rars

A Rust implementation of RAR.

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Current Status

rars covers the RAR lineage from early RE~^ archives through RAR 7, compression and decompression. It's getting faster, and kinda works.

Rust API

Use the rars crate for Rust applications and libraries. Since 0.4, the lower-level rars-format, rars-codec, rars-crypto, rars-crc32, and rars-recovery crates are folded into rars; those standalone crates ended at 0.3.x. Applications should depend on rars, and command-line installs should use rars-cli.

CLI

Inspect, test, and extract archives:

rars info archive.rar
rars test archive.rar
rars x archive.rar out/

Create archives with specific RAR generation:

rars a --format rar29 archive.rar files...
rars a --format rar50 --solid --auto-filter archive.rar files...
rars a --format rar70 --store --volume-size 10m archive.part1.rar files...

The writer supports stored and compressed members, split volumes, passwords, header encryption where implemented, comments, RARVM filters, RAR5 quick-open records, and supported recovery records. Run rars --help for more info.

RAR 5 and RAR 7 archives are written in a single pass without being held in memory, so the peak stays flat whatever the inputs weigh. Members compress into temporary files under --temp-dir, and --memory-limit (256MB by default) bounds the working set: raise it to compress more blocks at once, which on a machine with many cores is what limits throughput. The number of --threads defaults to your core count.

RAR 5 and RAR 7 look for a data filter by default, which is worth around 6% on executables and costs compression time rather than memory; --no-filter turns it off, and solid archives do not use one because they share a dictionary across members. Choosing a filter, and comparing candidate settings at --level 5, both need a whole member in memory, and fall back to streaming without them when the budget is too small to allow it. Per-file comments, PPMd and the RAR 1.3-4.x formats still assemble archives in memory; the CLI warns before doing that with a large input.

Python bindings

Python bindings are published to pypi, so you can pip install rars. To build locally, it's maturin develop.

Development

Run the test suite:

cargo test --workspace --all-targets

Generate a local coverage report:

rustup component add llvm-tools-preview
./scripts/coverage.py

The script prints a line-coverage summary, saves it to target/coverage/summary.txt, and writes HTML output to target/coverage/html/library/index.html and target/coverage/html/cli/index.html.