Piped stdin never reaches Claude (docker exec/run missing -i)

[alanbem]

Problem

The non-interactive / print-mode paths run Claude without attaching stdin:

• Persistent container, existing: exec docker exec -u claude -w "$HOST_PATH" "$container_name" claude ... (dclaude:1820)
• Persistent container, fresh: same pattern (dclaude:2043)
• Ephemeral: TTY flags are derived from [[ -t 0 ]], so piped stdin (not a TTY) yields no -i either

So the canonical scripting integration silently gets empty stdin:

git diff | dclaude -p "review this diff"     # Claude sees no input
cat error.log | dclaude -p "explain"          # same

The TTY-detection table in CLAUDE.md describes exactly these scenarios, but the implementation conflates "stdin is not a TTY" (skip -t, skip tmux) with "don't attach stdin at all" (skip -i).

Fix

-i (attach stdin) and -t (allocate TTY) are independent. Stdin should be attached whenever it's a TTY or a pipe/redirect — effectively always for docker exec/docker run in these paths. Only -t should depend on TTY detection:

docker exec -i $([[ "$STDOUT_IS_TTY" == "true" ]] && echo -t) ...

(Only fully detached/background use would want to drop -i, which dclaude doesn't have.)

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Found during a full-project code review.