Fix test_monitor_tshark.sh to always show counters

- Add message that capture may take time
- Always display packet and PLCP counts
- Better parsing of tshark output
- Separate warnings/errors from packet data
- Show note if packets captured but no PLCP headers

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

test_monitor_tshark.sh

@@ -80,36 +80,35 @@ iw dev "$INTERFACE" info | grep -E "(type|channel)" || echo "Could not verify"
 # Check DLT with tshark (capture for 1 second)
 echo ""
 echo "Checking Data Link Type (1 second test capture)..."
-# First check if we can open the interface
+echo "(This may take up to 2 seconds if no packets are present)"
-DLT_CHECK=$(tshark -i "$INTERFACE" -T fields -e frame.number -c 0 2>&1 | head -1)
-if echo "$DLT_CHECK" | grep -q "Running as"; then
-    echo "$DLT_CHECK"
-fi
 
-# Use -c to limit packets and add immediate output, redirect stderr to see warnings
+# Use timeout with -c to limit packets and avoid hanging
-# Use a shorter timeout and limit packets to avoid hanging
+# Capture both stdout and stderr
-TEST_OUTPUT=$(timeout 2 tshark -i "$INTERFACE" -c 100 -T fields -e frame.number -e radiotap.present 2>&1 || echo "")
+TEST_OUTPUT=$(timeout 2 tshark -i "$INTERFACE" -c 100 -T fields -e frame.number -e radiotap.present 2>&1 || true)
-TEST_EXIT_CODE=$?
+TEST_EXIT_CODE=${PIPESTATUS[0]}
 
-# Show any warnings/errors from tshark
+# Show any warnings/errors from tshark (but not packet data)
-echo "$TEST_OUTPUT" | grep -E "(Running as|tshark:|Warning|Error)" || true
+echo "$TEST_OUTPUT" | grep -E "(Running as|tshark:|Warning|Error|Capturing)" || true
+
+# Count packets (lines starting with a number, excluding error messages)
+PACKET_LINES=$(echo "$TEST_OUTPUT" | grep -E '^[0-9]+' || true)
+PACKET_COUNT=$(echo "$PACKET_LINES" | wc -l || echo "0")
 
-# Count packets (lines starting with a number)
-PACKET_COUNT=$(echo "$TEST_OUTPUT" | grep -E '^[0-9]+' | wc -l || echo "0")
 # Count lines with both frame.number and radiotap.present (non-empty second field)
-PLCP_COUNT=$(echo "$TEST_OUTPUT" | awk -F'\t' 'NF >= 2 && $1 != "" && $2 != "" && $2 != "0" && $2 != "-" {count++} END {print count+0}' || echo "0")
+PLCP_COUNT=$(echo "$PACKET_LINES" | awk -F'\t' 'NF >= 2 && $1 != "" && $2 != "" && $2 != "0" && $2 != "-" {count++} END {print count+0}' || echo "0")
 
 # Show sample output
 if [ "$PACKET_COUNT" -gt 0 ]; then
     echo "Sample packets:"
-    echo "$TEST_OUTPUT" | grep -E '^[0-9]+' | head -3
+    echo "$PACKET_LINES" | head -3
 fi
 
-echo "Captured $PACKET_COUNT packet(s) in test capture"
+echo ""
-if [ "$PLCP_COUNT" -gt 0 ]; then
+echo "Test capture results:"
-    echo "PLCP headers: $PLCP_COUNT (radiotap present)"
+echo "  Packets captured: $PACKET_COUNT"
-else
+echo "  PLCP headers: $PLCP_COUNT"
-    echo "PLCP headers: 0 (no radiotap headers detected)"
+if [ "$PLCP_COUNT" -eq 0 ] && [ "$PACKET_COUNT" -gt 0 ]; then
+    echo "  Note: Packets captured but no radiotap headers (may be using DLT_IEEE802_11 instead of DLT_IEEE802_11_RADIO)"
 fi
 
 echo ""