CURLOPT_STDERR (3) - Linux Manuals
CURLOPT_STDERR: redirect stderr to another stream
NAME
CURLOPT_STDERR - redirect stderr to another streamSYNOPSIS
#include <curl/curl.h>CURLcode curl_easy_setopt(CURL *handle, CURLOPT_STDERR, FILE *stream);
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_STDERR, FILE *stream);