---

c: Copyright (C) Daniel Stenberg, <daniel.se>, et al. SPDX-License-Identifier: curl Title: CURLOPT_TRAILERDATA Section: 3 Source: libcurl See-also:

• CURLOPT_TRAILERFUNCTION (3)
• CURLOPT_WRITEFUNCTION (3)

---

NAME

CURLOPT_TRAILERDATA - pointer passed to trailing headers callback

SYNOPSIS

#include <curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TRAILERDATA, void *userdata);

DESCRIPTION

Data pointer to be passed to the HTTP trailer callback function.

DEFAULT

NULL

PROTOCOLS

HTTP

EXAMPLE

struct MyData {
  void *custom;
};

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    struct MyData data;
    curl_easy_setopt(curl, CURLOPT_TRAILERDATA, &data);
  }
}

AVAILABILITY

This option was added in curl 7.64.0 and is present if HTTP support is enabled

RETURN VALUE

Returns CURLE_OK.