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Install

Fastmash runs on Linux x86-64 and on Windows through WSL2. macOS on Apple Silicon is under development for 0.2.0. The published 0.1.0 release has Linux artifacts only. It installs next to GNU datamash without changing it. Native Windows is outside the current product scope.

Quick install

curl -fsSL https://fastmash.io/install.sh | sh

The script downloads the latest release, checks its checksum and installs fastmash and fastmash-sort-supervisor into ~/.local/bin. Set FASTMASH_INSTALL_DIR to install elsewhere, or FASTMASH_VERSION for a specific release.

On Linux the script uses sha256sum. A macOS archive uses the system shasum -a 256, and installs only fastmash. Rust and GNU coreutils are not required to install an archive. Download and checksum failures leave an existing installation unchanged.

The script checks the download against its published SHA-256 checksum. For a stronger check that the archive was built by this project’s release workflow, download it by hand and verify its GitHub build attestation:

gh attestation verify fastmash-v0.1.0-x86_64-unknown-linux-gnu.tar.gz --repo pederbe/fastmash

Prebuilt binary, by hand

Download a release from the releases page, check it and copy the two programs into a directory on your PATH:

version=0.1.0
name=fastmash-v$version-x86_64-unknown-linux-gnu
curl -LO https://github.com/pederbe/fastmash/releases/download/v$version/$name.tar.gz
curl -LO https://github.com/pederbe/fastmash/releases/download/v$version/$name.tar.gz.sha256
sha256sum -c $name.tar.gz.sha256
tar -xzf $name.tar.gz
mkdir -p ~/.local/bin
cp $name/fastmash $name/fastmash-sort-supervisor ~/.local/bin/

Replace 0.1.0 with the release you want, and keep fastmash and fastmash-sort-supervisor from the same release in the same directory. If the supervisor is missing, some large sorted jobs are slower; if it comes from another release, the sorted jobs that use it stop with a message saying so.

With Cargo

If you have a Rust toolchain:

cargo install --locked fastmash

With cargo-binstall, Cargo downloads the prebuilt release binaries instead of compiling:

cargo binstall fastmash

These commands install published versions. Version 0.1.0 does not contain the native macOS development changes.

Homebrew on Linux

With Homebrew on Linux x86-64:

brew install pederbe/tap/fastmash

The maintainer’s tap builds the published source with its locked Rust dependencies. It installs both programs and their licenses and notices. Rust and Python are build dependencies; these source builds do not carry the performance qualification of the downloadable binaries.

Run brew test pederbe/tap/fastmash to check the installation. The test includes the optional system-sort route and needs Linux 5.11 or later with coreutils at /usr/bin/sort. Older kernels can use Fastmash’s built-in sorting. Remove the package with brew uninstall pederbe/tap/fastmash.

Native macOS development archive

For Apple Silicon with macOS 15 or later, the native development workflow builds one archive with a macOS 15 deployment target and tests those same bytes on macOS 15 and 26. It contains fastmash, licenses and build provenance; there is no macOS Sort supervisor. These CI artifacts are development builds, not a published macOS release, and expire according to the run’s retention.

Choose a successful native macOS workflow run and download its macos-archive artifact. With the GitHub CLI, use gh run download RUN_ID --repo pederbe/fastmash --name macos-archive in an empty directory. Replace RUN_ID with that run’s identifier. Confirm the run’s source revision and native installation results before using its build.

Run this block in Bash; invoke bash first if using Fish. It stops on a failed checksum before changing an existing installation:

bash -eu <<'EOF'
version=$(cat archive-version.txt)
name=fastmash-v$version-aarch64-apple-darwin
shasum -a 256 -c "$name.tar.gz.sha256"
tar -xzf "$name.tar.gz"
(cd "$name" && shasum -a 256 -c binary.sha256)
cat "$name/build-provenance.txt"
mkdir -p ~/.local/bin
staging=$(mktemp -d "$HOME/.local/bin/.fastmash.XXXXXX")
trap 'rm -rf "$staging"' EXIT
cp "$name/fastmash" "$staging/fastmash"
chmod 755 "$staging/fastmash"
mv -f "$staging/fastmash" ~/.local/bin/fastmash
printf '1\n2\n' | ~/.local/bin/fastmash sum 1
EOF

The final command prints 3. The archive label includes the source revision and a macos-test suffix; --version reports the source’s current package version. The provenance labels the artifact as a development test build.

For a future published macOS archive, the quick installer selects aarch64-apple-darwin automatically and checks its SHA-256 file using the native checksum tool. The current release’s quick-install URL cannot yet deliver a macOS archive.

The archive is not Apple-notarized. Native CI records extended attributes, code-signing metadata and the assessment result for a terminal download, then executes the installed command without changing macOS security controls. Browser downloads can have different quarantine behavior and are outside these terminal checks. A checksum checks bytes, not Apple approval.

Debian and Ubuntu

curl -LO https://github.com/pederbe/fastmash/releases/download/v0.1.0/fastmash_0.1.0_amd64.deb
sudo apt install ./fastmash_0.1.0_amd64.deb

For Debian 10, Ubuntu 20.04 and newer. Remove it with sudo apt remove fastmash.

Fedora, RHEL and similar

sudo dnf install https://github.com/pederbe/fastmash/releases/download/v0.1.0/fastmash-0.1.0-1.x86_64.rpm

For Fedora, RHEL 8 and newer. Remove it with sudo dnf remove fastmash.

Check that it works

printf '1\t2\n3\t4\n' | fastmash sum 1 mean 2

This prints 4 and 3, separated by a tab. Next: the quick start.

On Windows

Install WSL2, then install Fastmash inside your Linux distribution as above. Keep your data in the Linux file system (such as your home directory) rather than under /mnt/c: it is much faster.

Uninstall

rm ~/.local/bin/fastmash
# On Linux, also remove the supervisor:
rm ~/.local/bin/fastmash-sort-supervisor
# or, if installed with Cargo or cargo-binstall:
cargo uninstall fastmash

Fastmash keeps no configuration files, caches or background services.

Building from source, verifying release archives and the full system requirements are described in System requirements.