Fix KEEP_PCAP not working with sudo

- Add --keep-pcap command-line flag that works with sudo
- Environment variable KEEP_PCAP still works with 'sudo -E'
- Usage: sudo ./test_monitor_tshark.sh wlan0 36 10 --keep-pcap
- Or: KEEP_PCAP=1 sudo -E ./test_monitor_tshark.sh wlan0 36 10

Co-authored-by: Cursor <cursoragent@cursor.com>

test_monitor_tshark.sh

@@ -1,12 +1,31 @@
 #!/bin/bash
 # Test script to verify monitor mode works with tshark
-# Usage: ./test_monitor_tshark.sh [interface] [channel] [duration_seconds]
+# Usage: ./test_monitor_tshark.sh [interface] [channel] [duration_seconds] [--keep-pcap]
+# Or: KEEP_PCAP=1 sudo -E ./test_monitor_tshark.sh [interface] [channel] [duration_seconds]
 
 set -e
 
-INTERFACE="${1:-wlan0}"
-CHANNEL="${2:-36}"
-DURATION="${3:-10}"  # Default 10 seconds, minimum 1 second
+# Parse arguments
+KEEP_PCAP_FLAG=""
+ARGS=()
+for arg in "$@"; do
+    if [ "$arg" = "--keep-pcap" ] || [ "$arg" = "-k" ]; then
+        KEEP_PCAP_FLAG="1"
+    else
+        ARGS+=("$arg")
+    fi
+done
+
+INTERFACE="${ARGS[0]:-wlan0}"
+CHANNEL="${ARGS[1]:-36}"
+DURATION="${ARGS[2]:-10}"  # Default 10 seconds, minimum 1 second
+
+# Check for KEEP_PCAP environment variable or flag
+if [ -n "$KEEP_PCAP_FLAG" ]; then
+    KEEP_PCAP="1"
+elif [ -z "${KEEP_PCAP:-}" ]; then
+    KEEP_PCAP=""
+fi
 
 # Ensure minimum 1 second
 if [ "$DURATION" -lt 1 ]; then
@@ -189,11 +208,12 @@ CAPTURE_OUTPUT=$(tshark -q -r "$TEMP_PCAP" -n -T fields \
     2>/dev/null || true)
 
 # Clean up temp file (unless KEEP_PCAP is set)
-if [ -z "${KEEP_PCAP:-}" ]; then
+if [ -z "$KEEP_PCAP" ]; then
     echo "Cleaning up temporary pcap file: $TEMP_PCAP"
     rm -f "$TEMP_PCAP"
 else
     echo "Keeping temporary pcap file: $TEMP_PCAP"
+    echo "  (Use: tshark -r $TEMP_PCAP to analyze)"
 fi
 
 # Force output flush