files before you run it. The git clean command is often executed in conjunction with git reset --hard. Remember that resetting only affects tracked files, so a separate command is required for cleaning up untracked ones. Combined, these two commands let you return the working directory to the exact state of a particular commit.

git remote rename <old-name> <new-name>

Rename a remote connection from <old-name> to <new-name>.

git branch -m <branch>

Rename the current branch to <branch>.

git reset --hard

Reset the staging area and the working directory to match the most recent commit. In addition to unstaging changes, the --hard flag tells Git to overwrite all changes in the working directory, too. Put another way: this obliterates all uncommitted changes, so make sure you really want to throw away your local developments before using it.

git reset

Reset the staging area to match the most recent commit, but leave the working directory unchanged. This unstages all files without overwriting any changes, giving you the opportunity to re-build the staged snapshot from scratch. If git revert is a "safe" way to undo changes, you can think of git reset as the dangerous method. When you undo with git reset(and the commits are no longer referenced by any ref or the reflog), there is no way to retrieve the original copy—it is a permanent undo. Care must be taken when using this tool, as it's one of the only Git commands that has the potential to lose your work. Like git checkout, git reset is a versatile command with many configurations. It can be used to remove committed snapshots, although it's more often used to undo changes in the staging area and the working directory. In either case, it should only be used to undo local changes—you should never reset snapshots that have been shared with other developers.

git checkout master

Return to the master branch. Branches are covered in depth in the next module, but for now, you can just think of this as a way to get back to the "current" state of the project.

git add -p

Begin an interactive staging session that lets you choose portions of a file to add to the next commit. This will present you with a chunk of changes and prompt you for a command. Use y to stage the chunk, n to ignore the chunk, s to split it into smaller chunks, e to manually edit the chunk, and q to exit.

git log --graph --decorate --oneline

A few useful options to consider. The --graph flag that will draw a text based graph of the commits on the left hand side of the commit messages. --decorate adds the names of branches or tags of the commits that are shown. --oneline shows the commit information on a single line making it easier to browse through commits at-a-glance.

At it's core what is a commit

A logical way to bundle various changes together.

git add

Adds a change in the working directory to the staging area. It tells Git that you want to include updates to a particular file in the next commit. However, git add doesn't really affect the repository in any significant way—changes are not actually recorded until you run git commit.

git log --stat

Along with the ordinary git log information, include which files were altered and the relative number of lines that were added or deleted from each of them.

git checkout <commit> <file>

Check out a previous version of a file. This turns the <file> that resides in the working directory into an exact copy of the one from <commit> and adds it to the staging area.

git checkout <existing-branch>

Check out the specified branch, which should have already been created with git branch. This makes <existing-branch> the current branch, and updates the working directory to match.

git checkout HEAD <file>

Checkout most recent version of <file>

git commit --amend

Combine the staged changes with the previous commit and replace the previous commit with the resulting snapshot. Running this when there is nothing staged lets you edit the previous commit's message without altering its snapshot. A convenient way to fix up the most recent commit. It lets you combine staged changes with the previous commit instead of committing it as an entirely new snapshot. It can also be used to simply edit the previous commit message without changing its snapshot.

git checkout -b <new-branch>

Create and check out <new-branch>. The -b option is a convenience flag that tells Git to run git branch <new-branch> before running git checkout <new-branch>.

git commit

Commits the staged snapshot to the project history. Committed snapshots can be thought of as "safe" versions of a project—Git will never change them unless you explicity ask it to. While they share the same name, this command is nothing like svn commit. Snapshots are committed to the local repository, and this requires absolutely no interaction with other Git repositories.

git log --oneline

Condense each commit to a single line. This is useful for getting a high-level overview of the project history.

git config

Configures the Git installation (or an individual repository) from the command line. This command can define everything from user info to preferences to the behaviour of a repository.

git clone

Copies an existing Git repository. This is sort of like svn checkout, except the "working copy" is a full-fledged Git repository—it has its own history, manages its own files, and is a completely isolated environment from the original repository. As a convenience, cloning automatically creates a remote connection called origin pointing back to the original repository. This makes it very easy to interact with a central repository.

git branch <branch>

Create a new branch called <branch>. This does not check out the new branch.

git remote add <name> <url>

Create a new connection to a remote repository. After adding a remote, you'll be able to use <name> as a convenient shortcut for <url> in other Git commands.

git config --global alias.<alias-name> <git-command>

Create a shortcut for a Git command.

git init <directory>

Create an empty Git repository in the specified directory. Running this command will create a new folder called <directory> containing nothing but the .git subdirectory.

git config --global user.email <email>

Define the author email to be used for all commits by the current user.

git config --global user.name <name>

Define the author name to be used for all commits by the current user.

git config user.name <name>

Define the author name to be used for all commits in the current repository. Typically, you'll want to use the --global flag to set configuration options for the current user.

git config --system core.editor <editor>

Define the text editor used by commands like git commit for all users on the current machine. The <editor> argument should be the command that launches the desired editor (e.g., vi).

git branch -d <branch>

Delete the specified branch. This is a "safe" operation in that Git prevents you from deleting the branch if it has unmerged changes.

git log -p

Display the patch representing each commit. This shows the full diff of each commit, which is the most detailed view you can have of your project history.

git log

Displays commit history. It lets you list the project history, filter it, and search for specific changes. While git status lets you inspect the working directory and the staging area, git log only operates on the committed history.Log output can be customized in several ways, from simply filtering commits to displaying them in a completely user-defined format.

