CURLOPT_HEADERDATA(3)

1CURLOPT_HEADERDATA(3)      curl_easy_setopt options      CURLOPT_HEADERDATA(3)
2
3
4

NAME

6       CURLOPT_HEADERDATA - pointer to pass to header callback
7

SYNOPSIS

9       #include <curl/curl.h>
10
11       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HEADERDATA, void *pointer);
12

DESCRIPTION

14       Pass a pointer to be used to write the header part of the received data
15       to.
16
17       If  CURLOPT_WRITEFUNCTION(3)  or  CURLOPT_HEADERFUNCTION(3)  is   used,
18       pointer will be passed in to the respective callback.
19
20       If neither of those options are set, pointer must be a valid FILE * and
21       it will be used by a plain fwrite() to write headers to.
22
23       If you are using libcurl as a win32 DLL, you MUST use a  CURLOPT_WRITE‐
24       FUNCTION(3)  or CURLOPT_HEADERFUNCTION(3) if you set this option or you
25       will experience crashes.
26

DEFAULT

28       NULL
29

PROTOCOLS

31       All
32

EXAMPLE

34       struct my_info {
35         int shoesize;
36         char *secret;
37       };
38
39       static size_t header_callback(char *buffer, size_t size,
40                                     size_t nitems, void *userdata)
41       {
42         struct my_info *i = (struct my_info *)userdata;
43
44         /* now this callback can access the my_info struct */
45
46         return nitems * size;
47       }
48
49       CURL *curl = curl_easy_init();
50       if(curl) {
51         struct my_info my = { 10, "the cookies are in the cupboard" };
52         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
53
54         curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, header_callback);
55
56         /* pass in custom data to the callback */
57         curl_easy_setopt(curl, CURLOPT_HEADERDATA, &my);
58
59         curl_easy_perform(curl);
60       }
61

AVAILABILITY

63       Always
64

RETURN VALUE

66       Returns CURLE_OK
67