Developer Cheat Sheets

Essential quick reference guides for web developers

🔌 Common Development Ports Reference

Port	Primary Use	Frameworks/Services	Protocol
3000	Frontend Development	React, Express, Rails, Gatsby	HTTP
8080	Backend/App Server	Spring Boot, Tomcat, Vue	HTTP
5173	Modern Build Tool	Vite.js	HTTP
4200	Frontend Framework	Angular, Ionic	HTTP
5000	Backend Framework	Flask, .NET Core	HTTP
8000	Backend Framework	Django, PHP built-in server	HTTP
9000	Development Tools	SonarQube, PHP-FPM	HTTP
3306	Database	MySQL, MariaDB	TCP
5432	Database	PostgreSQL	TCP
27017	Database	MongoDB	TCP
6379	Cache/Data Store	Redis	TCP
1433	Database	Microsoft SQL Server	TCP

📚 Git Commands Cheat Sheet

Basic Commands

Command	Description	Example
git init	Initialize new repository	git init my-project
git clone	Clone existing repository	git clone https://github.com/user/repo.git
git status	Check repository status	git status
git add	Stage changes for commit	git add .
git commit	Commit staged changes	git commit -m "Add feature"
git push	Push commits to remote	git push origin main
git pull	Pull changes from remote	git pull origin main

Branching & Merging

Command	Description	Example
git branch	List, create, or delete branches	git branch feature-x
git checkout	Switch branches	git checkout feature-x
git switch	Switch branches (newer syntax)	git switch feature-x
git merge	Merge branch into current	git merge feature-x
git branch -d	Delete branch	git branch -d feature-x

Undoing Changes

Command	Description	Example
git reset	Unstage changes	git reset HEAD file.txt
git restore	Restore working tree files	git restore file.txt
git revert	Create new commit that undoes changes	git revert HEAD
git stash	Temporarily save changes	git stash save "WIP"
git stash pop	Apply stashed changes	git stash pop

🌐 HTTP Status Codes Reference

2xx Success

Code	Status	Meaning	Common Use
200	OK	Request succeeded	Standard response for successful HTTP requests
201	Created	New resource created	POST request successfully created a resource
204	No Content	Success but no content to return	DELETE request succeeded

3xx Redirect

Code	Status	Meaning	Common Use
301	Moved Permanently	Resource permanently moved	Permanent URL redirection
302	Found	Resource temporarily moved	Temporary URL redirection
304	Not Modified	Resource not modified since last request	Cache validation

4xx Client Error

Code	Status	Meaning	Common Use
400	Bad Request	Invalid request syntax	Client sent malformed request
401	Unauthorized	Authentication required	User not authenticated
403	Forbidden	Server refuses to authorize	User lacks required permissions
404	Not Found	Resource not found	Requested URL doesn't exist
429	Too Many Requests	Rate limit exceeded	Client sent too many requests

5xx Server Error

Code	Status	Meaning	Common Use
500	Internal Server Error	Generic server error	Unexpected server condition
502	Bad Gateway	Invalid response from upstream	Proxy received invalid response
503	Service Unavailable	Server temporarily unavailable	Server overloaded or maintenance
504	Gateway Timeout	Upstream server timeout	Proxy didn't receive timely response

📦 NPM vs Yarn Command Comparison

Action	NPM	Yarn
Install dependencies	npm install	yarn install or yarn
Add package	npm install package	yarn add package
Add dev dependency	npm install package --save-dev	yarn add package --dev
Remove package	npm uninstall package	yarn remove package
Update package	npm update package	yarn upgrade package
Global install	npm install -g package	yarn global add package
Run script	npm run script	yarn run script or yarn script
List packages	npm list	yarn list
Check outdated	npm outdated	yarn outdated
Init new project	npm init	yarn init

⌨️ Essential Terminal Commands

File Operations (Unix/Mac/Linux)

Command	Description	Example
ls	List directory contents	ls -la
cd	Change directory	cd /path/to/dir
mkdir	Create directory	mkdir my-folder
rm	Remove files/directories	rm -rf folder
cp	Copy files	cp file.txt backup.txt
mv	Move/rename files	mv old.txt new.txt
cat	Display file contents	cat file.txt
grep	Search text patterns	grep "error" log.txt

File Operations (Windows CMD)

Command	Description	Example
dir	List directory contents	dir /a
cd	Change directory	cd C:\path\to\dir
mkdir	Create directory	mkdir my-folder
del	Delete files	del file.txt
copy	Copy files	copy file.txt backup.txt
move	Move/rename files	move old.txt new.txt
type	Display file contents	type file.txt
findstr	Search text patterns	findstr "error" log.txt

Process Management (Unix/Mac/Linux)

Command	Description	Example
ps	Show running processes	ps aux
top	Display system processes	top
kill	Terminate process	kill -9 1234
lsof	List open files/ports	lsof -i :3000

Network Diagnostics

Command	Description	Example
ping	Test network connectivity	ping google.com
curl	Transfer data from URLs	curl https://api.example.com
netstat	Network statistics	netstat -ano
traceroute	Trace packet route	traceroute google.com

🐳 Docker Development Cheat Sheet

Container Management

Command	Description	Example
docker run	Run a container	docker run -p 3000:3000 myapp
docker ps	List running containers	docker ps -a
docker stop	Stop container	docker stop container-id
docker rm	Remove container	docker rm container-id
docker logs	View container logs	docker logs -f container-id
docker exec	Execute command in container	docker exec -it container-id bash

Image Management

Command	Description	Example
docker build	Build image from Dockerfile	docker build -t myapp .
docker images	List images	docker images
docker rmi	Remove image	docker rmi image-id
docker pull	Pull image from registry	docker pull nginx:latest
docker push	Push image to registry	docker push myapp:latest

Docker Compose

Command	Description	Example
docker-compose up	Start services	docker-compose up -d
docker-compose down	Stop and remove services	docker-compose down
docker-compose logs	View service logs	docker-compose logs -f
docker-compose ps	List services	docker-compose ps
docker-compose restart	Restart services	docker-compose restart