disk-manager

A WinDirStat-style disk usage analyzer: a squarified treemap plus a size-sorted folder tree, with a headless JSON mode for scripts and agents.

Two frontends share one scanner and one size tree: a native window, and a terminal UI for SSH sessions and servers. Both can delete or trash what they show. Built for macOS (Finder integration, app bundle), but everything works on any Unix.

Build & run

cargo run                    # GUI, no scan yet
cargo run -- ~/Downloads     # GUI, starts scanning immediately
cargo run -- --tui ~/        # terminal UI
cargo test

Without a DISPLAY or WAYLAND_DISPLAY (an SSH session, say) the terminal UI is picked automatically when it is compiled in. --tui forces it.

Frontends are cargo features, gui (default) and tui. On a server, skip the windowing stack entirely:

cargo install --path . --no-default-features --features tui
disk-manager /var/lib        # no path scans the current directory

Terminal UI

Same two panels as the window: folder tree on the left, treemap on the right, breadcrumb above it. The treemap is painted with half-block glyphs, so each cell carries two tiles vertically, and uses 24-bit colour when COLORTERM says the terminal has it (falls back to the 256-colour cube otherwise, e.g. inside an unconfigured tmux).

key	effect
Tab	switch between tree and treemap
↑ ↓ / j k	move
← → / h l	tree: collapse / expand · treemap: previous / next tile
Space	fold / unfold a folder
Enter	zoom the treemap into the folder
Backspace / u	zoom out one level
g / G	first / last
d	delete permanently (asks first)
t	move to trash (asks first)
r	rescan
?	key help · q quits

The mouse works too when the terminal forwards it: click selects, double-click opens, the wheel scrolls the tree, the breadcrumb is clickable.

Deleting is blocked while the scan runs, in both frontends: the walker would keep streaming entries from under the folder and recreate it in the tree. Note that t on a server puts things in ~/.local/share/Trash, which nobody ever empties there; d is usually what you want remotely.

On macOS, build a real .app bundle so the OS shows the standard Documents/Desktop/Downloads permission prompts:

./macos/bundle.sh
open "target/Disk Manager.app" --args "$HOME"

Headless mode

scan runs the same parallel scanner and prints a JSON size tree to stdout. The shaping flags exist to bound the output so it fits in a fixed context:

disk-manager scan ~ --depth 3 --top 10 --min-size 10485760 --pretty

flag	effect
--depth N	emit at most N levels below the root (0 = unlimited)
--top N	keep the N largest children per level (0 = all)
--min-size BYTES	drop entries below this size
--pretty	multi-line JSON instead of one line
--cross-filesystems	descend into other mounts (off by default, like du -x)

How sizes are counted

Sizes are allocated bytes on disk — 512-byte blocks, exactly what du reports, not the logical file length. Three consequences worth knowing:

• A small file still costs a full block; sparse files cost less than their size.
• Hard links are counted once, deduplicated by (dev, ino).
• Other filesystems are skipped by default. On macOS this matters even for a single volume: scanning / would otherwise follow the firmlink at /System/Volumes/Data and count your data twice.

scan_total_matches_du in src/scan.rs pins this down against real du -sx output, hard link included.

Layout

file	role
src/scan.rs	parallel jwalk walker, streams batches over a channel
src/tree.rs	incremental aggregated size tree
src/treemap.rs	squarified treemap geometry, no UI dependency
src/state.rs	frontend-neutral app state: owns the scan, drains it, applies actions, runs confirmed deletes
src/ui/	what both frontends share: the actions views emit, the flattened tree rows, node colours
src/gui/	eframe frontend (feature gui)
src/tui/	ratatui frontend (feature tui)
src/cli.rs	argument parsing and the headless JSON mode
src/actions.rs	reveal / trash / delete

Path components are kept as OsString all the way through, because a component path is what a delete action rebuilds an absolute path from — it has to round-trip byte-for-byte even when a filename is not valid UTF-8. Names are converted lossily only at display time, via Node::display_name.