c - 通过 HTTP 请求上传文件到 Google Drive (C)

Question

我想使用 C 编程将文件上传到 Google 云端硬盘。

我遵循了 Google's tutorial 的以下说明& libcurl example .

POST https://www.googleapis.com/upload/drive/v3/files?uploadType=media HTTP/1.1
Content-Type: image/jpeg
Content-Length: [NUMBER_OF_BYTES_IN_FILE]
Authorization: Bearer [YOUR_AUTH_TOKEN]

[JPEG_DATA]

但我不知道我应该用[JPEG_DATA]替换什么。它是指文件名吗？

对于 Content-Length: [NUMBER_OF_BYTES_IN_FILE]，这是否意味着我应该用我的计算机显示的准确文件大小替换它？

到目前为止我写的代码:

curl_handle = curl_easy_init();

struct curl_slist *header = NULL;

/* Content-Type: image/jpeg */
header = curl_slist_append(header, "Content-Type: image/jpeg");

不确定要在下面的 [NUMBER_OF_BYTES_IN_FILE] 中放入什么

/* Content-Length: [NUMBER_OF_BYTES_IN_FILE] */
header = curl_slist_append(header, "Content-Length:[NUMBER_OF_BYTES_IN_FILE]");

/* Authorization: Bearer [YOUR_AUTH_TOKEN] */
char auth[200];
strcat(auth, "Authorization: Bearer ");
strcat(auth, access_token);

header = curl_slist_append(header, auth);

curl_easy_setopt(curl_handle, CURLOPT_HTTPHEADER, header);

/* POST https://www.googleapis.com/upload/drive/v3/files?uploadType=media HTTP/1.1 */
curl_easy_setopt(curl_handle, CURLOPT_URL, "https://www.googleapis.com/upload/drive/v3/files");

curl_easy_setopt(curl_handle, CURLOPT_POSTFIELDS, "uploadType=media");

curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);

curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void *)&chunk);

curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, "libcurl-agent/1.0");

res = curl_easy_perform(curl_handle);

/* Print response */
if(res != CURLE_OK) {
    fprintf(stderr, "curl_easy_perform() failed: %s\n",
    curl_easy_strerror(res4));
}

else {
    printf("%s\n", chunk.memory);
}

curl_easy_cleanup(curl_handle);

free(chunk.memory);

谢谢!

Answer 1

[JPEG_DATA] 将是文件的确切内容，一个字节接一个字节。 [NUMBER_OF_BYTES_IN_FILE] 是文件的大小，巧合的是 [JPEG_DATA] 中的字节数。

可以看到post-callback.c查看如何将负载添加到 POST 请求，以及 httpput.c查看如何从文件中增量读取数据。