CURLOPT_STDERR(3)

CURLOPT_STDERR3

Redirect stderr to another stream

Usage

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_STDERR, FILE *stream);

Overview

Pass a FILE * as parameter. Tell libcurl to use this stream instead of stderr when showing the progress meter and displaying CURLOPT_VERBOSE(3) data.

If you are using libcurl as a Windows DLL, this option causes an exception and a crash in the library since it cannot access a FILE * passed on from the application. A workaround is to instead use CURLOPT_DEBUGFUNCTION(3).

Default

stderr

Protocols

This functionality affects all supported protocols

Examples

int main(void)
{
  CURL *curl;
  FILE *filep = fopen("dump", "wb");
  if(!filep)
    return 1;
  curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
    curl_easy_setopt(curl, CURLOPT_STDERR, filep);
    result = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
  fclose(filep);
}

Return value

curl_easy_setopt(3) returns a CURLcode indicating success or error.

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

Releases

7 releases since Debian 8 (Jessie); the text changed 6 times.

  1. 8
  2. 9
  3. 10
  4. 11
  5. 12
  6. 13
  7. Arch

Availability

Added in curl 7.1

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