If you are a new developer, you probably use a nice GUI (Graphical User Interface) to code. It's easy. But when you start doing real work—like backend systems, deployment, or CI/CD—you will need to use the Terminal.

Using the terminal and Bash commands is a skill you must have.

This article is for new developers who are not used to the command line.

Commands You Should Know

Basics & File Management

• pwd, ls, cd, touch, mkdir, rm, cat, less, head, tail, echo

Searching & Editing

• grep, find, nano

Managing Git

• git clone, git status, git log

Processing Text

• awk, sed, jq

Calling APIs & Basic Networking

• curl, ping, wget, netstat, lsof

1 Basics and File Management

pwd – Where am I?

This command shows you the path of the folder you are in right now.

bash
pwd

It will display something like this: /Users/yourname/projects/myapp

ls – What's in here?

This lists all the files and folders in your current directory.

bash
ls          # A short list of files and folders.
ls -lah     # A detailed list of all files.

• -l gives you more details (like size and date).
• -a shows all files, even hidden ones (those starting with a dot .).
• -h makes file sizes easy to read (like KB or MB).

cd – Change folder

Use this to move between folders.

bash
cd bash_cmd_learn      # Go into the 'bash_cmd_learn' folder.
cd ..       # Go back up to the parent folder.
cd -        # Go back to the last folder you were in.

touch – Create an empty file

This creates a new, empty file.

bash
touch rean.txt   # Creates a new file named rean.txt.

If the file already exists, this command just updates its timestamp.

mkdir – Make a new folder

bash
mkdir logs          # Creates a new folder named 'logs'.
mkdir -p data/db    # Creates 'data' folder and then 'db' folder inside it.

The -p option is useful. It creates the parent folder if it's not there.

rm – Remove a file or folder

bash
rm rean.txt      # Deletes the file rean.txt.
rm -rf logs/        # Deletes the 'logs' folder and everything inside it.

• -r means recursive, so it deletes the whole folder.
• -f means force, so it doesn't ask you for confirmation.

Be very careful with rm -rf. It deletes everything forever and does not ask you. There is no undo.

cat – Read a whole file

This command prints the entire content of a file to the screen. Good for small files.

bash
cat README.md

less – Read a file page by page

If a file is very long, use less. It lets you scroll up and down.

bash
less 2000_log_file.log

Press q to exit.

head and tail – See the start or end of a file

Sometimes you only need to see the first few lines or the last few lines.

bash
head app.js        # Shows the first 10 lines.
tail app.js        # Shows the last 10 lines.

echo – Print text

This command prints text or the value of a variable.

bash
echo "Hello, Developer"
echo $HOME          # Shows the path to your home directory.

You can also use it to write text to a file.

bash
echo "PORT=8080" > .env     # Creates a file named .env with this text.
echo "DEBUG=true" >> .env    # Adds a new line to the end of .env.

• > overwrites the file.
• >> adds to the end of the file.

2. Searching & Editing

grep – Find text inside files

This is one of the most useful commands. It searches for a pattern of text.

bash
# Search for any usage of async functions in JS files.
grep "async function" *.js

# Search for all lines that import modules (ES6 style).
grep "^import" *.js

find – Find files or folders

Use this to find files by name, type, or size.

bash
# Find all JavaScript files in the src/ directory and its subdirectories.
find ./src -name "*.js"

# Find all test files that end with .test.js.
find . -type f -name "*.test.js"

nano – The simple editor

nano is a very easy-to-use editor for beginners allow you edit the files in the terminal.

bash
nano index.js

This opens config.yaml for you to edit.

• Press Ctrl + O to save your changes.
• Press Ctrl + X to exit.

3. Basic Git Commands

You will use Git every day. Here are the most common commands.

• git status - See what files have changed.
• git add <file> - Prepare a file to be saved.
• git commit -m "Your message" - Save your changes with a message.
• git log --oneline - See a short history of all your saves.
• git pull - Get the latest changes from the server.
• git push - Send your saved changes to the server.
• git clone <url> - Copy a project from a server to your computer.

4. Processing Text

awk – Get a specific column of text

Imagine you have a log file where data is separated by spaces. awk can pull out just the columns you want.

bash
# From a Node.js server log, print the first column (the timestamp).
awk '{print $1}' server.log

# Print the IP address if it's the third column.
awk '{print $3}' server.log

sed – Find and replace text

sed is for finding and replacing text in a stream or file.

bash
# Replace 'development' with 'production' in a .env file.
# This only prints the result; it doesn't change the file.
sed 's/development/production/g' .env

# To update the file in-place, use the -i flag.
sed -i 's/development/production/g' .env

jq – Work with JSON

If you work with APIs or config files like package.json, jq is a powerful tool for handling JSON.

bash
# Pretty-print package.json
cat package.json | jq '.'

# Get the value of the "name" field in package.json
cat package.json | jq '.name'

# Get all dependency names from package.json
cat package.json | jq '.dependencies | keys[]'

5. Network Commands You Should Know

ping – Is the server online?

Use ping to check if you can reach a server.

bash
ping google.com

# Ping 4 times and then stop.
ping -c 4 google.com

If it works, you’ll see replies with response times (e.g., 64 bytes from ... time=23.4 ms). If it’s not , you’ll get errors like Request timed out or Destination Host Unreachable.

curl – Talk to APIs

curl is a great tool for testing APIs from the command line.

bash
# Send a GET request to a health check endpoint.
curl http://localhost:8080/health

# Send a POST request with JSON data.
curl -X POST http://localhost:8080/users \
  -H "Content-Type: application/json" \
  -d '{"name": "new dev"}'

wget – Download files

Use wget to download a file from a URL.

bash
wget https://example.com/some-file.zip

lsof and netstat – What's using that port?

If you get an error like "port already in use," these commands can help.

bash
# Show me what program is using port 8080.
lsof -i :8080

This will show you the command and PID using the port. You can then use kill to stop it if you need to.

You don't need to remember all these commands at once. The best way to learn is to start using them for your real projects.

Start with simple things: moving between folders, editing a config file, checking logs, or running your app.

Once you are comfortable, you will see that the command line is a powerful tool. You can build your own scripts for testing, deploying, and monitoring your work. And that is a very important skill for a developer.