safesweep

Clean caches and temp files that are provably safe to delete, and see what is eating your CPU.

Most cleaners guess which files are junk. safesweep does not guess: it only looks at locations it has a rule for (package-manager caches, ~/.cache, temp files, ...), and before it deletes anything it checks that nothing is using the files, that nothing in them changed recently, and that they are yours. If it cannot prove a file is safe to remove, it leaves it alone and tells you why. On WSL it also explains how to hand the freed disk space back to Windows.

Linux and WSL only (it reads /proc to see what programs are using).

The animation runs against a throwaway home directory with a faked clock; demo/make.sh rebuilds it.

Contents

Quick start · Install · Commands · How it decides what is safe · Rules · WSL · Exit codes · FAQ · Development · Documentation · License

Quick start

safesweep                  # 1. look: what could be removed, and why each item is or is not safe
safesweep clean            # 2. rehearse: what a cleanup would remove (deletes nothing)
safesweep clean --apply    # 3. do it

safesweep with no arguments is a read-only scan. Nothing is ever deleted without --apply (or the confirmation prompt in safesweep tui).

Install

Pick whichever fits your system:

cargo install safesweep                     # build from source (Rust 1.88 or newer)
cargo binstall safesweep                    # prebuilt binary, via cargo-binstall
brew install dpologdvinity/tap/safesweep    # Homebrew on Linux
pipx install safesweep                      # or: uv tool install safesweep
npm install -g safesweep                    # or: pnpm add -g / yarn global add / bun add -g
nix run github:dpologdvinity/safesweep      # Nix flake

Debian, Ubuntu and WSL (apt repository, gets updates with apt upgrade):

sudo install -d -m 0755 /etc/apt/keyrings
curl -fsSL https://dpologdvinity.github.io/safesweep/key.asc | sudo tee /etc/apt/keyrings/safesweep.asc >/dev/null
echo "deb [signed-by=/etc/apt/keyrings/safesweep.asc] https://dpologdvinity.github.io/safesweep stable main" | sudo tee /etc/apt/sources.list.d/safesweep.list
sudo apt update && sudo apt install safesweep

Single files. The releases page has .deb and .rpm packages and static binaries for x86_64 and aarch64, each with a .sha256 checksum:

sudo apt install ./safesweep_*_amd64.deb
sudo dnf install ./safesweep-*.x86_64.rpm

The .deb, .rpm and release tarballs include a man page and bash, zsh and fish completions. After cargo install, set up completions yourself, for example safesweep completions bash > ~/.local/share/bash-completion/completions/safesweep.

Commands

Command	What it does
safesweep or safesweep scan	Lists every candidate with its size, what it costs to get back, and ok or the reason it is skipped. Read-only.
safesweep scan --json	The same, as JSON, for scripts.
safesweep clean	Dry run: shows what would be removed and how much space it would free. Deletes nothing.
safesweep clean --apply	Removes what is ok, re-checking each item first, and logs every removal.
safesweep tui	Interactive list: pick the safe items and delete them after a confirmation.
safesweep why	Shows what is using the CPU right now.
safesweep completions SHELL	Prints a completion script (bash, zsh, fish, elvish, powershell).

Option for scan, clean and tui: --category ID (repeatable) limits the run to some rules, for example safesweep --category pip clean --apply. Options for why: --interval-ms N (how long to sample, at least 100, default 1000) and --top N (how many entries to list, default 10).

The removal log

Every removal is written to ~/.local/state/safesweep/<unix-time>.log, one line per path: the bytes freed, a tab, the path. The log is created before anything is deleted: if it cannot be created, nothing is removed. If it stops being writable partway through (a full disk, say), safesweep reports the removal it just made and stops.

tui: browse and delete interactively

safesweep tui shows the same candidates as scan, biggest first, with a size bar. Safe rows can be selected; skipped rows are greyed out with their reason and cannot be selected. Rows owned by other users are hidden (they can never be deleted).

Key	Action
j / k or arrow keys	move
space	select or unselect the row
a / n	select all safe rows / clear the selection
d or enter	delete the selection (asks you to press y)
q or esc	quit (also cancels a running scan)

Deleting uses exactly the same checks as clean --apply, and the list is rescanned afterwards.

why: what is eating the CPU

safesweep why samples /proc twice and prints how busy the machine is, CPU per program (summed across its processes, so twelve rustc jobs show as one line), and the busiest processes with their command lines. Percentages are per core, like top, so a busy process on a 12-core machine can reach 1200%. On WSL, only Linux processes are visible: if Task Manager shows vmmem busy but why is quiet, the load is on the Windows side.

How it decides what is safe

A candidate is skipped, with the reason shown, if any of these is true. The checks run when scanning and again right before each deletion.

• It is a symlink, or lies outside its rule's directory.
• It is the temp directory, or contains it.
• Anything inside belongs to another user (unless run as root).
• Anything inside changed recently, within the rule's age (the newer of modification time and inode change time, so a tree unpacked with tar or cp -p today counts as new).
• It holds a socket or a named pipe (a live tmux or X11 socket does not show up as an open file).
• Anything inside is open, memory-mapped, being executed, or the working directory of one of your processes, including processes in containers or other mount namespaces (matched by inode, not path). Other users' processes are only visible when run as root.
• It contains a .git directory (an editable install or git dependency can hold uncommitted work).
• Any part of it cannot be read, it contains a read-only directory (deleting would stop halfway), or it is or contains a mount point.
• /proc cannot be read, so open files cannot be checked.
• You are root and it is in the temp directory (containers and services with a private /tmp cannot be checked from outside).

