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;
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);
}
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 2026-06-09 CURLOPT_STDERR(3)
curl 8.20.0 - Generated Wed Jun 10 16:46:19 CDT 2026