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Updated: Thursday, June 13, 2019
 
 

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

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 proto-
       type 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 callback
       was called.  If the given callback pointer is NULL, no callback will be
       called.  Set the callback's userp argument with CURLMOPT_SOCKETDATA(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
       static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
       {
         GlobalInfo *g = (GlobalInfo*) cbp;
         SockInfo *fdp = (SockInfo*) sockp;

         if(what == CURL_POLL_REMOVE) {
           remsock(fdp);
         }
         else {
           if(!fdp) {
             addsock(s, e, what, g);
           }
           else {
             setsock(fdp, s, e, what, g);
           }
         }
         return 0;
       }

       main()
       {
         GlobalInfo setup;
         /* ... use socket callback and custom pointer */
         curl_multi_setopt(multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
         curl_multi_setopt(multi, CURLMOPT_SOCKETDATA, &setup);
       }

AVAILABILITY
       Added in 7.15.4

RETURN VALUE
       Returns CURLM_OK.


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+------------------+
       |ATTRIBUTE TYPE | ATTRIBUTE VALUE  |
       +---------------+------------------+
       |Availability   | web/curl         |
       +---------------+------------------+
       |Stability      | Uncommitted      |
       +---------------+------------------+
SEE ALSO
       CURLMOPT_SOCKETDATA(3),  curl_multi_socket_action(3),   CURLMOPT_TIMER-
       FUNCTION(3)



NOTES
       This     software     was    built    from    source    available    at
       https://github.com/oracle/solaris-userland.   The  original   community
       source    was    downloaded    from    https://github.com/curl/curl/ar-
       chive/curl-7_64_0.zip

       Further information about this software can be found on the open source
       community website at http://curl.haxx.se/.



libcurl 7.39.0                    3 Nov 2016
                                                    CURLMOPT_SOCKETFUNCTION(3)