NAME

       curl_easy_send - sends raw data over an "easy" connection

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_send(CURL *curl, const void *buffer,
                               size_t buflen, size_t *n);

DESCRIPTION

       This  function  sends  arbitrary  data  over  the  established  connection. You may use it
       together  with  curl_easy_recv(3)  to  implement  custom  protocols  using  libcurl.  This
       functionality can be particularly useful if you use proxies and/or SSL encryption: libcurl
       takes care of proxy negotiation and connection setup.

       buffer is a pointer to the data of length buflen that you want sent. The variable n points
       to receives the number of sent bytes.

       To   establish   the   connection,   set  CURLOPT_CONNECT_ONLY(3)  option  before  calling
       curl_easy_perform(3) or curl_multi_perform(3). Note that curl_easy_send(3) does  not  work
       on connections that were created without this option.

       The  call returns CURLE_AGAIN if it is not possible to send data right now - the socket is
       used in non-blocking mode internally. When CURLE_AGAIN is  returned,  use  your  operating
       system  facilities  like select(2) to wait until the socket is writable. The socket may be
       obtained using curl_easy_getinfo(3) with CURLINFO_ACTIVESOCKET(3).

       Furthermore if you wait on the socket and it tells you it is  writable,  curl_easy_send(3)
       may return CURLE_AGAIN if the only data that was sent was for internal SSL processing, and
       no other data could be sent.

PROTOCOLS

       This functionality affects all supported protocols

EXAMPLE

       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           CURLcode res;
           curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
           /* Do not do the transfer - only connect to host */
           curl_easy_setopt(curl, CURLOPT_CONNECT_ONLY, 1L);
           res = curl_easy_perform(curl);

           if(res == CURLE_OK) {
             long sockfd;
             size_t sent;
             /* Extract the socket from the curl handle - we need it for waiting. */
             res = curl_easy_getinfo(curl, CURLINFO_ACTIVESOCKET, &sockfd);

             /* send data */
             res = curl_easy_send(curl, "hello", 5, &sent);
           }
         }
       }

AVAILABILITY

       Added in curl 7.18.2

RETURN VALUE

       On success, returns CURLE_OK and stores the number of bytes actually sent  into  *n.  Note
       that this may be less than the amount you wanted to send.

       On failure, returns the appropriate error code.

       This  function  may return CURLE_AGAIN. In this case, use your operating system facilities
       to wait until the socket is writable, and retry.

       If there is no socket available to use from the previous transfer, this  function  returns
       CURLE_UNSUPPORTED_PROTOCOL.

SEE ALSO

       curl_easy_getinfo(3), curl_easy_perform(3), curl_easy_recv(3), curl_easy_setopt(3)