git status

Displays which changes have been staged, which haven't, and which files aren't being tracked by Git.

git fetch <remote>

Fetch all of the branches from the repository. This also downloads all of the required commits and files from the other repository.

git pull <remote>

Fetch the specified remote's copy of the current branch and immediately merge it into the local copy. This is the same as git fetch <remote> followed by git merge origin/<current-branch>.

git branch -D <branch> (CAPS)

Force delete the specified branch, even if it has unmerged changes. This is the command to use if you want to permanently throw away all of the commits associated with a particular line of development.

git revert <commit>

Generate a new commit that undoes all of the changes introduced in <commit>, then apply it to the current branch.

git reflog

Git keeps track of updates to the tip of branches using a mechanism called reflog. This allows you to go back to changesets even though they are not referenced by any branch or tag. After rewriting history, the reflog contains information about the old state of branches and allows you to go back to that state if necessary.

git init --bare <directory>

Initialize an empty Git repository, but omit the working directory. Shared repositories should always be created with the --bare flag (see discussion below). Conventionally, repositories initialized with the --bare flag end in .git. For example, the bare version of a repository called my-project should be stored in a directory called my-project.git.

git init

Initializes a new Git repository by creating a .git subdirectory in the project root, which contains all metadata for the repo.

git pull --rebase <remote>

Instead of using git merge to integrate the remote branch with the local one, use git rebase.

git log -n <limit>

Limit the number of commits by <limit> . For example, git log -n 3 will display only 3 commits.

git branch

List all of the branches in your repository. Lets you create, list, rename, and delete branches. It doesn't let you switch between branches or put a forked history back together again. For this reason, git branch is tightly integrated with the git checkout and git merge commands.

git merge --no-ff <branch>

Merge the specified branch into the current branch, but always generate a merge commit (even if it was a fast-forward merge). This is useful for documenting all merges that occur in your repository.

git merge <branch>

Merge the specified branch into the current branch. Git will determine the merge algorithm automatically (discussed below).

git merge

Merging is Git's way of putting a forked history back together again. The git merge command lets you take the independent lines of development created by git branch and integrate them into a single branch. Note that all of the commands presented below merge into the current branch. The current branch will be updated to reflect the merge, but the target branch will be completely unaffected. Again, this means that git merge is often used in conjunction with git checkout for selecting the current branch and git branch -d for deleting the obsolete target branch.

git reset --hard <commit>

Move the current branch tip backward to <commit> and reset both the staging area and the working directory to match. This obliterates not only the uncommitted changes, but all commits after <commit>, as well.

git reset <commit>

Move the current branch tip backward to <commit>, reset the staging area to match, but leave the working directory alone. All changes made since <commit> will reside in the working directory, which lets you re-commit the project history using cleaner, more atomic snapshots.

git checkout (wrt branches)

Navigate between the branches created by git branch. Checking out a branch updates the files in the working directory to match the version stored in that branch, and it tells Git to record all new commits on that branch. Think of it as a way to select which line of development you're working on.

When should revert be used?

Reverting should be used when you want to remove an entire commit from your project history. This can be useful, for example, if you're tracking down a bug and find that it was introduced by a single commit. Instead of manually going in, fixing it, and committing a new snapshot, you can use git revert to automatically do all of this for you.

git checkout -b <new-branch> <existing-branch>

Same as 'git checkout -b <new-branch>' but base the new branch off of <existing-branch> instead of the current branch.

git fetch <remote> <branch>

Same as 'git pull <remote>' but only fetch the specified branch.

git push <remote> --force

Same as 'git push <remote> <branch>' but force the push even if it results in a non-fast-forward merge. Do not use the --force flag unless you're absolutely sure you know what you're doing.

git log --author="<pattern>"

Search for commits by a particular author. The <pattern> argument can be a plain string or a regular expression.

git log --grep="<pattern>"

Search for commits with a commit message that matches <pattern> , which can be a plain string or a regular expression.

git checkout

Serves three distinct functions: 1 - checking out files, 2 - checking out commits 3 - checking out branches. Checking out a commit makes the entire working directory match that commit. This can be used to view an old state of your project without altering your current state in any way. Checking out a file lets you see an old version of that particular file, leaving the rest of your working directory untouched.

git log <since>..<until>

Show only commits that occur between <since> and <until>. Both arguments can be either a commit ID, a branch name, HEAD, or any other kind of revision reference.

git reflog --relative-date

Show the reflog with relative date information (e.g. 2 weeks ago).

git push <remote> --tags

Tags are not automatically pushed when you push a branch or use the --all option. The --tags flag sends all of your local tags to the remote repository.

--bare

The --bare flag creates a repository that doesn't have a working directory, making it impossible to edit files and commit changes in that repository. Central repositories should always be created as bare repositories because pushing branches to a non-bare repository has the potential to overwrite changes. Think of --bare as a way to mark a repository as a storage facility, opposed to a development environment. This means that for virtually all Git workflows, the central repository is bare, and developers local repositories are non-bare.

git revert

Undoes a committed snapshot. But, instead of removing the commit from the project history, it figures out how to undo the changes introduced by the commit and appends a new commit with the resulting content. This prevents Git from losing history, which is important for the integrity of your revision history and for reliable collaboration.

git checkout <commit>

Update all files in the working directory to match the specified commit. You can use either a commit hash or a tag as the <commit> argument. This will put you in a detached HEAD state.