merge: testing → main (reconcile 2-week divergence)

scripts/bus/sub.py

@@ -0,0 +1,38 @@
+#!/usr/bin/env python3
+"""Subscribe to a pattern on the local DECNET bus and print events.
+
+Usage: scripts/bus/sub.py 'topology.>'
+       scripts/bus/sub.py 'system.bus.health'
+       DECNET_BUS_SOCKET=/tmp/decnet-bus.sock scripts/bus/sub.py 'topology.*.status'
+"""
+from __future__ import annotations
+
+import asyncio
+import os
+import sys
+
+from decnet.bus.unix_client import UnixSocketBus
+
+
+async def main(pattern: str) -> None:
+    sock = os.environ.get("DECNET_BUS_SOCKET", "/tmp/decnet-bus.sock")
+    client = UnixSocketBus(sock, client_name="scripts-sub")
+    await client.connect()
+    sub = client.subscribe(pattern)
+    print(f"sub: pattern={pattern!r} socket={sock}  (Ctrl-C to stop)", flush=True)
+    try:
+        async with sub:
+            async for ev in sub:
+                print(f"{ev.topic}  type={ev.type!r}  payload={ev.payload}", flush=True)
+    finally:
+        await client.close()
+
+
+if __name__ == "__main__":
+    if len(sys.argv) != 2:
+        print("Usage: sub.py <pattern>", file=sys.stderr)
+        sys.exit(2)
+    try:
+        asyncio.run(main(sys.argv[1]))
+    except KeyboardInterrupt:
+        pass