curl http libcurl 功能使用

/*
 * This example shows a HTTP PUT operation. PUTs a file given as a command
 * line argument to the URL also given on the command line.
 *
 * This example also uses its own read callback.
 *
 * Here's an article on how to setup a PUT handler for Apache:
 * http://www.apacheweek.com/features/put
 */

static size_t read_callback(void *ptr, size_t size, size_t nmemb, void *stream)
{
  size_t retcode;
  curl_off_t nread;

  /* in real-world cases, this would probably get this data differently
     as this fread() stuff is exactly what the library already would do
     by default internally */
  retcode = fread(ptr, size, nmemb, (FILE*)stream);

  nread = (curl_off_t)retcode;

  fprintf(stderr, "*** We read %" CURL_FORMAT_CURL_OFF_T
          " bytes from file\n", nread);

  return retcode;
}

//http协议上传
void fileUploadHttp()
{
  CURL *curl;
  CURLcode res;
  FILE * hd_src;
  struct stat file_info;

  QString locale = ui->lineEdit_path->text();
  char *file = locale.toLatin1().data();
  QFileInfo fileInfo(locale);
  QString fileName = fileInfo.fileName();
  QString remote = "http://www.example.com/upload.php?filename=" + fileName;
  char *remote_url = remote.toLatin1().data(); //服务器路径

  /* get the file size of the local file */
  stat(file, &file_info);

  /* get a FILE * of the same file, could also be made with
     fdopen() from the previous descriptor, but hey this is just
     an example! */
  hd_src = fopen(file, "rb");

  /* In windows, this will init the winsock stuff */
  curl_global_init(CURL_GLOBAL_ALL);

  /* get a curl handle */
  curl = curl_easy_init();
  if(curl) {
    /* we want to use our own read function */
    curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_callback);

    /* enable uploading */
    curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);

    /* HTTP PUT please */
    curl_easy_setopt(curl, CURLOPT_PUT, 1L);

    /* specify target URL, and note that this URL should include a file
       name, not only a directory */
    curl_easy_setopt(curl, CURLOPT_URL, remote_url);

    /* now specify which file to upload */
    curl_easy_setopt(curl, CURLOPT_READDATA, hd_src);

    /* provide the size of the upload, we specicially typecast the value
       to curl_off_t since we must be sure to use the correct data size */
    curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE,
                     (curl_off_t)file_info.st_size);

    /* Now run off and do what you've been told! */
    res = curl_easy_perform(curl);
    /* Check for errors */
    if(res != CURLE_OK)
      fprintf(stderr, "curl_easy_perform() failed: %s\n",
              curl_easy_strerror(res));

    /* always cleanup */
    curl_easy_cleanup(curl);
  }
  fclose(hd_src); /* close the local file */

  curl_global_cleanup();
}