# curl_easy_recv

Definition: | include builtins\libcurl.e {CURLcode res, integer len} = curl_easy_recv(atom curl, atom buffer, integer buflen)
Description: | Receives raw data on an "easy" connection. This function receives raw data from the established connection. You may use it together with curl_easy_send 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. Return value: On success, returns CURLE_OK, the data buffer, and the number of bytes it actually read. 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, and retry. The socket may be obtained using curl_easy_getinfo with CURLINFO_ACTIVESOCKET. On failure, returns the appropriate error code as the first element of the result. Reading exactly 0 bytes indicates a closed connection. If there is no socket available to use from the previous transfer, this function returns CURLE_UNSUPPORTED_PROTOCOL.
pwa/p2js: | Not supported.
Comments: | To establish the connection, set CURLOPT_CONNECT_ONLY option before calling curl_easy_perform or curl_multi_perform. Note that curl_easy_recv does not work on connections that were created without this option. Wait on the socket only if curl_easy_recv() 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 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 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.
See Also: | curl_easy_setopt, curl_easy_perform, curl_easy_getinfo, curl_easy_send