curl / libcurl / API / curl_multi_setopt / CURLMOPT_NOTIFYDATA

CURLMOPT_NOTIFYDATA explained

Name

CURLMOPT_NOTIFYDATA - custom pointer passed to the notification callback

Synopsis

#include <curl/curl.h>
 
CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_NOTIFYDATA, void *pointer);

Description

A data pointer to pass to the notification callback set with the CURLMOPT_NOTIFYFUNCTION option.

This pointer is not touched by libcurl but is only passed in as the notification callback's clientp argument.

Default

NULL

Protocols

This functionality affects all supported protocols

Example

struct priv {
  void *ours;
};
 
static void notify_cb(CURLM *multi, unsigned int notification,
                      CURL *easy, void *notifyp)
{
  struct priv *p = notifyp;
  printf("my ptr: %p\n", p->ours);
  /* ... */
}
 
int main(void)
{
  struct priv setup;
  CURLM *multi = curl_multi_init();
  /* ... use socket callback and custom pointer */
  curl_multi_setopt(multi, CURLMOPT_NOTIFYFUNCTION, notify_cb);
  curl_multi_setopt(multi, CURLMOPT_NOTIFYDATA, &setup);
  curl_multi_notify_enable(multi, CURLMNOTIFY_INFO_READ);
}

Availability

Added in curl 8.17.0

Return value

Returns CURLM_OK.