interpreter: implement RS regexp and blank-line record splitting by Franklin-Qi · Pull Request #133 · uutils/awk

Franklin-Qi · 2026-10-09T08:50:58Z

Wire RT as a builtin and finish the missing RS modes (multi-char regexp and RS="") so record boundaries and RT match gawk.

Closes: #124

github-actions · 2026-10-09T08:53:38Z

GNU awk testsuite comparison:

Test results comparison:
  Current:   TOTAL: 666 / PASSED: 97 / FAILED: 471 / SKIPPED: 98
  Reference: TOTAL: 666 / PASSED: 90 / FAILED: 478 / SKIPPED: 98

Changes from main branch:
  TOTAL: +0
  PASSED: +7
  FAILED: -7

New test failures (1):
  - rscompat

Test improvements (8):
  + fpat8
  + fsnul1
  + leadnl
  + nlinstr
  + nulrsend
  + onlynl
  + rs
  + rsnul1nl

github-actions · 2026-10-09T09:14:55Z

GNU awk testsuite comparison:

Test results comparison:
  Current:   TOTAL: 666 / PASSED: 98 / FAILED: 470 / SKIPPED: 98
  Reference: TOTAL: 666 / PASSED: 90 / FAILED: 478 / SKIPPED: 98

Changes from main branch:
  TOTAL: +0
  PASSED: +8
  FAILED: -8

Test improvements (8):
  + fpat8
  + fsnul1
  + leadnl
  + nlinstr
  + nulrsend
  + onlynl
  + rs
  + rsnul1nl

sylvestre · 2026-10-09T19:55:27Z

+            // Single character, or POSIX: only the first character of `RS`.
+            self.read_record_until_char(c, reader)
+        } else {
+            // Non-empty but not valid UTF-8 start: treat as regexp bytes.


in Posix mode this still takes the regexp path, is that intended?

sylvestre · 2026-10-09T19:56:32Z

+}
+
+#[test]
+fn rs_empty_match_does_not_split_characters() {


please also add tests for RT with RS = "": leading newlines, several blank lines between records, and trailing newlines at EOF

Okay, I have add tests.

Wire RT as a builtin and finish the missing RS modes (multi-char regexp and RS=""). Cache the RS automaton, keep reading when a match touches the buffer end, and consume rs_leftover when RS switches mid-file. Closes: uutils#124

github-actions · 2026-10-10T10:29:18Z

GNU awk testsuite comparison:

Test results comparison:
  Current:   TOTAL: 666 / PASSED: 97 / FAILED: 471 / SKIPPED: 98
  Reference: TOTAL: 666 / PASSED: 90 / FAILED: 478 / SKIPPED: 98

Changes from main branch:
  TOTAL: +0
  PASSED: +7
  FAILED: -7

New test failures (1):
  - rscompat

Test improvements (8):
  + fpat8
  + fsnul1
  + leadnl
  + nlinstr
  + nulrsend
  + onlynl
  + rs
  + rsnul1nl