From 7ab35bbdef8881e1adca779dbc3d8f59e2dec94e Mon Sep 17 00:00:00 2001
From: Adolfo Delorenzo <adelorenzo@oe74.net>
Date: Mon, 29 Jul 2024 13:27:56 -0600
Subject: [PATCH] 2024-07-29 -

---
 wifi_switch.sh | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100755 wifi_switch.sh

diff --git a/wifi_switch.sh b/wifi_switch.sh
new file mode 100755
index 0000000..d4c9ff9
--- /dev/null
+++ b/wifi_switch.sh
@@ -0,0 +1,44 @@
+#!/bin/bash
+
+# Configuration
+WIFI_INTERFACE="wlan0"
+MODEM_INTERFACE="wwan0"
+CHECK_INTERVAL=10  # Check every 60 seconds
+
+# Function to check Wi-Fi connection
+check_wifi() {
+    if iwconfig "$WIFI_INTERFACE" | grep -q "ESSID:off/any"; then
+        return 1  # Wi-Fi is not connected
+    else
+        return 0  # Wi-Fi is connected
+    fi
+}
+
+# Function to enable 4G modem
+enable_4g() {
+    echo "Wi-Fi disconnected. Enabling 4G modem..."
+    sudo ifconfig "$MODEM_INTERFACE" up
+    sudo dhclient "$MODEM_INTERFACE"
+}
+
+# Function to disable 4G modem
+disable_4g() {
+    echo "Wi-Fi connected. Disabling 4G modem..."
+    sudo ifconfig "$MODEM_INTERFACE" down
+}
+
+# Main loop
+while true; do
+    if check_wifi; then
+        echo "Wi-Fi is connected."
+        if ifconfig "$MODEM_INTERFACE" | grep -q "UP"; then
+            disable_4g
+        fi
+    else
+        echo "Wi-Fi is disconnected."
+        if ! ifconfig "$MODEM_INTERFACE" | grep -q "UP"; then
+            enable_4g
+        fi
+    fi
+    sleep "$CHECK_INTERVAL"
+done