Projects / rtop

git clone https://molodetz.nl/retoor/rtop.git copy

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rtop

Author: retoor retoor@molodetz.nl

A terminal-based system monitoring tool written in C that displays comprehensive system statistics in a tabbed, auto-refreshing interface. rtop is designed as a lightweight alternative to htop with no external dependencies beyond the standard C library.

Features

• Tabbed interface with 5 dedicated views (CPU, Memory, Network, Disk, Process)
• Real-time system monitoring with configurable refresh interval
• Auto-rotate tabs at configurable interval
• Pause mode for copy/paste operations
• Per-core CPU utilization with temperature and frequency display
• Memory and swap usage statistics with task summary
• Process listing sorted by CPU or memory usage
• Network interface statistics with RX/TX rates and IP addresses
• Disk I/O statistics with IOPS
• Filesystem usage information
• Color-coded progress bars for utilization levels
• Terminal resize handling

Requirements

• Linux operating system
• GCC compiler (C99 compliant)
• Make build system

Building

make

The build produces a single binary rtop with minimal dependencies.

Build Options

make clean      # Remove build artifacts
make debug      # Build with debug symbols
make install    # Install to /usr/local/bin (requires root)

Usage

./rtop [OPTIONS]

Options:
  -d, --delay SECS   Update interval in seconds (default: 1.0)
  -r, --rotate SECS  Auto-rotate tabs every SECS seconds (0=off, default: 0)
  -s, --sort MODE    Sort by: cpu (default), mem
  -h, --help         Show help message
  -v, --version      Show version

Examples

./rtop              # Run with default settings
./rtop -d 2         # Update every 2 seconds
./rtop -r 5         # Auto-rotate tabs every 5 seconds
./rtop -s mem       # Sort processes by memory usage
./rtop -d 0.5 -r 3  # Fast refresh with 3-second tab rotation

Tabs

| Tab | Content | |-----|---------| | CPU | Per-core utilization bars, temperature, frequency, total usage | | Memory | RAM/Swap usage, buffers/cache, task summary (running, sleeping, stopped, zombie) | | Network | Interface list with IP addresses, RX/TX rates, total bytes transferred | | Disk | Per-device I/O rates, IOPS, filesystem mount points with usage | | Process | Detailed process list with PID, user, CPU%, MEM%, command |

Controls

| Key | Action | |-----|--------| | Left/Right arrows | Switch between tabs | | 1-5 | Jump directly to tab | | ESC | Pause refresh (for copy/paste) | | q / Q | Quit the application | | Ctrl+C | Terminate |

Technical Details

Data Sources

All system information is read from the Linux /proc and /sys filesystems:

| Source | Information | |--------|-------------| | /proc/stat | CPU statistics | | /proc/meminfo | Memory information | | /proc/[pid]/stat | Process information | | /proc/net/dev | Network statistics | | /proc/diskstats | Disk I/O statistics | | /sys/class/thermal/ | Temperature sensors | | /sys/devices/system/cpu/ | CPU frequency |

Performance

• Target CPU usage: <5%
• Startup time: <100ms
• Memory footprint: <10MB RSS

Project Structure

rtop/
├── include/
│   ├── cpu.h
│   ├── disk.h
│   ├── display.h
│   ├── filesystem.h
│   ├── memory.h
│   ├── network.h
│   ├── process.h
│   ├── system.h
│   └── terminal.h
├── src/
│   ├── cpu.c
│   ├── disk.c
│   ├── display.c
│   ├── filesystem.c
│   ├── main.c
│   ├── memory.c
│   ├── network.c
│   ├── process.c
│   ├── system.c
│   └── terminal.c
├── Makefile
└── README.md

License

This project is provided as-is for educational and personal use.

Files