xenial (3) curl_easy_recv.3.gz

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  connection.  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.

       You  must  ensure  that  the socket has data to read before calling curl_easy_recv(3), otherwise the call
       will return CURLE_AGAIN - the socket is used in non-blocking mode  internally.  Use  curl_easy_getinfo(3)
       with  CURLINFO_ACTIVESOCKET(3)  to obtain the socket; use your operating system facilities like select(2)
       to check if it has any data you can read.

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.

       On failure, returns the appropriate error code.

       If  there  is  no data to read, the function returns CURLE_AGAIN. Use your operating system facilities to
       wait until the data is ready, and retry.

       Reading exactly 0 bytes would indicate 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)