Expose foreground process group PID on Unix#918
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Add a `foregroundPid` getter that returns `tcgetpgrp(fd)` on the pty master fd, exposing the pid of the foreground process group attached to the pty (or `undefined` on failure). This is the same syscall the existing `pty_getproc` already invokes internally to resolve the foreground process *name* — it's just returning the pid instead of throwing it away. Useful for callers that need to identify which process is currently in the foreground of a terminal (e.g. to detect that an agent like claude-code is running, where the process name resolves to "node"). Cross-platform: works on both Linux and macOS via tcgetpgrp(3). Not exposed on Windows (no equivalent ConPTY concept).
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Unix terminals can now report the foreground process group PID directly.
processalready resolves the foreground process name by callingtcgetpgrp(3)internally; this exposes the same process-group id asforegroundPidfor callers that need to identify the active foreground program without reverse-mapping from a process title.The property is optional on the public
IPtytype because Windows/ConPTY does not expose an equivalent concept. On Unix it returnsnumber | undefined, matching the native lookup behavior when the pty has already exited ortcgetpgrpfails.Verification
npm run buildnpm test -- --grep "foreground process group"npm teston the same macOS host currently reaches 23 passing tests and then times out in the existingshould return the name of the sub processtest; the new foregroundPid test passes before that unrelated timeout.Generated by Codex (model
gpt-5).