**************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
**************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
**************************************************************************
curl_easy_recv 3 "December 18, 2016" "libcurl 7.64.1" "libcurl Manual"
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.
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 facilities 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.
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) "