CURLOPT_HEADERDATA(3)

1CURLOPT_HEADERDATA(3)      curl_easy_setopt options      CURLOPT_HEADERDATA(3)
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NAME

6       CURLOPT_HEADERDATA - pointer to pass to header callback
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SYNOPSIS

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

15       Pass a pointer to be used to write the header part of the received data
16       to.
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18       If   CURLOPT_WRITEFUNCTION(3)  or  CURLOPT_HEADERFUNCTION(3)  is  used,
19       pointer will be passed in to the respective callback.
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21       If neither of those options are set, pointer must be a valid FILE * and
22       it will be used by a plain fwrite() to write headers to.
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DEFAULT

25       NULL
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PROTOCOLS

28       All
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EXAMPLE

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

60       Always
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RETURN VALUE

63       Returns CURLE_OK
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