Check Internet Connection Using Bash Script (Simple & Effective Guide)

Check Internet Connectivity

In many scenarios—like automation, cron jobs, or IoT devices—you need to verify internet connectivity before continuing a task. Using a Bash script is one of the fastest and most reliable ways to do this.

This post covers:

  • How to write a Bash script to detect internet connection
  • Different methods: ping, curl, wget
  • Real-world use cases and tips

✅ Method 1: Check Internet Using ping

This method is simple and works in most environments.

#!/bin/bash

ping -c 1 google.com > /dev/null 2>&1

if [ $? -eq 0 ]; then
    echo "Internet is available."
else
    echo "Internet is NOT available."
fi

Explanation:

  • ping -c 1 google.com sends one packet to Google
  • > /dev/null 2>&1 hides the output
  • $? checks the exit status (0 = success)

✅ Method 2: Using curl

#!/bin/bash

curl -s --head http://www.google.com | grep "200 OK" > /dev/null

if [ $? -eq 0 ]; then
    echo "Internet is available."
else
    echo "Internet is NOT available."
fi

Note: This checks if HTTP headers respond with a success code.

✅ Method 3: Silent Check with wget

#!/bin/bash

wget -q --spider http://google.com

if [ $? -eq 0 ]; then
    echo "Internet is available."
else
    echo "Internet is NOT available."
fi

🔄 Use Cases

  • 💻 Startup Scripts – Wait for internet before syncing backups
  • 📦 IoT Devices – Check connectivity before sending data
  • 🔄 Cron Jobs – Only run tasks if internet is available
  • 🧪 System Monitoring – Detect connection loss with alerts

🧠 Bonus: Loop Until Internet Is Available

#!/bin/bash

until ping -c1 google.com &>/dev/null; do
  echo "Waiting for internet..."
  sleep 5
done

echo "Internet is available. Proceeding..."

⚠️ Tips and Best Practices

TipBenefit
Use -c 1 in ping to reduce delayFaster response time
Avoid hardcoding domainsUse DNS or IPs suited to your region
Redirect output to /dev/nullKeeps your logs clean
Use fallback domainsIn case primary domain is unreachable

Checking internet availability via a Bash script is a lightweight and efficient method suitable for servers, Linux-based devices, and automated tasks. You now know three ways to do it—use whichever best fits your environment!

Have a unique use case for checking internet with Bash?
Drop your example or enhancement in the comments below and share this post with your fellow Linux users! 📡🐧


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