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Building a System Information Fetch Tool in Bash

#bash #linux #scripting #system

I once needed a quick system overview—CPU load, memory usage, disk space—but opening multiple commands felt inefficient. Instead of running top, df -h, and free -m separately, I decided to automate everything in a single Bash script.

The result? A custom system fetch tool that provides essential system details at a glance. In this guide, you'll learn how to build your own step by step, improving your Bash scripting skills along the way.

Step 1: The Basics (What We’re Fetching)

Before we jump into coding, let’s outline what information we need:

✅ CPU Model & Load (/proc/cpuinfo, top)

✅ Memory Usage (free -m)

✅ Disk Space (df -h)

✅ System Uptime (uptime)

✅ Network Information (ip a, hostname -I)

Step 2: Writing the Script (Fundamentals First)

1️⃣ Shebang & Setup

Start by specifying Bash as the interpreter and clearing the screen:

#!/bin/bash
clear
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2️⃣ Fetching CPU Info

Extract the CPU model name using grep on /proc/cpuinfo:

cpu_model=$(grep "model name" /proc/cpuinfo | head -1 | cut -d ':' -f2)
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Get the CPU load using top (or uptime for a lightweight alternative):

cpu_load=$(top -bn1 | grep "load average" | awk '{print $10}')
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3️⃣ Checking Memory Usage

Use free -m to display RAM usage in MB:

mem_usage=$(free -m | awk 'NR==2{printf "Used: %sMB / Total: %sMB", $3, $2}')
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4️⃣ Fetching Disk Space

List available disk space using df -h:

disk_usage=$(df -h | awk '$NF=="/"{printf "Used: %d%%", $5}')
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5️⃣ Displaying Network Info

Fetch the current IP address:

ip_address=$(hostname -I | awk '{print $1}')
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Step 3: Formatting Output for Readability

Instead of printing raw text, format the output neatly using colors and spacing:

echo -e "\033[32mSystem Information:\033[0m"
echo "-------------------------------"
echo -e "CPU Model: $cpu_model"
echo -e "CPU Load: $cpu_load"
echo -e "Memory: $mem_usage"
echo -e "Disk Space: $disk_usage"
echo -e "IP Address: $ip_address"
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🔹 Why it’s useful:

  • Colors improve readability
  • Consistent spacing makes it visually appealing

Step 4: Running the Script

  1. Save the script as sysfetch.sh
  2. Make it executable: 
   chmod +x sysfetch.sh
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  1. Run it: 
   ./sysfetch.sh
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📌 Expected Output (Example):

System Information:
-------------------------------
CPU Model: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
CPU Load: 0.78
Memory: Used: 3800MB / Total: 16000MB
Disk Space: Used: 42%
IP Address: 192.168.1.10
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Step 5: Enhancing the Script

✅ Add Live Updates

Instead of a one-time report, refresh every few seconds:

while true; do
    clear
    ./sysfetch.sh
    sleep 5
done
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✅ Save Output to a Log File

Redirect output for future analysis:

./sysfetch.sh | tee system_report.txt
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✅ Make It Interactive

Allow users to choose what info to display:

echo "Select an option: [1] CPU [2] Memory [3] Disk [4] All"
read choice

case $choice in
    1) echo "CPU Model: $cpu_model" ;;
    2) echo "Memory: $mem_usage" ;;
    3) echo "Disk Space: $disk_usage" ;;
    4) ./sysfetch.sh ;;
    *) echo "Invalid option" ;;
esac
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Final Thoughts

Creating a custom system fetch tool is a great way to:

✅ Improve your Bash scripting skills

✅ Understand Linux system commands

✅ Make system monitoring more efficient

If you're a beginner, this project gives you real-world Bash experience. If you're advanced, you can customize it further with more data points.

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Discussion: What System Info Do You Track in Your Bash Scripts?

Drop a comment below and share what extra system details you’d add to this script!

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