CURLMOPT_TIMERDATA(3)

CURLMOPT_TIMERDATA3

Custom pointer to pass to timer callback

Usage

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

Overview

A data pointer to pass to the timer callback set with the CURLMOPT_TIMERFUNCTION(3) option.

This pointer is not touched by libcurl but is only be passed in to the timer callback's clientp argument.

Default

NULL

Protocols

This functionality affects all supported protocols

Examples

struct priv {
  void *custom;
};
static int timerfunc(CURLM *multi, long timeout_ms, void *clientp)
{
  struct priv *mydata = clientp;
  printf("our ptr: %p\n", mydata->custom);
  if(timeout_ms >= 0) {
    /* this is the new single timeout to wait for */
  }
  else {
    /* delete the timeout, nothing to wait for now */
  }
  return 0;
}
int main(void)
{
  struct priv mydata;
  CURLM *multi = curl_multi_init();
  curl_multi_setopt(multi, CURLMOPT_TIMERFUNCTION, timerfunc);
  curl_multi_setopt(multi, CURLMOPT_TIMERDATA, &mydata);
}

Return value

curl_multi_setopt(3) returns a CURLMcode indicating success or error.

CURLM_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).

Releases

6 releases since Debian 9 (Stretch); the text changed 5 times.

  1. 9
  2. 10
  3. 11
  4. 12
  5. 13
  6. Arch

Availability

Added in curl 7.16.0

From curl 8.23.0-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.