feat(awk): run gawk, mawk and nawk as the awk builtin

crates/bashkit/docs/compatibility.md

@@ -73,7 +73,7 @@ for sandbox security reasons. See the compliance spec for details.
 | `grep` | `-i`, `-v`, `-c`, `-n`, `-E`, `-q` | Pattern matching |
 | `rg` | `-i/-S/-s`, `-n/-N`, `--column`, `-b/--byte-offset`, `--vimgrep`, basic `--json`, `--stats`, `--null`, `-c`, `--count-matches`, `--include-zero`, `-l`, `--files-with-matches`, `--files-without-match`, `--files`, `-F`, `-w`, `-x`, `-a/--text`, `--binary`, `-m`, `-M/--max-columns`, `--max-columns-preview`, `--max-depth`, `-A`, `-B`, `-C`, separator flags, `--heading/--no-heading`, `--sort/--sortr`, `--path-separator`, `-g/--glob`, `--ignore-file`, `.ignore`/`.gitignore`, `--no-ignore*`, `--require-git/--no-require-git`, `-u/--unrestricted`, `--messages/--no-messages`, `-t/--type`, `-T/--type-not`, `--type-add`, `--type-clear`, `--type-list`, `--hidden/--no-hidden`, `-o`, `-q`, `-e`, `-f`, `-E/--encoding` (`auto`, `none`, UTF-8, UTF-16LE/BE), `-r`, `--passthru`, `--trim`, `-H/-I`, `--no-config`, `--line-buffered`, `--block-buffered`, `--mmap/--no-mmap`, `-P/--pcre2`, `--no-pcre2`, `--engine`, `--auto-hybrid-regex`, `--no-auto-hybrid-regex`, `--help`, `--version` | Recursive ripgrep-style search |
 | `sed` | `s///[gpiImMN w]`, `y`, `d`, `D`, `p`, `P`, `n`, `N`, `q[N]`, `Q[N]`, `=`, `l[N]`, `z`, `F`, `a`, `i`, `c`, `r`, `R`, `w`, `W`, `h/H/g/G/x`, `b`/`t`/`T`/`:label`, `{}`, `#`/`#n`; addresses `N`, `$`, `/re/[IM]`, `\cREc`, `first~step`, `a,b`, `a,+N`, `a,~N`, `0,/re/`, `!`; options `-n -e -f -i[SUF] -E/-r -s -z -l N -u --` and long forms | Stream editing; one stream across operands unless `-s`/`-i` |
-| `awk` | `'{print}'`, `-F`, `-v`, loops, arrays, increment, ternary | Text processing |
+| `awk` (also `gawk`, `mawk`, `nawk`) | `'{print}'`, `-F`, `-v`, loops, arrays, increment, ternary | Text processing |
 | `jq` | `.field`, `.[n]`, pipes, file args, `-r`, `-c`, `-n`, `-s`, `-S`, `-e`, `-j`, `-f`/`--from-file`, `--tab`, `--arg`, `--argjson`, `-V`, combined flags | JSON processing |
 | `sleep` | `N`, `N.N` | Pause execution (max 60s) |
 | `head` | `-n N`, `-N` | First N lines (default 10) |

crates/bashkit/src/interpreter/mod.rs

@@ -1634,6 +1634,9 @@ impl Interpreter {
             "grep" => Grep,
             "sed" => Sed,
             "awk" => Awk,
+            "gawk" => Awk,
+            "mawk" => Awk,
+            "nawk" => Awk,
             "head" => Head,
             "tail" => Tail,
             "sort" => Sort,

crates/bashkit/tests/spec_cases/bash/awk-aliases.test.sh

@@ -0,0 +1,33 @@
+# gawk, mawk and nawk run the awk builtin, so scripts that call a
+# specific implementation by name keep working.
+
+### mawk_runs_awk
+echo "a b" | mawk '{print $2}'
+### expect
+b
+### end
+
+### gawk_runs_awk
+### bash_diff: gawk is not installed on the reference host
+echo "a b" | gawk '{print toupper($1)}'
+echo x | gawk '{print gensub(/x/, "y", "g")}'
+### expect
+A
+y
+### end
+
+### nawk_runs_awk
+### bash_diff: nawk is not installed on the reference host
+nawk 'BEGIN{print 1+2}'
+### expect
+3
+### end
+
+### awk_aliases_resolve
+### bash_diff: gawk/nawk are not installed on the reference host
+for c in gawk mawk nawk; do type -t "$c"; done
+### expect
+file
+file
+file
+### end

knowledge/log.md

@@ -2,6 +2,7 @@
 
 ## 2026-10-07
 
+* **Feature**: `gawk`, `mawk` and `nawk` run the awk builtin (same engine, including gawk extensions it already had such as `gensub`, `toupper`). Gap telemetry showed agents probing `gawk` by name. `--version` still identifies as bashkit awk.
 * **Fix**: `tar -P`/`--absolute-names` keeps the leading `/` (no notice), `-T FILE`/`--files-from` reads member names (blank lines skipped, `-` is stdin), and `--` ends options. `ls` implements the quoting styles: `-b`/`--escape`, `-N`, `-Q`, `--quoting-style=literal|escape|c|shell|shell-always|shell-escape|shell-escape-always` (GNU rules, including `"it's"` and headers left unescaped under `-b`); `locale`/`clocale` still report not implemented. Found by gap telemetry.
 * **Fix**: Arithmetic assigns to array elements. `((a[i]++))`, `((c[$k]+=3))`, `((a[2]=5))`, `((--a[0]))`, `let a[1]++` and `$((c[x]--))` read and write the element (indexed subscripts are arithmetic and accept negative indexes; associative keys are literal, quotes dropped as in `((c["x y"]++))`). Before, the update was lost or written to a scalar. Writes go through the budgeted `${a[i]:=v}` writer, so array memory limits still apply. Found by gap telemetry.
 * **Fix**: Gaps from the replayed agent calls: `set -n` / `set -o noexec` now stops running the rest of the script, as in bash (it was accepted and ignored); `find -ls` prints GNU's `ls -dils` layout; `tar -c` stores absolute paths without the leading `/` (with GNU's `Removing leading` notice) and `tar -cv` lists members on stdout unless the archive goes to stdout. Specs: `set-noexec.test.sh`, `find.test.sh`, `tar.test.sh`.

knowledge/status/builtins.json

@@ -285,6 +285,10 @@
       "feature": null,
       "name": "free"
     },
+    {
+      "feature": null,
+      "name": "gawk"
+    },
     {
       "feature": null,
       "name": "getconf"
@@ -429,6 +433,10 @@
       "feature": null,
       "name": "mapfile"
     },
+    {
+      "feature": null,
+      "name": "mawk"
+    },
     {
       "feature": null,
       "name": "md5sum"
@@ -457,6 +465,10 @@
       "feature": null,
       "name": "nano"
     },
+    {
+      "feature": null,
+      "name": "nawk"
+    },
     {
       "feature": null,
       "name": "nice"
@@ -882,5 +894,5 @@
       "name": "zip"
     }
   ],
-  "count": 220
+  "count": 223
 }