Merge branch 'master' of codeberg.org:ET-Kiel/tk102gpx

netcat does not cut it.  The loop accepts at most one connection at each
time.  There will eb overlap when the mobile cell changes.

This script accepts up to 100 connections and merges whatever comes in.

tk102cat.py

@@ -0,0 +1,54 @@
+#! /usr/bin/python3
+
+import os, sys, time, select, socket, getopt, fcntl
+
+port = 10201
+out = sys.stdout.buffer
+files = []
+timeout = None
+
+def logger(s):
+    print(s, file=sys.stderr)
+
+oo,files = getopt.getopt(sys.argv[1:], "p:", ("port=",))
+
+for o,v in oo:
+    if o=="-p" or o=="--port":
+        port = int(v,0)
+
+poll = select.poll()
+
+sockets = {}
+
+sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+sock.bind(("", port))
+sock.listen(2)
+poll.register(sock, select.POLLIN)
+logger("listening on port %d, socket fd %d" % (port,sock.fileno()))
+
+while True:
+    c = poll.poll(timeout)
+    for fd, ev in c:
+        if fd==sock.fileno():
+            s = sock.accept()
+            logger("connection from %s" % repr(s[1]))
+            if len(sockets) > 99:
+                logger("too many connections %s" % repr(sockets))
+                s[0].send("too many connections, good bye")
+                s[0].close()
+            else:
+                sockets[s[0].fileno()] = s
+                poll.register(s[0], select.POLLIN | select.POLLHUP | select.POLLRDHUP)
+        elif fd in sockets:
+            so = sockets[fd][0]
+            if ev & select.POLLIN:
+                d = so.recv(4096, socket.MSG_DONTWAIT)
+                if d:
+                    out.write(d)
+                    out.flush()
+            if ev & (select.POLLHUP | select.POLLRDHUP):
+                logger("closing connection from %s" % repr(sockets[fd][1]))
+                del sockets[fd]
+                poll.unregister(fd)
+                so.close()