From 9428dab28e0831f0d148911078ed79a715e7e857 Mon Sep 17 00:00:00 2001
From: Chris Greening <chris@cmgresearch.com>
Date: Wed, 1 Oct 2025 22:39:02 +0100
Subject: [PATCH] Allow sending of CTRL-C and CTRL-D

---
 src/components/ConsoleInput.tsx  | 42 ++++++++++++++++++++++++++++++--
 src/components/SerialConsole.tsx | 17 ++++++++++---
 2 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/src/components/ConsoleInput.tsx b/src/components/ConsoleInput.tsx
index c7ad430..a64bf5d 100644
--- a/src/components/ConsoleInput.tsx
+++ b/src/components/ConsoleInput.tsx
@@ -25,7 +25,29 @@ export default function ConsoleInput({ onSend, disabled = false }: ConsoleInputP
     setHistoryIndex(-1)
   }, [input, disabled, onSend, history])
 
+  const sendControlChar = useCallback((char: 'C' | 'D') => {
+    if (disabled) return
+    
+    // Send control character (Ctrl-C = 0x03, Ctrl-D = 0x04)
+    const code = char === 'C' ? 3 : 4
+    const controlChar = String.fromCharCode(code)
+    onSend(controlChar)
+  }, [disabled, onSend])
+
   const handleKeyDown = useCallback((e: KeyboardEvent<HTMLInputElement>) => {
+    // Handle Ctrl-C and Ctrl-D
+    if (e.ctrlKey || e.metaKey) {
+      if (e.key === 'c' || e.key === 'C') {
+        e.preventDefault()
+        sendControlChar('C')
+        return
+      } else if (e.key === 'd' || e.key === 'D') {
+        e.preventDefault()
+        sendControlChar('D')
+        return
+      }
+    }
+    
     if (e.key === 'Enter') {
       e.preventDefault()
       handleSend()
@@ -51,7 +73,7 @@ export default function ConsoleInput({ onSend, disabled = false }: ConsoleInputP
         }
       }
     }
-  }, [handleSend, history, historyIndex])
+  }, [handleSend, history, historyIndex, sendControlChar])
 
   return (
     <div className="flex gap-2 p-3 border-t border-gray-200 dark:border-neutral-800 bg-white dark:bg-neutral-950">
@@ -61,10 +83,26 @@ export default function ConsoleInput({ onSend, disabled = false }: ConsoleInputP
         value={input}
         onChange={(e) => setInput(e.target.value)}
         onKeyDown={handleKeyDown}
-        placeholder={disabled ? "Not connected" : "Type command and press Enter..."}
+        placeholder={disabled ? "Not connected" : "Type command and press Enter (Ctrl-C, Ctrl-D supported)..."}
         disabled={disabled}
         className="flex-1 px-3 py-2 text-sm border border-gray-300 dark:border-neutral-700 rounded-md bg-white dark:bg-neutral-900 text-gray-900 dark:text-neutral-100 placeholder-gray-400 dark:placeholder-neutral-500 focus:outline-none focus:ring-2 focus:ring-blue-500 dark:focus:ring-blue-400 disabled:opacity-50 disabled:cursor-not-allowed"
       />
+      <button
+        onClick={() => sendControlChar('C')}
+        disabled={disabled}
+        title="Send Ctrl-C (interrupt)"
+        className="px-3 py-2 text-sm font-medium text-white bg-orange-600 hover:bg-orange-700 dark:bg-orange-500 dark:hover:bg-orange-600 rounded-md transition-colors disabled:opacity-50 disabled:cursor-not-allowed disabled:hover:bg-orange-600 dark:disabled:hover:bg-orange-500"
+      >
+        ^C
+      </button>
+      <button
+        onClick={() => sendControlChar('D')}
+        disabled={disabled}
+        title="Send Ctrl-D (EOF)"
+        className="px-3 py-2 text-sm font-medium text-white bg-purple-600 hover:bg-purple-700 dark:bg-purple-500 dark:hover:bg-purple-600 rounded-md transition-colors disabled:opacity-50 disabled:cursor-not-allowed disabled:hover:bg-purple-600 dark:disabled:hover:bg-purple-500"
+      >
+        ^D
+      </button>
       <button
         onClick={handleSend}
         disabled={!input.trim() || disabled}
diff --git a/src/components/SerialConsole.tsx b/src/components/SerialConsole.tsx
index 19e76a0..263cfa7 100644
--- a/src/components/SerialConsole.tsx
+++ b/src/components/SerialConsole.tsx
@@ -17,11 +17,20 @@ export default function SerialConsole({ isConnected, onSendMessage }: SerialCons
 
   const handleSendMessage = useCallback(async (message: string) => {
     try {
-      // Add newline to message if not present
-      const messageToSend = message.endsWith('\n') ? message : message + '\n'
+      // Check if message is a control character (ASCII 0-31)
+      const isControlChar = message.length === 1 && message.charCodeAt(0) < 32
       
-      // Log outgoing message
-      addOutgoing(message)
+      // Add newline to message if not present (unless it's a control character)
+      const messageToSend = isControlChar ? message : (message.endsWith('\n') ? message : message + '\n')
+      
+      // Log outgoing message with readable name for control chars
+      if (isControlChar) {
+        const code = message.charCodeAt(0)
+        const ctrlName = code === 3 ? '^C (ETX)' : code === 4 ? '^D (EOT)' : `^${String.fromCharCode(64 + code)}`
+        addOutgoing(ctrlName)
+      } else {
+        addOutgoing(message)
+      }
       
       // Send via serial
       await onSendMessage(messageToSend)