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). 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_LASTSOCKET 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)