HOME must be an absolute path (and, as root, owned by root: use sudo -H, not sudo -E). TMPDIR must be an absolute path that is not / and does not contain your home directory. Otherwise safesweep refuses to run.

Sizes count only files with a single hard link: uv hardlinks its cache into virtual environments, so deleting those files would free nothing, and safesweep does not pretend it would.

One honest limit: there is a tiny gap between the last check and the removal in which a program could open a file. The check runs just before the removal, and on Linux a program that already has a file open keeps working after it is deleted. The design and these trade-offs are explained in ARCHITECTURE.md.

Rules

A rule names a location and how to pick candidates in it. safesweep never considers a path no rule covers.

Category	Location	Minimum age	Cost to get back
xdg-cache	each entry in ~/.cache except pip and uv	7 days	network
pip	~/.cache/pip	1 day	network
uv	~/.cache/uv	1 day	network
npm	~/.npm/_cacache	1 day	network
cargo	~/.cargo/registry/cache	1 day	network
tmp	each entry in $TMPDIR (or /tmp)	7 days	free
pycache	every __pycache__ under ~ (opt-in: --category pycache)	none	free
artifacts	node_modules, target, .venv of idle git projects (opt-in: --category artifacts)	30 days	slow

xdg-cache treats any entry of ~/.cache untouched for 7 days as disposable, as the XDG standard describes the directory. If you keep something valuable there (a large downloaded model, say), either move it or check safesweep scan first: the table shows every candidate.

pycache and artifacts walk your home directory (skipping hidden directories), so they only run when you name them.

artifacts is deliberately strict. A build directory is listed only if a project file sits next to it (package.json for node_modules, Cargo.toml for target, pyproject.toml, requirements.txt or setup.py for .venv), a file only the tool creates sits inside it (pyvenv.cfg, CACHEDIR.TAG, .package-lock.json, ...), and the project's git history has been idle for 30 days (any commit, checkout or fetch, on any branch or linked worktree, counts as activity). Projects without a .git directory, and monorepo members without their own, are never listed. The whole project must also be unused by any of your processes, so a long-running server keeps its dependencies.

WSL

On WSL 2 the Linux filesystem lives in one virtual disk file, ext4.vhdx. Deleting files inside Linux frees space inside that file but does not make the file smaller, so Windows' free space does not change. After clean --apply frees space on WSL, safesweep prints the steps to compact the disk: export a backup, wsl --shutdown, then Optimize-VHD (or diskpart). It only prints them; it never runs them.

It deliberately does not suggest wsl --manage --set-sparse: WSL disabled sparse disks after data-corruption reports, and a sparse disk cannot be compacted with Optimize-VHD.

Exit codes

Code	Meaning
0	success
1	the command ran but something failed: a removal failed or could not be logged, /proc or the terminal was unusable
2	bad usage: unknown --category, unsafe HOME or TMPDIR, a flag that does not apply to the command

FAQ

Is it safe to run? scan and clean (without --apply) change nothing. clean --apply deletes only what passed every check listed above, and only caches and temp files the rules name, which programs recreate on demand.

Why was something skipped? The status column says why: modified within 7 days, in use by a process, owned by another user, and so on. Skipping is the tool being careful, not an error.

Can I undo a cleanup? No: deleted files are gone. That is why it only touches things that can be recreated. The log in ~/.local/state/safesweep/ lists exactly what was removed.

Why did the disk not get smaller on WSL? See WSL.

Does it work on macOS or Windows? No. It relies on /proc. On Windows, use it inside WSL.

safesweep --category pycache is slow. It walks your whole home directory. Seconds on a normal home, longer on very large ones.

Why not sudo -E? It keeps your HOME, which would let a user-controlled directory steer a root-level delete, so safesweep refuses it. Run it as yourself: it does not need root.

Development

You need Rust 1.88 or newer. Node 22 is only needed for the npm launcher tests.

cargo build                                   # build
cargo test                                    # all tests (a few use `unshare -rm`, see CONTRIBUTING.md)
cargo clippy --all-targets -- -D warnings     # lint; also fails on undocumented public items
cargo fmt                                     # format
cargo doc --no-deps --open                    # browse the API documentation
cargo llvm-cov --summary-only                 # line coverage (needs cargo-llvm-cov)
node --test npm/test.js                       # npm launcher tests

See CONTRIBUTING.md for the workflow, conventions and how to add a rule.

Documentation

• ARCHITECTURE.md: how it is built and why; the safety model.
• CONTRIBUTING.md: set up, test, and submit a change.
• SECURITY.md: how to report a vulnerability.
• RELEASING.md: how a release is made and published.
• CHANGELOG.md: what changed in each version.
• API reference: cargo doc --open, or docs.rs/safesweep.

License

Licensed under either of Apache License 2.0 or MIT license, at your option.