CURLOPT_HEADER - pass headers to the data stream
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HEADER, long onoff);
Pass the long value
onoff set to 1 to ask libcurl to include the headers
in the write callback (
CURLOPT_WRITEFUNCTION(3)). 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.
Further: the
CURLOPT_WRITEFUNCTION(3) 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(3) supports getting
called with headers up to
CURL_MAX_HTTP_HEADER bytes big (100KB).
It is often better to use
CURLOPT_HEADERFUNCTION(3) to get the header
data separately.
While named confusingly similar,
CURLOPT_HTTPHEADER(3) is used to set
custom HTTP headers!
0
Most
CURL *curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
curl_easy_setopt(curl, CURLOPT_HEADER, 1L);
curl_easy_perform(curl);
}
Provided in all libcurl versions.
Returns CURLE_OK.
CURLOPT_HEADERFUNCTION(3),
CURLOPT_HTTPHEADER(3),