curl_easy_recv(3)

curl_easy_recv(3)        libcurl Manual         curl_easy_recv(3)

NAME

     curl_easy_recv - receives raw data on an "easy" connection

SYNOPSIS

     #include <curl/easy.h>

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

DESCRIPTION

     This function receives raw data from the established connec-
     tion.  You  may  use  it  together with curl_easy_send(3) to
     implement custom protocols using libcurl. This functionality
     can  be  particularly  useful  if you use proxies and/or SSL
     encryption: libcurl will take care of proxy negotiation  and
     connection set-up.

     buffer is a  pointer  to  your  buffer  that  will  get  the
     received  data. buflen is the maximum amount of data you can
     get in that buffer. The variable n points  to  will  receive
     the number of received 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_recv(3) does  not
     work on connections that were created without this option.

     The call will return CURLE_AGAIN if there is no data to read
     -  the  socket is used in non-blocking mode internally. When
     CURLE_AGAIN is returned, use your operating  system  facili-
     ties  like  select(2)  to  wait  for data. The socket may be
     obtained       using        curl_easy_getinfo(3)        with
     CURLINFO_ACTIVESOCKET(3).

     Wait  on  the  socket  only  if  curl_easy_recv(3)   returns
     CURLE_AGAIN.   The  reason  for  this  is libcurl or the SSL
     library may internally cache some data, therefore you should
     call  curl_easy_recv(3)  until  all data is read which would
     include any cached data.

     Furthermore if you wait on the socket and it tells you there
     is data to read, curl_easy_recv(3) may return CURLE_AGAIN if
     the only data that was read was for internal SSL processing,
     and no other data is available.

AVAILABILITY

     Added in 7.18.2.

RETURN VALUE

     On success, returns CURLE_OK, stores the received data  into
     buffer, and the number of bytes it actually read into *n.

libcurl 7.58.0   Last change: December 18, 2016                 1

curl_easy_recv(3)        libcurl Manual         curl_easy_recv(3)

     On failure, returns the appropriate error code.

     The function may return CURLE_AGAIN. In this case, use  your
     operating  system facilities to wait until data can be read,
     and retry.

     Reading exactly 0 bytes indicates a closed connection.

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

EXAMPLE

     See sendrecv.c in docs/examples directory for usage example.

SEE ALSO

     curl_easy_setopt(3),                   curl_easy_perform(3),
     curl_easy_getinfo(3), curl_easy_send(3)

libcurl 7.58.0   Last change: December 18, 2016                 2