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(3) 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.

SEE ALSO

       CURLMOPT_NOTIFYFUNCTION(3), curl_multi_notify_disable(3), curl_multi_notify_enable(3)

libcurl                                            2025-11-07                             CURLMOPT_NOTIFYDATA(3)