Azure IoT hub C sdk blob upload example possible without low level API?

Question

I'm trying the iothub_client/samples/iothub_client_sample_upload_to_blob from the Azure IoT hub C sdk. It compiles and works fine if I use the low-level API. But as soon as I switch to the convenience layer (as the documentation in the app's file suggests), I get an error:

/home/user/workspaceMisc/azure-iot-sdk-c/iothub_client/samples/iothub_client_sample_upload_to_blob/iothub_client_sample_upload_to_blob.c: In function ‘iothub_client_sample_upload_to_blob_run’:
/home/user/workspaceMisc/azure-iot-sdk-c/iothub_client/samples/iothub_client_sample_upload_to_blob/iothub_client_sample_upload_to_blob.c:77:25: error: implicit declaration of function ‘IoTHubClient_UploadToBlob’ [-Werror=implicit-function-declaration]
                     if (IoTHubClient_UploadToBlob(iotHubClientHandle, "subdir/hello_world.txt", (const unsigned char*)HELLO_WORLD, sizeof(HELLO_WORLD) - 1) != IOTHUB_CLIENT_OK)
                         ^
cc1: all warnings being treated as errors
iothub_client/samples/iothub_client_sample_upload_to_blob/CMakeFiles/iothub_client_sample_upload_to_blob.dir/build.make:62: recipe for target 'iothub_client/samples/iothub_client_sample_upload_to_blob/CMakeFiles/iothub_client_sample_upload_to_blob.dir/iothub_client_sample_upload_to_blob.c.o' failed

How can I upload a file with the convenience layer instead of the low level layer? Is it possible at all?

I'm using Ubuntu 16.04, gcc 5.4.0 and the latest clone of the SDK.

Answer 1

Actually the function name is IoTHubClient_UploadToBlobAsync, you need add Async postfix. And there is needed additional two parameters: iotHubClientFileUploadCallback and context. This document is somewhat misleading.

So you can call this function like this:

IoTHubClient_UploadToBlobAsync(iotHubClientHandle, "subdir/hello_world.txt", (const unsigned char*)HELLO_WORLD, sizeof(HELLO_WORLD) - 1, NULL, NULL);