ntop

A real-time system resource monitor for Linux, inspired by htop but focused on network and disk I/O monitoring.

Features

• System Overview: Real-time CPU (cores/threads/load) and memory usage in header
• Network Monitoring: Track RX/TX rates per network interface with scrollable list
• NFS I/O Statistics: Monitor NAS/network filesystem I/O operations
• Disk I/O Statistics: Monitor read/write rates per physical device
• Disk Usage Display: View filesystem usage (like df -h) with adaptive column widths
• Process Monitoring: CPU%, MEM%, disk I/O, connections per process with horizontal scrolling
• User Statistics: Aggregate resource usage by user (press t)
• Process Details: View detailed process info including command line, status, threads (press Enter)
• Interactive Filtering: Filter processes by username or PID
• Multi-sorting: Sort processes by CPU, MEM, READ, WRITE, CONN, or PID
• Responsive UI: Smooth scrolling with keyboard navigation

Installation

From Source

git clone https://github.com/WangLabCSU/ntop.git
cd ntop
cargo build --release
sudo cp target/release/ntop /usr/local/bin/

Prerequisites

• Rust 1.70 or higher
• Linux kernel 2.6.33+ (for /proc/diskstats support)

Usage

ntop

Keyboard Shortcuts

Panel Navigation

The UI is divided into panels that can be focused using Tab:

1. Network - Network interface statistics
2. NFS I/O - NFS mount I/O statistics (if present)
3. Disk I/O - Physical disk I/O statistics
4. Disk Usage - Filesystem usage information
5. Processes - Process list with resource usage

When a panel is focused, its border is highlighted and you can scroll its contents.

Sort Order

Press s to cycle through:

1. CPU% (default)
2. MEM%
3. READ (read bytes/sec)
4. WRITE (write bytes/sec)
5. CONN (connections)
6. PID

User Statistics

Press t to view resource usage aggregated by user:

• Process count per user
• Total CPU% per user
• Total MEM% per user
• Total read/write rates
• Total connections

Process Details

Select a process in the Processes panel and press Enter to view:

• Full command line
• Process status (Running, Sleeping, etc.)
• Parent PID
• UID/GID
• Thread count
• Virtual and physical memory
• Executable path
• Working directory

Data Sources

ntop reads from the following Linux /proc files:

• /proc/loadavg - System load average
• /proc/meminfo - Memory statistics
• /proc/cpuinfo - CPU information
• /proc/net/dev - Network interface statistics
• /proc/net/rpc/nfs - NFS client statistics
• /proc/diskstats - Disk I/O statistics
• /proc/mounts - Filesystem mount information
• /proc/[pid]/stat - Process CPU, memory, and state info
• /proc/[pid]/status - Process detailed status
• /proc/[pid]/io - Process I/O statistics
• /proc/[pid]/cmdline - Process command line
• /proc/[pid]/fd/ - Process file descriptors (for connection counting)

Architecture

ntop/
├── src/
│   ├── main.rs       # Application entry point and event loop
│   ├── system.rs     # System information (CPU, memory, load)
│   ├── network.rs    # Network statistics collection
│   ├── disk.rs       # Disk I/O and usage collection
│   ├── nfs.rs        # NFS I/O statistics collection
│   ├── process.rs    # Process statistics collection
│   └── ui.rs         # Terminal UI rendering
├── Cargo.toml
└── README.md

Platform Support

• Linux: Full support
• macOS: Not supported (requires /proc filesystem)
• Windows: Not supported

Development

Running Tests

cargo test

Running with Debug Output

RUST_LOG=debug cargo run

Building Release

cargo build --release

Contributing

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Inspired by htop and btop
• Built with ratatui for terminal UI