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afff64dbcd
Follow-up to 82245ea: Fix the example program sendrecv.c (handle
CURLE_AGAIN, handle incomplete send). Improve the documentation
for curl_easy_recv() and curl_easy_send().
Reviewed-by: Frank Meier
Assisted-by: Jay Satiro
See https://github.com/curl/curl/pull/1134
76 lines
3.4 KiB
Groff
76 lines
3.4 KiB
Groff
.\" **************************************************************************
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.\" * _ _ ____ _
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.\" * Project ___| | | | _ \| |
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.\" * / __| | | | |_) | |
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.\" * | (__| |_| | _ <| |___
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.\" * \___|\___/|_| \_\_____|
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.\" *
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.\" * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
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.\" *
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.\" * This software is licensed as described in the file COPYING, which
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.\" * you should have received as part of this distribution. The terms
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.\" * are also available at https://curl.haxx.se/docs/copyright.html.
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.\" *
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.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
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.\" * copies of the Software, and permit persons to whom the Software is
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.\" * furnished to do so, under the terms of the COPYING file.
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.\" *
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.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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.\" * KIND, either express or implied.
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.\" *
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.\" **************************************************************************
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.\"
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.TH curl_easy_send 3 "29 April 2008" "libcurl 7.18.2" "libcurl Manual"
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.SH NAME
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curl_easy_send - sends raw data over an "easy" connection
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.SH SYNOPSIS
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.B #include <curl/easy.h>
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.sp
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.BI "CURLcode curl_easy_send( CURL *" curl ", const void *" buffer ","
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.BI " size_t " buflen ", size_t *" n ");"
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.ad
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.SH DESCRIPTION
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This function sends arbitrary data over the established connection. You may
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use it together with \fIcurl_easy_recv(3)\fP to implement custom protocols
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using libcurl. This functionality can be particularly useful if you use
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proxies and/or SSL encryption: libcurl will take care of proxy negotiation and
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connection set-up.
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\fBbuffer\fP is a pointer to the data of length \fBbuflen\fP that you want sent.
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The variable \fBn\fP points to will receive the number of sent bytes.
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To establish the connection, set \fICURLOPT_CONNECT_ONLY(3)\fP option before
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calling \fIcurl_easy_perform(3)\fP or \fIcurl_multi_perform(3)\fP. Note that
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\fIcurl_easy_send(3)\fP will not work on connections that were created without
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this option.
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The call will return \fBCURLE_AGAIN\fP if it's not possible to send data right
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now - the socket is used in non-blocking mode internally. When
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\fBCURLE_AGAIN\fP is returned, use your operating system facilities like
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\fIselect(2)\fP to wait until the socket is writable. The socket may be
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obtained using \fIcurl_easy_getinfo(3)\fP with \fICURLINFO_ACTIVESOCKET(3)\fP.
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Furthermore if you wait on the socket and it tells you it's writable,
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\fIcurl_easy_send(3)\fP may return \fBCURLE_AGAIN\fP if the only data that was
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sent was for internal SSL processing, and no other data could be sent.
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.SH AVAILABILITY
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Added in 7.18.2.
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.SH RETURN VALUE
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On success, returns \fBCURLE_OK\fP and stores the number of bytes actually
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sent into \fB*n\fP. Note that this may very well be less than the amount you
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wanted to send.
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On failure, returns the appropriate error code.
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This function may return \fBCURLE_AGAIN\fP. In this case, use your operating
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system facilities to wait until the socket is writable, and retry.
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If there's no socket available to use from the previous transfer, this function
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returns \fBCURLE_UNSUPPORTED_PROTOCOL\fP.
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.SH EXAMPLE
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See \fBsendrecv.c\fP in \fBdocs/examples\fP directory for usage example.
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.SH "SEE ALSO"
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.BR curl_easy_setopt "(3), " curl_easy_perform "(3), " curl_easy_getinfo "(3), "
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.BR curl_easy_recv "(3) "
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