Claude Code: finding an old session by what it did, and telling if it is still live

To find a past session by its work, grep ~/.claude/projects for rare terms from that work rather than a broad regex: a pattern like 'freed N GB' found nothing, while a specific path name it had touched found the transcript at once. Project directories start with a dash because the path is encoded, so grep -rl ... | xargs ls fails with unrecognized option; loop with while read -r f and use -- instead. To check whether the session is still running, search ~/.claude/sessions/*.json for its sessionId, since each live process has a file there with pid, sessionId and name. If there is no match, it cannot be messaged, but claude -p --resume <id> "..." continues it with its history. Without a terminal, permission prompts cannot be answered, so tell it to report denied commands rather than work around them.