1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>websocket::stream::handshake (2 of 4 overloads)</title> 5<link rel="stylesheet" href="../../../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../../index.html" title="Chapter 1. Boost.Beast"> 8<link rel="up" href="../handshake.html" title="websocket::stream::handshake"> 9<link rel="prev" href="overload1.html" title="websocket::stream::handshake (1 of 4 overloads)"> 10<link rel="next" href="overload3.html" title="websocket::stream::handshake (3 of 4 overloads)"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="overload1.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../handshake.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="overload3.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h6 class="title"> 27<a name="beast.ref.boost__beast__websocket__stream.handshake.overload2"></a><a class="link" href="overload2.html" title="websocket::stream::handshake (2 of 4 overloads)">websocket::stream::handshake 28 (2 of 4 overloads)</a> 29</h6></div></div></div> 30<p> 31 Perform the WebSocket handshake in the client role. 32 </p> 33<h7><a name="beast.ref.boost__beast__websocket__stream.handshake.overload2.h0"></a> 34 <span class="phrase"><a name="beast.ref.boost__beast__websocket__stream.handshake.overload2.synopsis"></a></span><a class="link" href="overload2.html#beast.ref.boost__beast__websocket__stream.handshake.overload2.synopsis">Synopsis</a> 35 </h7><pre class="programlisting"><span class="keyword">void</span> 36<span class="identifier">handshake</span><span class="special">(</span> 37 <span class="identifier">response_type</span><span class="special">&</span> <span class="identifier">res</span><span class="special">,</span> 38 <span class="identifier">string_view</span> <span class="identifier">host</span><span class="special">,</span> 39 <span class="identifier">string_view</span> <span class="identifier">target</span><span class="special">);</span> 40</pre> 41<h7><a name="beast.ref.boost__beast__websocket__stream.handshake.overload2.h1"></a> 42 <span class="phrase"><a name="beast.ref.boost__beast__websocket__stream.handshake.overload2.description"></a></span><a class="link" href="overload2.html#beast.ref.boost__beast__websocket__stream.handshake.overload2.description">Description</a> 43 </h7><p> 44 This function is used to perform the <a href="https://en.wikipedia.org/wiki/WebSocket#Protocol_handshake" target="_top">WebSocket 45 handshake</a>, required before messages can be sent and received. 46 During the handshake, the client sends the Websocket Upgrade HTTP request, 47 and the server replies with an HTTP response indicating the result of 48 the handshake. The call blocks until one of the following conditions 49 is true: 50 </p> 51<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 52<li class="listitem"> 53 The request is sent and the response is received. 54 </li> 55<li class="listitem"> 56 An error occurs. 57 </li> 58</ul></div> 59<p> 60 The algorithm, known as a <span class="emphasis"><em>composed operation</em></span>, is 61 implemented in terms of calls to the next layer's <code class="computeroutput"><span class="identifier">read_some</span></code> 62 and <code class="computeroutput"><span class="identifier">write_some</span></code> functions. 63 The handshake is successful if the received HTTP response indicates the 64 upgrade was accepted by the server, represented by a <a href="https://tools.ietf.org/html/rfc7230#section-3.1.2" target="_top">status-code</a> 65 of <a class="link" href="../../boost__beast__http__status.html" title="http::status"><code class="computeroutput"><span class="identifier">beast</span><span class="special">::</span><span class="identifier">http</span><span class="special">::</span><span class="identifier">status</span><span class="special">::</span><span class="identifier">switching_protocols</span></code></a>. 66 </p> 67<h7><a name="beast.ref.boost__beast__websocket__stream.handshake.overload2.h2"></a> 68 <span class="phrase"><a name="beast.ref.boost__beast__websocket__stream.handshake.overload2.parameters"></a></span><a class="link" href="overload2.html#beast.ref.boost__beast__websocket__stream.handshake.overload2.parameters">Parameters</a> 69 </h7><div class="informaltable"><table class="table"> 70<colgroup> 71<col> 72<col> 73</colgroup> 74<thead><tr> 75<th> 76 <p> 77 Name 78 </p> 79 </th> 80<th> 81 <p> 82 Description 83 </p> 84 </th> 85</tr></thead> 86<tbody> 87<tr> 88<td> 89 <p> 90 <code class="computeroutput"><span class="identifier">res</span></code> 91 </p> 92 </td> 93<td> 94 <p> 95 The HTTP Upgrade response returned by the remote endpoint. 