atlas.doomwalker

A lightning-fast disk space analyzer with a treemap. Reads the NTFS Master File Table directly on Windows for near-instant scans of millions of files; falls back to a portable filesystem walker on Linux and macOS. Ships both a polished TUI and a browser-based UI.

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Why

Walking a filesystem with the OS file APIs is slow because every directory descent is a syscall. WizTree's trick on NTFS is to bypass the OS entirely and read the Master File Table — a single contiguous structure that lists every file and directory on the volume — straight off the disk. A 4 TB drive with a million files scans in seconds rather than minutes.

atlas.doomwalker does the same on Windows. On platforms without an MFT (Linux, macOS, FAT/exFAT volumes, network shares) it falls back to a cross-platform walker so the rest of the tool — the treemap, the navigation, the web UI — still works.

Install

Pre-built binaries

Grab the binary for your platform from the releases page and put it on your PATH. Six binaries are published per release: windows-amd64, windows-arm64, linux-amd64, linux-arm64, darwin-amd64, darwin-arm64.

From source

git clone https://github.com/fezcode/atlas.doomwalker
cd atlas.doomwalker
go build -o atlas.doomwalker .

Or with gobake to produce all six platform binaries at once:

gobake build

Usage

atlas.doomwalker [flags] [drive|path]

TUI

.\atlas.doomwalker.exe                # scan C: with the MFT scanner (Windows)
.\atlas.doomwalker.exe D:             # scan D:
.\atlas.doomwalker.exe --walker C:    # skip MFT, use the portable walker

./atlas.doomwalker /home              # walk /home (Linux/macOS)
./atlas.doomwalker --walker ~/Downloads

Browser UI

atlas.doomwalker --serve              # binds 127.0.0.1:7878 by default
atlas.doomwalker --serve --addr :8080 # bind a different address

The server prints a URL; open it. The page is a single-page app that lazily fetches subtrees, so even a 50 GB folder with hundreds of thousands of entries stays responsive.

Flags

Flag	Meaning
--serve	Run the browser UI instead of the TUI
--addr <host:port>	Bind address for --serve (default 127.0.0.1:7878)
--walker	Force the cross-platform walker (skip MFT)
-v, --version	Print version
-h, --help	Print help

Keyboard

TUI

Key	Action
↑ / k	Move selection up
↓ / j	Move selection down
Home / g	First item
End / G	Last item
PgUp / PgDn	Jump 10
Enter / → / l	Drill into selected directory
Backspace / ← / h	Go up
s	Cycle sort: size → name → item count
.	Toggle hidden / $-prefixed entries
o	Open selection in Explorer
d	Delete selection (with confirmation)
q / Ctrl+C	Quit

Browser UI

Key	Action
Click tile	Drill into directory
Click crumb	Jump to that level
Esc / ⌫	Up one level
1–9	Open the Nth largest item

Permissions

The MFT scanner reads the raw NTFS volume, which on Windows requires Administrator privileges. If you launch without elevation, the program re-launches itself elevated through UAC. Pass --walker if you want to skip the elevation prompt and use the portable scanner instead.

The walker needs no special privileges and silently skips paths it can't read.

How it works

                              ┌────────────────────┐
                              │   main.go          │
                              │   (flag parsing,   │
                              │    UAC, dispatch)  │
                              └─────────┬──────────┘
                                        │
                          ┌─────────────┴─────────────┐
                          │                           │
                  Windows + admin               anything else
                          │                           │
                ┌─────────▼─────────┐       ┌─────────▼─────────┐
                │  internal/mft     │       │ internal/walker   │
                │  raw \\.\C:       │       │ filepath.WalkDir  │
                │  parses MFT       │       │ statx fallback    │
                │  records          │       │                   │
                └─────────┬─────────┘       └─────────┬─────────┘
                          │                           │
                          └─────────────┬─────────────┘
                                        │
                              *mft.FileNode tree
                                        │
                          ┌─────────────┴─────────────┐
                          │                           │
                ┌─────────▼─────────┐       ┌─────────▼─────────┐
                │  internal/ui      │       │  internal/web     │
                │  Bubble Tea TUI   │       │  http.Server +    │
                │  squarified       │       │  embedded SPA     │
                │  treemap          │       │  (SVG treemap)    │
                └───────────────────┘       └───────────────────┘

The squarified treemap algorithm (Bruls, Huijsen & van Wijk, 2000) is implemented in both Go (for the TUI) and JavaScript (for the browser UI), so layouts are visually consistent across the two front-ends.

Project layout

atlas.doomwalker/
├── main.go                # entry, dispatch
├── main_windows.go        # UAC elevation
├── main_other.go          # POSIX stubs
├── Recipe.go              # gobake build tasks
├── internal/
│   ├── mft/               # NTFS MFT scanner (Windows)
│   ├── walker/            # cross-platform filepath.WalkDir scanner
│   ├── treemap/           # squarified algorithm (Go)
│   ├── ui/                # Bubble Tea TUI
│   └── web/               # HTTP server + embedded SPA
│       └── static/        # index.html, app.css, app.js
└── build/                 # output from `gobake build`

Acknowledgements

• charmbracelet/bubbletea and lipgloss for the TUI.
• t9t/gomft for the Go MFT record parser.
• WizTree for proving how fast a disk analyzer can be.
• The squarified treemap paper by Mark Bruls, Kees Huijsen and Jarke J. van Wijk.

License

MIT — see LICENSE.