CURLMOPT_SOCKETFUNCTION(3)				     curl_multi_setopt options					CURLMOPT_SOCKETFUNCTION(3)

NAME

       CURLMOPT_SOCKETFUNCTION - callback informed about what to wait for

SYNOPSIS

       #include <curl/curl.h>

       int socket_callback(CURL *easy,	    /* easy handle */
			   curl_socket_t s, /* socket */
			   int what,	    /* describes the socket */
			   void *userp,     /* private callback pointer */
			   void *socketp);  /* private socket pointer */

       CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_SOCKETFUNCTION, socket_callback);

DESCRIPTION

       Pass a pointer to your callback function, which should match the prototype shown above.

       When  the  curl_multi_socket_action(3)  function  runs,	it informs the application about updates in the socket (file descriptor) status by
       doing none, one, or multiple calls to the socket_callback. The callback gets status updates with changes since the previous time the  call-
       back  was called.  If the given callback pointer is NULL, no callback will be called. Set the callback's userp argument with CURLMOPT_SOCK-
       ETDATA(3).  See curl_multi_socket_action(3) for more details on how the callback is used and should work.

       The what parameter informs the callback on the status of the given socket. It can hold one of these values:

       CURL_POLL_IN
	      Wait for incoming data. For the socket to become readable.

       CURL_POLL_OUT
	      Wait for outgoing data. For the socket to become writable.

       CURL_POLL_INOUT
	      Wait for incoming and outgoing data. For the socket to become readable or writable.

       CURL_POLL_REMOVE
	      The specified socket/file descriptor is no longer used by libcurl.

DEFAULT

       NULL (no callback)

PROTOCOLS

       All

EXAMPLE

       TODO

AVAILABILITY

       Added in 7.15.4

RETURN VALUE

       Returns CURLM_OK.

SEE ALSO

       CURLMOPT_SOCKETDATA(3), curl_multi_socket_action(3), CURLMOPT_TIMERFUNCTION(3)

libcurl 7.39.0							    3 Nov 2016						CURLMOPT_SOCKETFUNCTION(3)