Git is a distributed version control system that helps developers collaborate on projects of any scale. Linus Torvalds, the developer of the Linux kernel, created Git in 2005 to help control the Linux kernel's development.

How to initialize a Git repo:

Everything starts from here. The first step is to initialize a new Git repo locally in your project root. You can do so with the command below:

git init

How to check your Git configuration:

The command below returns a list of information about your git configuration including user name and email:

git config -l

How to setup your Git username:

With the command below you can configure your user name:

git config --global user.name "Global Open Versity"

How to setup your Git user email:

This command lets you setup the user email address you'll use in your commits.

git config --global user.email "info@globalopenversity.com"

How to cache your login credentials in Git:

You can store login credentials in the cache so you don't have to type them in each time. Just use this command:

git config --global credential.helper cache

How to add a file to the staging area in Git:

The command below will add a file to the staging area. Just replace filename_here with the name of the file you want to add to the staging area.

git add filename_here

How to add all files in the staging area in Git

If you want to add all files in your project to the staging area, you can use a wildcard . and every file will be added for you.

git add .

How to check a repository's status in Git:

This command will show the status of the current repository including staged, unstaged, and untracked files.

git status

How to commit changes in the editor in Git:

This command will open a text editor in the terminal where you can write a full commit message.

A commit message is made up of a short summary of changes, an empty line, and a full description of the changes after it.

git commit

How to commit changes with a message in Git:

You can add a commit message without opening the editor. This command lets you only specify a short summary for your commit message.

git commit -m "your commit message here"

How to commit changes (and skip the staging area) in Git:

You can add and commit tracked files with a single command by using the -a and -m options.

git commit -a -m "your commit message here"

How to see your commit history in Git:

This command shows the commit history for the current repository:

git log

How to see your commit history including changes in Git:

This command shows the commit's history including all files and their changes:

git log -p

How to see a specific commit in Git:

This command shows a specific commit.

Replace 'commit-id' with the id of the commit that you find in the commit log after the word commit.

git show commit-id

How to see log stats in Git:

This command will cause the Git log to show some statistics about the changes in each commit, including line(s) changed and file names.

git log --stat

How to see changes made before committing them using "diff" in Git:

You can pass a file as a parameter to only see changes on a specific file.
git diff shows only unstaged changes by default.

We can call diff with the --staged flag to see any staged changes.

git diff

git diff all_checks.py

git diff --staged

How to see changes using "git add -p":

This command opens a prompt and asks if you want to stage changes or not, and includes other options.

git add -p

How to remove tracked files from the current working tree in Git:

This command expects a commit message to explain why the file was deleted.

git rm filename

How to rename files in Git:

This command stages the changes, then it expects a commit message.

git mv oldfile newfile

How to ignore files in Git:

Create a .gitignore file and commit it.

How to revert unstaged changes in Git:

git checkout filename

How to revert staged changes in Git:

You can use the -p option flag to specify the changes you want to reset.

git reset HEAD filename

git reset HEAD -p

How to amend the most recent commit in Git:

git commit --amend allows you to modify and add changes to the most recent commit.

!!Note!!: fixing up a local commit with amend is great and you can push it to a shared repository after you've fixed it. But you should avoid amending commits that have already been made public.

How to rollback the last commit in Git:

git revert

Git revert will create a new commit that is the opposite of everything in the given commit.
We can revert the latest commit by using the head alias like this:

git revert HEAD

How to rollback an old commit in Git:

You can revert an old commit using its commit id. This opens the editor so you can add a commit message.

git revert commit_id

How to create a new branch in Git:

By default, you have one branch, the main branch. With this command, you can create a new branch. Git won't switch to it automatically – you will need to do it manually with the next command.

git branch branch_name

How to switch to a newly created branch in Git:

When you want to use a different or a newly created branch you can use this command:

git checkout branch_name

How to list branches in Git:

You can view all created branches using the git branch command. It will show a list of all branches and mark the current branch with an asterisk and highlight it in green.

git branch

How to create a branch in Git and switch to it immediately:

In a single command, you can create and switch to a new branch right away.

git checkout -b branch_name

How to delete a branch in Git:

When you are done working with a branch and have merged it, you can delete it using the command below:

git branch -d branch_name

How to merge two branches in Git:

