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.TH CURLOPT_HEADEROPT 3 "September 26, 2023" "ibcurl 8.4.0" libcurl

.SH NAME
CURLOPT_HEADEROPT \- send HTTP headers to both proxy and host or separately
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HEADEROPT, long bitmask);
.fi
.SH DESCRIPTION
Pass a long that is a bitmask of options of how to deal with headers. The two
mutually exclusive options are:

\fBCURLHEADER_UNIFIED\fP - the headers specified in
\fICURLOPT_HTTPHEADER(3)\fP are used in requests both to servers and
proxies. With this option enabled, \fICURLOPT_PROXYHEADER(3)\fP does not have
any effect.

\fBCURLHEADER_SEPARATE\fP - makes \fICURLOPT_HTTPHEADER(3)\fP headers only get
sent to a server and not to a proxy. Proxy headers must be set with
\fICURLOPT_PROXYHEADER(3)\fP to get used. Note that if a non-CONNECT request
is sent to a proxy, libcurl sends both server headers and proxy headers. When
doing CONNECT, libcurl sends \fICURLOPT_PROXYHEADER(3)\fP headers only to the
proxy and then \fICURLOPT_HTTPHEADER(3)\fP headers only to the server.
.SH DEFAULT
CURLHEADER_SEPARATE (changed in 7.42.1, used CURLHEADER_UNIFIED before then)
.SH PROTOCOLS
HTTP
.SH EXAMPLE
.nf
CURL *curl = curl_easy_init();
if(curl) {
  CURLcode ret;
  struct curl_slist *list;
  list = curl_slist_append(NULL, "Shoesize: 10");
  list = curl_slist_append(list, "Accept:");
  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
  curl_easy_setopt(curl, CURLOPT_PROXY, "http://localhost:8080");
  curl_easy_setopt(curl, CURLOPT_HTTPHEADER, list);

  /* HTTPS over a proxy makes a separate CONNECT to the proxy, so tell
     libcurl to not send the custom headers to the proxy. Keep them
     separate! */
  curl_easy_setopt(curl, CURLOPT_HEADEROPT, CURLHEADER_SEPARATE);
  ret = curl_easy_perform(curl);
  curl_slist_free_all(list);
  curl_easy_cleanup(curl);
}
.fi
.SH AVAILABILITY
Added in 7.37.0
.SH RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
.SH "SEE ALSO"
.BR CURLOPT_HTTPHEADER (3),
.BR CURLOPT_PROXYHEADER (3)