onoffget to 1 to ask libcurl to include the headers in the write callback (
#CURLOPT_WRITEFUNCTION). This option is relevant for protocols that actually have headers or other meta-data (like HTTP and FTP).
When asking to get the headers passed to the same callback as the body, it is not possible to accurately separate them again without detailed knowledge about the protocol in use.
#CURLOPT_WRITEFUNCTION callback is limited to only ever
get a maximum of
#CURL_MAX_WRITE_SIZE bytes passed to it (16KB), while a
header can be longer and the
#CURLOPT_HEADERFUNCTION supports getting
called with headers up to
#CURL_MAX_HTTP_HEADER bytes big (100KB).
It is often better to use
#CURLOPT_HEADERFUNCTION to get the header
While named confusingly similar,
#CURLOPT_HTTPHEADER is used to get
custom HTTP headers!