GNU Awk 5.4.0 released

Version5.4.0 of GNU awk(gawk) has been released. This is a major release with a change ingawk's default regular-expression matcher: it now uses MinRXas the default regular-expression engine.

This matcher is fully POSIX compliant, which the current GNU matchersare not. In particular it follows POSIX rules for finding the longestleftmost submatches. It is also more strict as to regular expressionsyntax, but primarily in a few corner cases that normal, correct,regular expression usage should not encounter.

Because regular expression matching is such a fundamental part ofawk/gawk, the original GNU matchers are still included in gawk. In orderto use them, give a value to the GAWK_GNU_MATCHERS environment variablebefore invoking gawk.

[...] The original GNU matchers will eventually be removed fromgawk. So, please take the time to notice and report any issues in theMinRX matcher, so that they can be ironed out sooner rather than later.

See the release announcement for additional changes.