sysmon - Zero-Dependency System Monitoring Tool

A minimal, zero-dependency system resource monitoring and analysis tool for developers and system administrators.

Why sysmon?

When you need to check system performance without installing bloated monitoring tools or complex dependencies, sysmon gives you clean, real-time insights with zero external dependencies. Built for situations where you need quick answers, not complex setup.

Features

• Resource Tracking: CPU, Memory, Disk Usage, Network I/O
• Process Analysis: Top processes by resource usage
• Historical Data: Track trends over time with configurable intervals
• Multiple Output Formats: Terminal tables, JSON, CSV for easy parsing
• Threshold Alerts: Get notified when resources exceed limits
• Cross-Platform: Works on Linux, macOS, and Windows (Node.js >= 18.0.0)
• Zero Dependencies: No npm packages required

Quick Start

npx sysmon --interval 5 --count 10  # Monitor for 10 intervals of 5 seconds
sysmon --top 5                      # Show top 5 processes by CPU usage
sysmon --json                      # Output in JSON format

Installation

npm install -g sysmon

Usage

Basic Monitoring

# Monitor system every 2 seconds, 3 times
sysmon --interval 2 --count 3

# Continuous monitoring (Ctrl+C to stop)
sysmon

# Save monitoring results to a file
sysmon --count 5 --output-file system-stats.json

Process Analysis

# Top 10 CPU-consuming processes
sysmon --top 10 --cpu

# Top 5 memory-consuming processes
sysmon --top 5 --mem

# Show processes using most disk I/O
sysmon --top 8 --disk

Output Formats

# JSON output for scripting
sysmon --json --count 5

# CSV format for spreadsheet analysis
sysmon --csv --interval 10 --count 3

# Pretty terminal tables (default)
sysmon

Threshold Alerts

# Alert when CPU exceeds 80%
sysmon --cpu-threshold 80 --count 5

# Alert when memory exceeds 90%
sysmon --mem-threshold 90 --interval 30

# Combine thresholds and save to file
sysmon --cpu-threshold 80 --mem-threshold 85 --count 10 --output-file alerts.json

API Usage

const { SysMonitor } = require('./index');

const monitor = new SysMonitor();

// Get current snapshot
const snapshot = await monitor.snapshot();
console.log(`CPU: ${snapshot.cpu.usage.toFixed(1)}%`);

// Start monitoring with callback
monitor.start({
  interval: 2000,
  count: 10
}, (snapshot, index) => {
  console.log(`Snapshot ${index}: ${snapshot.cpu.usage}% CPU`);
});

Examples

Development Server Monitoring

# Monitor while running dev server
node server.js & sysmon --interval 3 --top 5

Production Analysis

# Check server performance over 5 minutes
sysmon --interval 60 --count 5 --json > server-stats.json

Quick Health Check

# Simple one-liner health check
sysmon --count 1 | grep -E "(CPU|Memory|Disk)"

Output Format

Terminal Table (Default)

System Resource Monitor - 2024-06-03 11:56:00
┌─────────────────────────────────────────────────────┐
│              Resource Usage                          │
├─────────────────┬───────────┬───────────┬───────────┤
│     CPU         │ 23.4%     │ 1 core    │ 2.4°C     │
│     Memory      │ 62.1%     │ 8.3/12GB  │ 823MB/s   │
│     Disk        │ 45.8%     │ 256/500GB │ 1.2MB/s   │
│     Network     │ 125KB/s  │ ↓/↑       │           │
├─────────────────┼───────────┼───────────┼───────────┤
│    Processes (Top 3)                                  │
│     node       │ 45.2%     │ 1.2GB     │ 512MB/s   │
│     chrome     │ 12.8%     │ 3.4GB     │ 128MB/s   │
│     vscode     │ 8.3%      │ 1.8GB     │ 64MB/s    │
└─────────────────┴───────────┴───────────┴───────────┘

JSON Output

{
  "timestamp": "2024-06-03T11:56:00.000Z",
  "cpu": {
    "usage": 23.4,
    "cores": 4,
    "temperature": 2.4
  },
  "memory": {
    "usage": 62.1,
    "total": 12884901888,
    "used": 8000000000,
    "available": 4884901888,
    "swap": {
      "total": 8589934592,
      "used": 0
    }
  },
  "disk": {
    "usage": 45.8,
    "total": 500000000000,
    "used": 229000000000,
    "free": 271000000000,
    "readSpeed": 1200000,
    "writeSpeed": 800000
  },
  "network": {
    "downloadSpeed": 125000,
    "uploadSpeed": 45000
  },
  "processes": [
    {
      "pid": 1234,
      "name": "node",
      "cpu": 45.2,
      "memory": 1200000000,
      "diskRead": 512000000,
      "diskWrite": 256000000
    }
  ]
}

Development

git clone https://github.com/sulthonzh/sysmon
cd sysmon
npm install
npm test

License

MIT - see LICENSE file

Contributing

1. Fork the repository
2. Create a feature branch
3. Add tests for new functionality
4. Run tests: npm test
5. Submit a pull request

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Built with ❤️ for developers who value simplicity and performance.