Miscellaneous Improvements

.github/codeql/codeql-config.yml

@@ -0,0 +1,18 @@
+name: ffpdf CodeQL config
+
+# security-extended: broader security queries than the default suite; the right
+# bar for a parser that eats untrusted input.
+queries:
+  - uses: security-extended
+
+query-filters:
+  # cpp/path-injection flags every fopen() of a path the user passed on the
+  # command line. For a CLI whose entire job is reading the files named in
+  # argv, that is the interface, not a vulnerability -- there is no trust
+  # boundary between "user input" and "the file the user asked to open".
+  # This rule fired on ~every PR that adds a file-opening path (dismissed on
+  # alerts 4-8, 10-15), so it is excluded here rather than dismissed each time.
+  # If ffpdf ever accepts a path from genuinely untrusted input (e.g. a field
+  # value that names an external file), revisit this exclusion.
+  - exclude:
+      id: cpp/path-injection

.github/workflows/codeql.yml

@@ -27,9 +27,9 @@ jobs:
         with:
           languages: c-cpp
           build-mode: manual
-          # security-extended: broader security queries than the default suite;
-          # right bar for a parser that eats untrusted input.
-          queries: security-extended
+          # Query suite (security-extended) and the cpp/path-injection exclusion
+          # live in the config file.
+          config-file: ./.github/codeql/codeql-config.yml
 
       - name: Build
         run: |

.gitignore

@@ -6,5 +6,6 @@ fuzz-findings/
 FUTURE_WORK.md
 filled.pdf
 answers.fdf
+values.json
 out/
 row.fdf

CHANGELOG.md

@@ -9,11 +9,42 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
-- `fields` command: list every fillable field as JSON, with names, types,
-  current values (UTF-16 values decoded to UTF-8), choice options and
+- `fields` command: list every fillable field as JSON, with names,
+  human-readable labels (`/TU`), types, current values (UTF-16 values decoded
+  to UTF-8), `required`/`readonly`/`maxlen` constraints, choice options and
   combo/multi-select flags, and checkbox on-state names. A machine-readable
   companion to `fdf-extract` for scripts and AI agents.
 
+- `fill --json` writes a machine-readable result to stdout (the `updated`
+  and `not_found` field names and their counts; requires `-o` for the PDF),
+  and `fill --strict` exits 3 if any FDF field did not match a form field.
+  For scripts and AI agents that need to verify a fill by exit code or
+  parsed output rather than scraping stderr.
+- Documented that multi-select choice fields are filled with an array,
+  `/V [(opt1) (opt2)]`.
+- `fill` now accepts a **JSON** values object as well as an FDF, auto-detected
+  from the file's content, and takes the PDF and values file in **either
+  order** (`-` reads the values from stdin). JSON values may be a string, a
+  multi-select array, a number, or a boolean (to check/clear a checkbox). This
+  closes the discover-then-fill loop in one format for agents. The documented
+  argument order is now `fill <pdf> <values>`.
+- Radio-button groups: `fields` now reports the group's valid option names,
+  and `fill` sets the selected button's appearance state (`/AS`) so the choice
+  renders, not just the group value.
+
+### Changed
+
+- `fill` now exits **2** (and writes no output) when no field in the input
+  matched the form. A no-op fill — e.g. every field name misspelled — is
+  treated as a failure by default rather than a silent success, so callers
+  need no flag to detect it. `--flatten` is exempt (it removes the form even
+  with no new values), and a partial match (some fields land) still exits 0
+  unless `--strict` is given.
+
+- A value longer than a text field's `/MaxLen` is now truncated to fit (on a
+  UTF-8 character boundary) with a warning, instead of writing an over-length,
+  non-conformant value; `fill --json` lists such fields under `truncated`.
+
 ### Fixed
 
 - ffpdf can now re-read PDFs it filled. Streams without a `/Filter` (legal

Makefile

@@ -157,7 +157,7 @@ docs/demo.gif: docs/demo.tape docs/demo-form.pdf $(TARGET)
 	  { echo "vhs not found -- install it (and ttyd + ffmpeg): https://github.com/charmbracelet/vhs"; exit 1; }
 	vhs docs/demo.tape
 
-docs/demo-batch.gif: docs/demo-batch.tape docs/demo-template.fdf docs/demo-customers.csv docs/demo-form.pdf $(TARGET)
+docs/demo-batch.gif: docs/demo-batch.tape docs/demo-template.json docs/demo-customers.csv docs/demo-form.pdf $(TARGET)
 	@command -v vhs >/dev/null || \
 	  { echo "vhs not found -- install it (and ttyd + ffmpeg): https://github.com/charmbracelet/vhs"; exit 1; }
 	vhs docs/demo-batch.tape