apps: Add GPSD app.

Once enabled, running a GPSD client (for example, cgps) on the node can obtain the current position and motion information of the node.

Change-Id: Ib88424cc7fe07898de5b37c1699e170bf89e58a5
diff --git a/examples/wifi/adhoc_gpsd.py b/examples/wifi/adhoc_gpsd.py
new file mode 100644
index 0000000..4d52c83
--- /dev/null
+++ b/examples/wifi/adhoc_gpsd.py
@@ -0,0 +1,67 @@
+# -*- Mode:python; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+#
+# Copyright (C) 2015-2025, The University of Memphis,
+#                          Arizona Board of Regents,
+#                          Regents of the University of California.
+#
+# This file is part of Mini-NDN.
+# See AUTHORS.md for a complete list of Mini-NDN authors and contributors.
+#
+# Mini-NDN is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Mini-NDN is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Mini-NDN, e.g., in COPYING.md file.
+# If not, see <http://www.gnu.org/licenses/>.
+
+from time import sleep
+from mininet.log import setLogLevel, info
+from minindn.wifi.minindnwifi import MinindnAdhoc
+from minindn.util import MiniNDNWifiCLI
+from minindn.apps.app_manager import AppManager
+from minindn.apps.nfd import Nfd
+from minindn.apps.gpsd import Gpsd
+# This experiment uses the topology defined in adhoc-topology.conf and
+# is intended to test whether app Gpsd can work with Mini-NDN.
+def runExperiment():
+    setLogLevel('info')
+
+    info("Starting network\n")
+    ndnwifi = MinindnAdhoc()
+    a = ndnwifi.net["sta1"]
+    b = ndnwifi.net["sta2"]
+
+    ndnwifi.start()
+
+    info("Starting gpsd\n")
+
+    AppManager(ndnwifi, ndnwifi.net.stations, Gpsd, lat=35.11908, lon=-89.93778, altitude=200, update_interval=0.2)
+
+    info("Starting NFD\n")
+    AppManager(ndnwifi, ndnwifi.net.stations, Nfd)
+
+    sleep(1)
+
+    # run cgps in the Xterm terminal to check gps info
+    for node in [a,b]:
+        node.cmd(f"xterm -T '{node.name}' -e 'cgps' &")
+
+    # Start the CLI
+    MiniNDNWifiCLI(ndnwifi.net)
+
+    # Stop the network and clean up
+    ndnwifi.stop()
+    ndnwifi.cleanUp()
+
+if __name__ == '__main__':
+    try:
+        runExperiment()
+    except Exception as e:
+        MinindnAdhoc.handleException()