CURLOPT_HTTPHEADER(3)					     curl_easy_setopt options					     CURLOPT_HTTPHEADER(3)

NAME

       CURLOPT_HTTPHEADER - set custom HTTP headers

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HTTPHEADER, struct curl_slist *headers);

DESCRIPTION

       Pass a pointer to a linked list of HTTP headers to pass to the server and/or proxy in your HTTP request. The same list can be used for both
       host and proxy requests!

       The linked list should be a fully valid list of struct curl_slist structs properly filled in. Use curl_slist_append(3) to create  the  list
       and curl_slist_free_all(3) to clean up an entire list. If you add a header that is otherwise generated and used by libcurl internally, your
       added one will be used instead. If you add a header with no content as in 'Accept:' (no data on the right side of the  colon),  the  inter-
       nally used header will get disabled. With this option you can add new headers, replace internal headers and remove internal headers. To add
       a header with no content (nothing to the right side of the colon), use the form 'MyHeader;' (note the ending semicolon).

       The headers included in the linked list must not be CRLF-terminated, because libcurl adds CRLF after each header item.  Failure	to  comply
       with this will result in strange bugs because the server will most likely ignore part of the headers you specified.

       The  first  line in a request (containing the method, usually a GET or POST) is not a header and cannot be replaced using this option. Only
       the lines following the request-line are headers. Adding this method line in this list of headers will only cause your request to  send	an
       invalid header. Use CURLOPT_CUSTOMREQUEST(3) to change the method.

       When this option is passed to curl_easy_setopt(3), libcurl will not copy the entire list so you must keep it around until you no longer use
       this handle for a transfer before you call curl_slist_free_all(3) on the list.

       Pass a NULL to this option to reset back to no custom headers.

       The most commonly replaced headers have "shortcuts" in the options CURLOPT_COOKIE(3), CURLOPT_USERAGENT(3) and CURLOPT_REFERER(3). We  rec-
       ommend using those.

       There's	an  alternative  option  that  sets  or  replaces  headers only for requests that are sent with CONNECT to a proxy: CURLOPT_PROXY-
       HEADER(3). Use CURLOPT_HEADEROPT(3) to control the behavior.

SECURITY CONCERNS

       By default, this option makes libcurl send the given headers in all HTTP requests done by this handle. You should therefore use this option
       with  caution  if  you  for example connect to the remote site using a proxy and a CONNECT request, you should to consider if that proxy is
       supposed to also get the headers. They may be private or otherwise sensitive to leak.

       Use CURLOPT_HEADEROPT(3) to make the headers only get sent to where you intend them to get sent.

DEFAULT

       NULL

PROTOCOLS

       HTTP

EXAMPLE

       CURL *curl = curl_easy_init();

       struct curl_slist *list = NULL;

       if(curl) {
	 curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");

	 list = curl_slist_append(list, "Shoesize: 10");
	 list = curl_slist_append(list, "Accept:");

	 curl_easy_setopt(curl, CURLOPT_HTTPHEADER, list);

	 curl_easy_perform(curl);

	 curl_slist_free_all(list); /* free the list again */
       }

AVAILABILITY

       As long as HTTP is enabled

RETURN VALUE

       Returns CURLE_OK if HTTP is supported, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO

       CURLOPT_CUSTOMREQUEST(3), CURLOPT_HEADEROPT(3), CURLOPT_PROXYHEADER(3), CURLOPT_HEADER(3)

libcurl 7.54.0							 February 03, 2016					     CURLOPT_HTTPHEADER(3)