CURLOPT_STDERR(3)          Library Functions Manual          CURLOPT_STDERR(3)

NAME
       CURLOPT_STDERR - redirect stderr to another stream

SYNOPSIS
       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_STDERR, FILE *stream);

DESCRIPTION
       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 work-around is to instead use
       CURLOPT_DEBUGFUNCTION(3).

DEFAULT
       stderr

PROTOCOLS
       This functionality affects all supported protocols

EXAMPLE
       int main(void)
       {
         CURL *curl = curl_easy_init();
         FILE *filep = fopen("dump", "wb");
         if(curl) {
           curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
           curl_easy_setopt(curl, CURLOPT_STDERR, filep);

           curl_easy_perform(curl);
         }
       }

AVAILABILITY
       Added in curl 7.1

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).

SEE ALSO
       CURLOPT_DEBUGFUNCTION(3), CURLOPT_NOPROGRESS(3), CURLOPT_VERBOSE(3)

libcurl                           2026-03-11                 CURLOPT_STDERR(3)