Creating libcurl http post form

Question

How do i create a curl_form e.g to do a post on stackoverflow?

If i look in source of question form page, I see

<label for="display-name">Name</label>
                <input id="display-name" name="display-name" type="text" size="30" maxlength="30" value="" tabindex="105">
            </div>
            <div>
                <label for="m-address">Email</label>
                <input id="m-address" name="m-address" type="text" size="40" maxlength="100" value="" tabindex="106">
                <span class="edit-field-overlay">never shown</span>
            </div>
            <div>
                <label for="home-page">Home Page</label>
                <input id="home-page" name="home-page" type="text" size="40" maxlength="200" value="" tabindex="107">
            </div>

How do i set these parameters for a curl_httppost structure?

Answer 1

From the libcurl sample: http://curl.haxx.se/libcurl/c/postit2.html

You don't manipulate curl_httppost directly. You'd write something like this to set the m-address field.

CURL *curl;
CURLcode res;

struct curl_httppost *formpost=NULL;
struct curl_httppost *lastptr=NULL;
struct curl_slist *headerlist=NULL;
static const char buf[] = "Expect:";

curl_global_init(CURL_GLOBAL_ALL);

curl_formadd(&formpost,
             &lastptr,
             CURLFORM_COPYNAME, "m-address",
             CURLFORM_COPYCONTENTS, "[email protected]",
             CURLFORM_END);

curl = curl_easy_init();
headerlist = curl_slist_append(headerlist, buf);
if(curl) {
    /* what URL that receives this POST */ 
    curl_easy_setopt(curl, CURLOPT_URL, "http://stackoverflow.com/someurl");
    if ( (argc == 2) && (!strcmp(argv[1], "noexpectheader")) )
      /* only disable 100-continue header if explicitly requested */ 
      curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headerlist);
    curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
    res = curl_easy_perform(curl);

    /* always cleanup */ 
    curl_easy_cleanup(curl);

    /* then cleanup the formpost chain */ 
    curl_formfree(formpost);
    /* free slist */ 
    curl_slist_free_all (headerlist);