gawk: add real pattern-processing workflows

Formula/gawk.rb

@@ -0,0 +1,89 @@
+require (Tap.fetch("automattic", "kandelo-homebrew").path/"Kandelo/formula_support/kandelo_formula_support").to_s
+
+class Gawk < Formula
+  include KandeloFormulaSupport
+
+  desc "GNU pattern scanning and processing language for Kandelo"
+  homepage "https://www.gnu.org/software/gawk/"
+  url "https://ftpmirror.gnu.org/gnu/gawk/gawk-5.3.0.tar.xz"
+  mirror "https://ftp.gnu.org/gnu/gawk/gawk-5.3.0.tar.xz"
+  sha256 "ca9c16d3d11d0ff8c69d79dc0b47267e1329a69b39b799895604ed447d3ca90b"
+  license "GPL-3.0-or-later"
+
+  skip_clean "bin/gawk"
+
+  def install
+    kandelo_require_arch!("wasm32")
+
+    guest_prefix = "/home/linuxbrew/.linuxbrew"
+    instrumented = buildpath/"gawk.instrumented"
+    kandelo_wasm_build do |root|
+      # The SDK site owns target facts; these probes are specific to gnulib and gawk.
+      ENV["gl_cv_func_strerror_0_works"] = "yes"
+      ENV["ac_cv_func_GetSystemTimeAsFileTime"] = "no"
+
+      system kandelo_configure, *kandelo_std_configure_args,
+        "--disable-nls",
+        "--disable-extensions",
+        "--without-readline",
+        "--without-mpfr",
+        "--datadir=#{guest_prefix}/share",
+        "--libdir=#{guest_prefix}/lib",
+        "--disable-dependency-tracking"
+      system "make", "-j#{ENV.make_jobs}"
+      system "#{root}/scripts/run-wasm-fork-instrument.sh", buildpath/"gawk", "-o", instrumented
+    end
+
+    kandelo_install_bin(buildpath, "gawk.instrumented", "gawk")
+    man1.install buildpath/"doc/gawk.1"
+  end
+
+  test do
+    assert_match(/GNU Awk 5\.3\.0$/, kandelo_run_wasm(bin/"gawk", ["--version"]))
+
+    (testpath/"sales.csv").write <<~CSV
+      region,amount
+      east,7
+      west,3
+      east,5
+    CSV
+    aggregate = <<~AWK
+      BEGIN { FS = ","; OFS = ":" }
+      NR > 1 { total[$1] += $2; count[$1]++ }
+      END {
+        print "east", total["east"], count["east"]
+        print "west", total["west"], count["west"]
+      }
+    AWK
+    assert_equal "east:12:2\nwest:3:1\n",
+      kandelo_run_wasm(
+        bin/"gawk", [aggregate, "sales.csv"], env: { "KERNEL_CWD" => testpath }
+      )
+
+    extensions = <<~'AWK'
+      BEGIN {
+        match("alpha42", /([a-z]+)([0-9]+)/, capture)
+        print capture[1], capture[2]
+        print gensub(/([a-z]+)([0-9]+)/, "\\2-\\1", 1, "beta17")
+      }
+    AWK
+    assert_equal "alpha 42\n17-beta\n", kandelo_run_wasm(bin/"gawk", [extensions])
+
+    (testpath/"first.txt").write("a\nb\n")
+    (testpath/"second.txt").write("c\n")
+    assert_equal "1:1:a\n1:2:b\n2:1:c\n",
+      kandelo_run_wasm(
+        bin/"gawk",
+        ['{ print ARGIND ":" FNR ":" $0 }', "first.txt", "second.txt"],
+        env: { "KERNEL_CWD" => testpath },
+      )
+
+    missing = kandelo_run_wasm(
+      bin/"gawk", ["{ print }", "missing.txt"],
+      env:             { "KERNEL_CWD" => testpath },
+      merge_stderr:    true,
+      expected_status: 2
+    )
+    assert_match(/missing\.txt.*No such file or directory/, missing)
+  end
+end

README.md

@@ -35,7 +35,8 @@ Current migration controls and pilots include:
 - `dash`, the dependency-free POSIX shell with instrumented subprocess support;
 - `make`, GNU dependency-driven build automation using the tap's POSIX shell;
 - `ed`, the conforming line editor and restricted editor required by patch workflows;
-- `m4`, the GNU macro processor with process-executing builtins backed by the tap's Dash shell.
+- `m4`, the GNU macro processor with process-executing builtins backed by the tap's Dash shell;
+- `gawk`, GNU's pattern scanning and text-processing language.
 
 The SDK is not yet a Homebrew dependency. Trusted builds supply an
 `HOMEBREW_KANDELO_ROOT` checkout containing the SDK, sysroot, kernel, and Node