uutils AWK is a WIP, cross-platform reimplementation of GNU AWK (a.k.a. gawk) in Rust.

uutils AWK aims to be a drop-in replacement for gawk. Differences with GNU are treated as bugs.

Our key objectives include:

• Matching GNU's output (stdout and error code) exactly
• Better error messages
• Best-in-class memory safety
• Improved performance
• Providing comprehensive internationalization support (UTF-8, etc.)
• Extensions when relevant

uutils AWK aims to work on as many platforms as possible, to be able to use the same utils on Linux, macOS, *BSD, Windows, WASI and other platforms. This ensures, for example, that scripts can be easily transferred between platforms.

• Rust (cargo, rustc)

uutils AWK follows Rust's release channels and is tested against stable, beta and nightly. The minimum supported Rust version at the moment is the previous stable version, that is, 1.95.0 at the time of writing.

Check out #16.

Track compatibility against GNU awk by running the upstream gawk testsuite against our Rust binary. Rather than reimplement gawk's test harness, we drive gawk's own (GPL) test Makefile with make check AWK=<wrapper>, where the wrapper execs our awk — the gawk sources are fetched fresh at test time and never copied into this repo.

# Fetch the gawk testsuite (one-time setup)
mkdir -p ../gnu.awk && (cd ../gnu.awk && bash ../awk/util/fetch-gnu.sh)

# Run compatibility tests
./util/run-gnu-testsuite.sh

# Verbose mode shows the diff for each failing test
./util/run-gnu-testsuite.sh -v

# Generate JSON results for CI
./util/run-gnu-testsuite.sh --json-output results.json

The harness builds our awk, runs gawk's make check with a wrapper named gawk, and classifies each test the way gawk's own pass-fail target does: a leftover _<name> file is a failure, its absence a pass, and tests that never run (group-skipped because of missing locales, MPFR, or shared-library support) are reported as skipped.

cargo test --workspace

To contribute to uutils AWK, please see CONTRIBUTING.

uutils AWK is licensed under either the MIT License or the Apache v2.0 License - see the LICENSE-MIT, LICENSE-APACHE files for details.

GNU AWK is licensed under the GPL 3.0 or later.