To merge the history of the branch you are currently in with the branch_name, you will need to use the command below:

git merge branch_name

How to show the commit log as a graph in Git:

We can use --graph to get the commit log to show as a graph. Also, --oneline will limit commit messages to a single line.

git log --graph --oneline

How to show the commit log as a graph of all branches in Git:

Does the same as the command above, but for all branches.

git log --graph --oneline --all

How to abort a conflicting merge in Git:

If you want to throw a merge away and start over, you can run the following command:

git merge --abort

How to add a remote repository in Git

This command adds a remote repository to your local repository (just replace https://repo_here with your remote repo URL).

git add remote https://repo_here

How to see remote URLs in Git:

You can see all remote repositories for your local repository with this command:

git remote -v

How to get more info about a remote repo in Git:

Just replace origin with the name of the remote obtained by
running the git remote -v command.

git remote show origin

How to push changes to a remote repo in Git:

When all your work is ready to be saved on a remote repository, you can push all changes using the command below:

git push

How to check remote branches that Git is tracking:

This command shows the name of all remote branches that Git is tracking for the current repository:

git branch -r

How to fetch remote repo changes in Git:

This command will download the changes from a remote repo but will not perform a merge on your local branch (as git pull does that instead).

git fetch

How to check the current commits log of a remote repo in Git

Commit after commit, Git builds up a log. You can find out the remote repository log by using this command:

git log origin/main

How to merge a remote repo with your local repo in Git:

If the remote repository has changes you want to merge with your local, then this command will do that for you:

git merge origin/main

How to get the contents of remote branches in Git without automatically merging:

This lets you update the remote without merging any content into the
local branches. You can call git merge or git checkout to do the merge.

git remote update

How to push a new branch to a remote repo in Git:

If you want to push a branch to a remote repository you can use the command below. Just remember to add -u to create the branch upstream:

git push -u origin branch_name

How to remove a remote branch in Git:

If you no longer need a remote branch you can remove it using the command below:

git push --delete origin branch_name_here

How to use Git rebase:

You can transfer completed work from one branch to another using git rebase.

git rebase branch_name_here

Git Rebase can get really messy if you don't do it properly. Before using this command I suggest that you re-read the official documentation here

How to run rebase interactively in Git:

You can run git rebase interactively using the -i flag.
It will open the editor and present a set of commands you can use.

git rebase -i master

# p, pick = use commit
# r, reword = use commit, but edit the commit message
# e, edit = use commit, but stop for amending
# s, squash = use commit, but meld into previous commit
# f, fixup = like "squash", but discard this commit's log message
# x, exec = run command (the rest of the line) using shell
# d, drop = remove commit

How to force a push request in Git:

This command will force a push request. This is usually fine for pull request branches because nobody else should have cloned them.
But this isn't something that you want to do with public repos.

git push -f

Help. Get help with git commands

git help <git command>

Git basic workflow

git add . //stage all files with changes after working
or
git add <SPECIFIC_FILE/DIRECTORY>$ git commit //opens interactive shell for type commit message
or
git commit -m "YOUR COMMIT MESSAGE"$ git pull //pull from remote branch tracked by current local branch
or
git pull origin <BRANCH> //BRANCH - master, dev, feature-x...$ git push //if already tracking a remote branch

Stashing

Put our work to a stack until we pull new changes from remote.

git stash //stash unstaged changes
git stash save "add style to our site" //stash with a message//pull from remote and merge
git stash show //show stash
git stash show -p //show the diff of stash
git stash list$ git stash pop
or
git stash pop stash@{0} //stash@{0} - stash number$ git stash apply

Create a branch from the stash

git stash branch <BRANCH_NAME> stash@{1} //stash@{1} - stash no.

Clean stash

git stash drop stash@{1}
git stash clear //clear all stashes

Tagging

Useful for tracking releases/versions.

git tag //list tags
git checkout <TAG> //checkout the code at tag(version)
git tag -a v0.0.3 -m "version 0.0.3" //create a new tag v0.0.3
git push --tags

.gitignore - remove cached files

When the files are already identified by git .gitignore cannot remove them. This happens mostly when you are adding a new entry to .gitignore for files which are already identified by git.

git rm -r --cached . && git add . && git commit -m "fixing .gitignore" // You can run above commands one by one with more control/clarity
git rm -r --cached .
git add .
git commit -m "fixing .gitignore"