96 The caller may use the response to access any additional information 97 sent by the server. 98 </p> 99 </td> 100</tr> 101<tr> 102<td> 103 <p> 104 <code class="computeroutput"><span class="identifier">host</span></code> 105 </p> 106 </td> 107<td> 108 <p> 109 The name of the remote host. This is required by the HTTP protocol 110 to set the "Host" header field. 111 </p> 112 </td> 113</tr> 114<tr> 115<td> 116 <p> 117 <code class="computeroutput"><span class="identifier">target</span></code> 118 </p> 119 </td> 120<td> 121 <p> 122 The request-target, in origin-form. The server may use the 123 target to distinguish different services on the same listening 124 port. 125 </p> 126 </td> 127</tr> 128</tbody> 129</table></div> 130<h7><a name="beast.ref.boost__beast__websocket__stream.handshake.overload2.h3"></a> 131 <span class="phrase"><a name="beast.ref.boost__beast__websocket__stream.handshake.overload2.exceptions"></a></span><a class="link" href="overload2.html#beast.ref.boost__beast__websocket__stream.handshake.overload2.exceptions">Exceptions</a> 132 </h7><div class="informaltable"><table class="table"> 133<colgroup> 134<col> 135<col> 136</colgroup> 137<thead><tr> 138<th> 139 <p> 140 Type 141 </p> 142 </th> 143<th> 144 <p> 145 Thrown On 146 </p> 147 </th> 148</tr></thead> 149<tbody><tr> 150<td> 151 <p> 152 <code class="computeroutput"><span class="identifier">system_error</span></code> 153 </p> 154 </td> 155<td> 156 <p> 157 Thrown on failure. 158 </p> 159 </td> 160</tr></tbody> 161</table></div> 162<h7><a name="beast.ref.boost__beast__websocket__stream.handshake.overload2.h4"></a> 163 <span class="phrase"><a name="beast.ref.boost__beast__websocket__stream.handshake.overload2.example"></a></span><a class="link" href="overload2.html#beast.ref.boost__beast__websocket__stream.handshake.overload2.example">Example</a> 164 </h7><pre class="programlisting"><span class="identifier">response_type</span> <span class="identifier">res</span><span class="special">;</span> 165<span class="identifier">ws</span><span class="special">.</span><span class="identifier">handshake</span><span class="special">(</span><span class="identifier">res</span><span class="special">,</span> <span class="string">"localhost"</span><span class="special">,</span> <span class="string">"/"</span><span class="special">);</span> 166<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">res</span><span class="special">;</span> 167</pre> 168<h7><a name="beast.ref.boost__beast__websocket__stream.handshake.overload2.h5"></a> 169 <span class="phrase"><a name="beast.ref.boost__beast__websocket__stream.handshake.overload2.see_also"></a></span><a class="link" href="overload2.html#beast.ref.boost__beast__websocket__stream.handshake.overload2.see_also">See 170 Also</a> 171 </h7><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 172<li class="listitem"> 173 <a href="https://tools.ietf.org/html/rfc6455#section-4.1" target="_top">Websocket 174 Opening Handshake Client Requirements (RFC6455)</a> 175 </li> 176<li class="listitem"> 177 <a href="https://tools.ietf.org/html/rfc7230#section-5.4" target="_top">Host 178 field (RFC7230)</a> 179 </li> 180<li class="listitem"> 181 <a href="https://tools.ietf.org/html/rfc7230#section-3.1.1" target="_top">request-target 182 (RFC7230)</a> 183 </li> 184<li class="listitem"> 185 <a href="https://tools.ietf.org/html/rfc7230#section-5.3.1" target="_top">origin-form 186 (RFC7230)</a> 187 </li> 188</ul></div> 189</div> 190<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 191<td align="left"></td> 192<td align="right"><div class="copyright-footer">Copyright © 2016-2019 Vinnie 193 Falco<p> 194 Distributed under the Boost Software License, Version 1.0. (See accompanying 195 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 196 </p> 197</div></td> 198</tr></table> 199<hr> 200<div class="spirit-nav"> 201<a accesskey="p" href="overload1.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../handshake.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="overload3.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 202</div> 203</body> 204</html> 205
