Imported Upstream version 7.59.0

[platform/upstream/curl.git] / docs / libcurl / curl_easy_recv.3

diff --git a/docs/libcurl/curl_easy_recv.3 b/docs/libcurl/curl_easy_recv.3
index d425fe2..8a002ea 100644 (file)
--- a/docs/libcurl/curl_easy_recv.3
+++ b/docs/libcurl/curl_easy_recv.3
@@ -5,11 +5,11 @@
 .\" *                            | (__| |_| |  _ <| |___
 .\" *                             \___|\___/|_| \_\_____|
 .\" *
-.\" * Copyright (C) 1998 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
+.\" * 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 http://curl.haxx.se/docs/copyright.html.
+.\" * 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
@@ -20,7 +20,8 @@
 .\" *
 .\" **************************************************************************
 .\"
-.TH curl_easy_recv 3 "29 April 2008" "libcurl 7.18.2" "libcurl Manual"
+.TH curl_easy_recv 3 "December 18, 2016" "libcurl 7.59.0" "libcurl Manual"
+
 .SH NAME
 curl_easy_recv - receives raw data on an "easy" connection
 .SH SYNOPSIS
@@ -41,17 +42,26 @@ data. \fBbuflen\fP is the maximum amount of data you can get in that
 buffer. The variable \fBn\fP points to will receive the number of received
 bytes.
 
-To establish the connection, set \fBCURLOPT_CONNECT_ONLY(3)\fP option before
+To establish the connection, set \fICURLOPT_CONNECT_ONLY(3)\fP option before
 calling \fIcurl_easy_perform(3)\fP or \fIcurl_multi_perform(3)\fP. Note that
 \fIcurl_easy_recv(3)\fP does not work on connections that were created without
 this option.
 
-You must ensure that the socket has data to read before calling
-\fIcurl_easy_recv(3)\fP, otherwise the call will return \fBCURLE_AGAIN\fP -
-the socket is used in non-blocking mode internally. Use
-\fIcurl_easy_getinfo(3)\fP with \fBCURLINFO_LASTSOCKET\fP to obtain the
-socket; use your operating system facilities like \fIselect(2)\fP to check if
-it has any data you can read.
+The call will return \fBCURLE_AGAIN\fP if there is no data to read - the
+socket is used in non-blocking mode internally. When \fBCURLE_AGAIN\fP is
+returned, use your operating system facilities like \fIselect(2)\fP to wait
+for data. The socket may be obtained using \fIcurl_easy_getinfo(3)\fP with
+\fICURLINFO_ACTIVESOCKET(3)\fP.
+
+Wait on the socket only if \fIcurl_easy_recv(3)\fP returns \fBCURLE_AGAIN\fP.
+The reason for this is libcurl or the SSL library may internally cache some
+data, therefore you should call \fIcurl_easy_recv(3)\fP 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,
+\fIcurl_easy_recv(3)\fP may return \fBCURLE_AGAIN\fP if the only data that was
+read was for internal SSL processing, and no other data is available.
+
 .SH AVAILABILITY
 Added in 7.18.2.
 .SH RETURN VALUE
@@ -60,13 +70,13 @@ On success, returns \fBCURLE_OK\fP, stores the received data into
 
 On failure, returns the appropriate error code.
 
-If there is no data to read, the function returns \fBCURLE_AGAIN\fP. Use your
-operating system facilities to wait until the data is ready, and retry.
+The function may return \fBCURLE_AGAIN\fP. In this case, use your operating
+system facilities to wait until data can be read, and retry.
 
-Reading exactly 0 bytes would indicate a closed connection.
+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.
+returns \fBCURLE_UNSUPPORTED_PROTOCOL\fP.
 .SH EXAMPLE
 See \fBsendrecv.c\fP in \fBdocs/examples\fP directory for usage example.
 .SH "SEE ALSO"