dsopt

Find and reclaim disk space from build artifacts — node_modules and Rust target/ directories.

dsopt walks a filesystem once with a parallel native scanner, shows you what those directories actually cost, and removes the ones you pick. Built as a single Rust binary on ratatui + crossterm — no Python, no virtualenv, no runtime dependencies.

Website: https://handyutils.github.io/dsopt · Crate: https://crates.io/crates/dsopt

Install

cargo install dsopt

Prebuilt archives for macOS (Apple Silicon and Intel), Linux x64/ARM64, and Windows x64 are attached to every release.

Update

dsopt --update      # check crates.io and reinstall when a newer release exists
dsopt --update --force   # reinstall even when already current

Use

dsopt                      # open the TUI and scan the whole filesystem
dsopt ~/code ~/work        # scan only the places that grow
dsopt --threads 8          # 1-8 scanner threads (default 4)
dsopt --list               # print a table instead of opening the TUI
dsopt --list --json        # one JSON object per line, for scripts

Flags

Flag	Meaning
`ROOTS...`	Roots to scan. Defaults to `/`.
`--threads <N>`	Scanner threads, 1–8. Default 4.
`--list`	Print candidates instead of opening the TUI.
`--json`	With `--list`, emit one JSON object per line.
`--update`	Install the newest published release.
`--force`	With `--update`, reinstall even when already current.

Keyboard shortcuts

Key	Action
`Space`	select / unselect the highlighted directory
`A` / `N`	select all / select none
`D`	remove the selected directories
`R`	rescan the filesystem
`T`	scanner thread settings
`↑` `↓` `PgUp` `PgDn` `Home` `End`	move through candidates
`?`	help overlay
`Q`	quit

What it detects

Detector	Directory name	Typed as
JavaScript dependencies	`node_modules`	`node_modules`
Rust build output	`target`	`rust_target`

Nested detectors collapse into their outermost parent, so a single removal reclaims the whole subtree rather than double-counting a node_modules buried inside another project's dependencies. Candidates are deduplicated by (device, inode), which stops macOS volume aliases from being counted twice.

Safety

Removal is permanent — there is no Trash and no undo, and the TUI says so before doing anything. A directory is deleted only when all of the following hold:

it resolved successfully and is a real directory;
it sits strictly inside the scan root, and is not the root itself;
it is not /, /System, /Users, or /Applications;
it is not under a virtual filesystem or macOS volume alias — /dev, /proc, /sys, /System/Volumes/Data, /System/Volumes/VM, /System/Volumes/Preboot, /System/Volumes/Update, /private/var/vm, /private/var/db/dyld.

The same checks run again immediately before each delete, not only when the scan is collected.

How it works

Scan — parallel-disk-usage builds a size tree over the root with a rayon thread pool; a second pass collects and sorts candidates. Live counters are shared through atomics and streamed to the status line while the walk runs.
Cache — the last completed scan is written to ~/.cache/dsopt/last_scan.json (honouring XDG_CACHE_HOME), so reopening dsopt is instant. Press R for a fresh walk.
Remove — deletions run on a background thread and report progress per directory, so the UI never blocks.

Development

cargo build            # debug binary at target/debug/dsopt
cargo test             # unit + integration tests
cargo fmt --check
cargo clippy --all-targets --all-features -- -D warnings

The library (src/lib.rs, src/app.rs, src/update.rs) holds all logic; dsopt.rs is the thin CLI entry point. CI runs format, tests, clippy, and cargo package on every push.

dsopt 0.1.1