curlopt_sockoptfunction(3) [mojave man page]

CURLOPT_SOCKOPTFUNCTION(3)				     curl_easy_setopt options					CURLOPT_SOCKOPTFUNCTION(3)

NAME

       CURLOPT_SOCKOPTFUNCTION - set callback for setting socket options

SYNOPSIS

       #include <curl/curl.h>

       typedef enum  {
	 CURLSOCKTYPE_IPCXN,  /* socket created for a specific IP connection */
	 CURLSOCKTYPE_ACCEPT, /* socket created by accept() call */
	 CURLSOCKTYPE_LAST    /* never use */
       } curlsocktype;

       #define CURL_SOCKOPT_OK 0
       #define CURL_SOCKOPT_ERROR 1 /* causes libcurl to abort and return
				       CURLE_ABORTED_BY_CALLBACK */
       #define CURL_SOCKOPT_ALREADY_CONNECTED 2

       int sockopt_callback(void *clientp,
			    curl_socket_t curlfd,
			    curlsocktype purpose);

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);

DESCRIPTION

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

       When set, this callback function gets called by libcurl when the socket has been created, but before the connect call to allow applications
       to change specific socket options. The callback's purpose argument identifies the exact purpose for this particular socket:

       CURLSOCKTYPE_IPCXN for actively created connections or since 7.28.0  CURLSOCKTYPE_ACCEPT  for  FTP  when  the  connection  was  setup  with
       PORT/EPSV (in earlier versions these sockets weren't passed to this callback).

       Future  versions  of  libcurl  may  support more purposes. libcurl passes the newly created socket descriptor to the callback in the curlfd
       parameter so additional setsockopt() calls can be done at the user's discretion.

       The clientp pointer contains whatever user-defined value set using the CURLOPT_SOCKOPTDATA(3) function.

       Return CURL_SOCKOPT_OK from the callback on success. Return CURL_SOCKOPT_ERROR from the callback function to signal an unrecoverable  error
       to  the	library and it will close the socket and return CURLE_COULDNT_CONNECT.	Alternatively, the callback function can return CURL_SOCK-
       OPT_ALREADY_CONNECTED, to tell libcurl that the socket is already connected and then libcurl will not attempt to connect it. This allows an
       application  to pass in an already connected socket with CURLOPT_OPENSOCKETFUNCTION(3) and then have this function make libcurl not attempt
       to connect (again).

DEFAULT

       By default, this callback is NULL and unused.

PROTOCOLS

       All

EXAMPLE

       TODO

AVAILABILITY

       Added in 7.16.0. The CURL_SOCKOPT_ALREADY_CONNECTED return code was added in 7.21.5.

RETURN VALUE

       Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO

       CURLOPT_SOCKOPTDATA(3), CURLOPT_OPENSOCKETFUNCTION(3),

libcurl 7.54.0							 February 03, 2016					CURLOPT_SOCKOPTFUNCTION(3)

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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)

Linux and UNIX Man Pages

curlopt_sockoptfunction(3) [mojave man page]

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