jq: filter as positional arg, file args appended, pipeline-safe.
expect: pipes script via printf '%s' $'...' | expect -.
bc: pipes via printf '%s' $'...' | bc -ql (quiet + math library).
All three use ANSI-C quoting consistently.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>