Merge pull request #95279 from kgremban/nov7-40520

C tutorial code improvements

Author: PRMerger12

articles/iot-edge/tutorial-c-module-windows.md

@@ -132,7 +132,7 @@ The default module code receives messages on an input queue and passes them alon
       )
       ```
 
-   3. Add **my_parson** to the list of libraries in the **target_link_libraries** section of the CMakeLists.txt file.
+   3. Add `my_parson` to the list of libraries in the **target_link_libraries** section of the CMakeLists.txt file.
 
    4. Save the **CMakeLists.txt** file.
 
@@ -172,6 +172,14 @@ The default module code receives messages on an input queue and passes them alon
 4. Find the `InputQueue1Callback` function, and replace the whole function with the following code. This function implements the actual messaging filter. When a message is received, it checks whether the reported temperature exceeds the threshold. If yes, then it forwards the message through its output queue. If not, then it ignores the message. 
 
     ```c
+    static unsigned char *bytearray_to_str(const unsigned char *buffer, size_t len)
+    {
+        unsigned char *ret = (unsigned char *)malloc(len + 1);
+        memcpy(ret, buffer, len);
+        ret[len] = '\0';
+        return ret;
+    }
+
     static IOTHUBMESSAGE_DISPOSITION_RESULT InputQueue1Callback(IOTHUB_MESSAGE_HANDLE message, void* userContextCallback)
     {
         IOTHUBMESSAGE_DISPOSITION_RESULT result;
@@ -181,7 +189,10 @@ The default module code receives messages on an input queue and passes them alon
         unsigned const char* messageBody;
         size_t contentSize;
 
-        if (IoTHubMessage_GetByteArray(message, &messageBody, &contentSize) != IOTHUB_MESSAGE_OK)
+        if (IoTHubMessage_GetByteArray(message, &messageBody, &contentSize) == IOTHUB_MESSAGE_OK)
+        {
+            messageBody = bytearray_to_str(messageBody, contentSize);
+        } else
         {
             messageBody = "<null>";
         }

articles/iot-edge/tutorial-c-module.md

@@ -7,7 +7,7 @@ author: shizn
 manager: philmea
 
 ms.author: xshi
-ms.date: 08/23/2019
+ms.date: 11/07/2019
 ms.topic: tutorial
 ms.service: iot-edge
 ms.custom: "mvc, seodec18"
@@ -112,7 +112,7 @@ The default module code receives messages on an input queue and passes them alon
       )
       ```
 
-   3. Add **my_parson** to the list of libraries in the **target_link_libraries** function of CMakeLists.txt.
+   3. Add `my_parson` to the list of libraries in the **target_link_libraries** function of CMakeLists.txt.
 
    4. Save the **CMakeLists.txt** file.
 
@@ -152,6 +152,14 @@ The default module code receives messages on an input queue and passes them alon
 1. Replace the entire `InputQueue1Callback` function with the following code. This function implements the actual messaging filter. When a message is received, it checks whether the reported temperature exceeds the threshold. If yes, then it forwards the message through its output queue. If not, then it ignores the message. 
 
     ```c
+    static unsigned char *bytearray_to_str(const unsigned char *buffer, size_t len)
+    {
+        unsigned char *ret = (unsigned char *)malloc(len + 1);
+        memcpy(ret, buffer, len);
+        ret[len] = '\0';
+        return ret;
+    }
+
     static IOTHUBMESSAGE_DISPOSITION_RESULT InputQueue1Callback(IOTHUB_MESSAGE_HANDLE message, void* userContextCallback)
     {
         IOTHUBMESSAGE_DISPOSITION_RESULT result;
@@ -161,7 +169,10 @@ The default module code receives messages on an input queue and passes them alon
         unsigned const char* messageBody;
         size_t contentSize;
 
-        if (IoTHubMessage_GetByteArray(message, &messageBody, &contentSize) != IOTHUB_MESSAGE_OK)
+        if (IoTHubMessage_GetByteArray(message, &messageBody, &contentSize) == IOTHUB_MESSAGE_OK)
+        {
+            messageBody = bytearray_to_str(messageBody, contentSize);
+        } else
         {
             messageBody = "<null>";
         }