CURLOPT_PROGRESSDATA explained

Name

CURLOPT_PROGRESSDATA - pointer passed to the progress callback

Synopsis

#include <curl/curl.h>
 
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROGRESSDATA, void *pointer);

Description

Pass a pointer that is untouched by libcurl and passed as the first argument in the progress callback set with CURLOPT_PROGRESSFUNCTION.

Default

NULL

Protocols

This functionality affects all supported protocols

Example

struct progress {
  char *private;
  size_t size;
};
 
static size_t progress_callback(void *clientp,
                                double dltotal,
                                double dlnow,
                                double ultotal,
                                double ulnow)
{
  struct progress *memory = clientp;
  printf("private: %p\n", memory->private);
 
  /* use the values */
 
  return 0; /* all is good */
}
 
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    struct progress data;
 
    /* pass struct to callback  */
    curl_easy_setopt(curl, CURLOPT_PROGRESSDATA, &data);
    curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, progress_callback);
 
    curl_easy_perform(curl);
  }
}

Availability

Added in curl 7.1

Return value

curl_easy_setopt returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors.