ded/cpp-httplib
1
0
Fork 0
mirror of https://github.com/yhirose/cpp-httplib.git synced 2026-04-12 19:58:29 +00:00
Code Issues Packages Projects Releases Wiki Activity
Files
bb2255308724cebfb4fa5eb55a9b3f5f9d817179
cpp-httplib/docs/en/tour/08-websocket/index.html

329 lines
28 KiB
HTML
Raw Blame History

<!DOCTYPE html>
<html lang="en" data-base-path="&#x2F;cpp-httplib">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>WebSocket - cpp-httplib</title>
<link rel="icon" type="image/svg+xml" href="&#x2F;cpp-httplib/favicon.svg">
<link rel="stylesheet" href="&#x2F;cpp-httplib/css/main.css">
<script>
(function() {
var t = localStorage.getItem('preferred-theme');
if (!t) t = window.matchMedia('(prefers-color-scheme: light)').matches ? 'light' : 'dark';
if (t === 'light') document.documentElement.setAttribute('data-theme', 'light');
})();
</script>
</head>
<body>
<header class="header">
<div class="header-inner">
<a href="&#x2F;cpp-httplib/en/" class="header-title">cpp-httplib <span style="font-size:0.75em;font-weight:normal;margin-left:4px">v0.35.0</span></a>
<div class="header-spacer"></div>
<nav class="header-nav">
<a href="&#x2F;cpp-httplib/en/">
<svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M3 9l9-7 9 7v11a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2z"/><polyline points="9 22 9 12 15 12 15 22"/></svg>
Home
</a>
<a href="&#x2F;cpp-httplib/en/tour&#x2F;">
<svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="10"/><polygon points="16.24 7.76 14.12 14.12 7.76 16.24 9.88 9.88 16.24 7.76"/></svg>
Tour
</a>
<a href="https:&#x2F;&#x2F;github.com&#x2F;yhirose&#x2F;cpp-httplib" aria-label="GitHub">
<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M9 19c-5 1.5-5-2.5-7-3m14 6v-3.87a3.37 3.37 0 0 0-.94-2.61c3.14-.35 6.44-1.54 6.44-7A5.44 5.44 0 0 0 20 4.77 5.07 5.07 0 0 0 19.91 1S18.73.65 16 2.48a13.38 13.38 0 0 0-7 0C6.27.65 5.09 1 5.09 1A5.07 5.07 0 0 0 5 4.77a5.44 5.44 0 0 0-1.5 3.78c0 5.42 3.3 6.61 6.44 7A3.37 3.37 0 0 0 9 18.13V22"/></svg>
GitHub
</a>
</nav>
<div class="header-tools">
<button class="search-btn" aria-label="Search (⌘K)">
<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="11" cy="11" r="8"/><line x1="21" y1="21" x2="16.65" y2="16.65"/></svg>
</button>
<button class="theme-toggle" aria-label="Toggle theme"></button>
<div class="lang-selector">
<button class="lang-btn" aria-label="Language">
<svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="10"/><line x1="2" y1="12" x2="22" y2="12"/><path d="M12 2a15.3 15.3 0 0 1 4 10 15.3 15.3 0 0 1-4 10 15.3 15.3 0 0 1-4-10 15.3 15.3 0 0 1 4-10z"/></svg>
EN
</button>
<ul class="lang-popup">
<li><a href="#" data-lang="en">EN</a></li>
<li><a href="#" data-lang="ja">JA</a></li>
</ul>
</div>
</div>
<button class="sidebar-toggle" aria-label="Menu">&#9776;</button>
</div>
</header>
<div class="layout has-sidebar">
<aside class="sidebar">
<nav class="sidebar-nav">
<div class="nav-section">
<a href="&#x2F;cpp-httplib&#x2F;en&#x2F;tour&#x2F;" class="nav-section-title active">A Tour of cpp-httplib</a>
<ul class="nav-list">
<li><a href="&#x2F;cpp-httplib&#x2F;en&#x2F;tour&#x2F;01-getting-started&#x2F;" class="">Getting Started</a></li>
<li><a href="&#x2F;cpp-httplib&#x2F;en&#x2F;tour&#x2F;02-basic-client&#x2F;" class="">Basic Client</a></li>
<li><a href="&#x2F;cpp-httplib&#x2F;en&#x2F;tour&#x2F;03-basic-server&#x2F;" class="">Basic Server</a></li>
<li><a href="&#x2F;cpp-httplib&#x2F;en&#x2F;tour&#x2F;04-static-file-server&#x2F;" class="">Static File Server</a></li>
<li><a href="&#x2F;cpp-httplib&#x2F;en&#x2F;tour&#x2F;05-tls-setup&#x2F;" class="">TLS Setup</a></li>
<li><a href="&#x2F;cpp-httplib&#x2F;en&#x2F;tour&#x2F;06-https-client&#x2F;" class="">HTTPS Client</a></li>
<li><a href="&#x2F;cpp-httplib&#x2F;en&#x2F;tour&#x2F;07-https-server&#x2F;" class="">HTTPS Server</a></li>
<li><a href="&#x2F;cpp-httplib&#x2F;en&#x2F;tour&#x2F;08-websocket&#x2F;" class="active">WebSocket</a></li>
<li><a href="&#x2F;cpp-httplib&#x2F;en&#x2F;tour&#x2F;09-whats-next&#x2F;" class="">What&#x27;s Next</a></li>
</ul>
</div>
</nav>
</aside>
<main class="content">
<article>
<h1>WebSocket</h1>
<p>cpp-httplib supports WebSocket as well. Unlike HTTP request/response, WebSocket lets the server and client exchange messages in both directions. It's great for chat apps and real-time notifications.</p>
<p>Let's build an echo server and client right away.</p>
<h2>Echo Server</h2>
<p>Here's an echo server that sends back whatever message it receives.</p>
<div class="code-block-wrapper"><div data-code-theme="dark"><pre style="background-color:#2d2d2d;">
<span style="color:#cc99cc;">#include </span><span style="color:#d3d0c8;">&quot;</span><span style="color:#99cc99;">httplib.h</span><span style="color:#d3d0c8;">&quot;
</span><span style="color:#cc99cc;">#include </span><span style="color:#d3d0c8;">&lt;</span><span style="color:#99cc99;">iostream</span><span style="color:#d3d0c8;">&gt;
</span><span style="color:#d3d0c8;">
</span><span style="color:#cc99cc;">int </span><span style="color:#6699cc;">main</span><span style="color:#d3d0c8;">() {
</span><span style="color:#d3d0c8;"> httplib::Server svr;
</span><span style="color:#d3d0c8;">
</span><span style="color:#d3d0c8;"> svr.</span><span style="color:#6699cc;">WebSocket</span><span style="color:#d3d0c8;">(&quot;</span><span style="color:#99cc99;">/ws</span><span style="color:#d3d0c8;">&quot;, [](</span><span style="color:#cc99cc;">const</span><span style="color:#d3d0c8;"> httplib::Request &amp;, httplib::ws::WebSocket &amp;ws) {
</span><span style="color:#d3d0c8;"> std::string msg;
</span><span style="color:#d3d0c8;"> </span><span style="color:#cc99cc;">while </span><span style="color:#d3d0c8;">(ws.</span><span style="color:#6699cc;">read</span><span style="color:#d3d0c8;">(msg)) {
</span><span style="color:#d3d0c8;"> ws.</span><span style="color:#6699cc;">send</span><span style="color:#d3d0c8;">(msg); </span><span style="color:#747369;">// Send back the received message as-is
</span><span style="color:#d3d0c8;"> }
</span><span style="color:#d3d0c8;"> });
</span><span style="color:#d3d0c8;">
</span><span style="color:#d3d0c8;"> std::cout &lt;&lt; &quot;</span><span style="color:#99cc99;">Listening on port 8080...</span><span style="color:#d3d0c8;">&quot; &lt;&lt; std::endl;
</span><span style="color:#d3d0c8;"> svr.</span><span style="color:#6699cc;">listen</span><span style="color:#d3d0c8;">(&quot;</span><span style="color:#99cc99;">0.0.0.0</span><span style="color:#d3d0c8;">&quot;, </span><span style="color:#f99157;">8080</span><span style="color:#d3d0c8;">);
</span><span style="color:#d3d0c8;">}
</span></pre>
</div><div data-code-theme="light"><pre style="background-color:#ffffff;">
<span style="font-weight:bold;color:#a71d5d;">#include </span><span style="color:#183691;">&quot;httplib.h&quot;
</span><span style="font-weight:bold;color:#a71d5d;">#include </span><span style="color:#183691;">&lt;iostream&gt;
</span><span style="color:#323232;">
</span><span style="font-weight:bold;color:#a71d5d;">int </span><span style="font-weight:bold;color:#795da3;">main</span><span style="color:#323232;">() {
</span><span style="color:#323232;"> httplib::Server svr;
</span><span style="color:#323232;">
</span><span style="color:#323232;"> svr.WebSocket(</span><span style="color:#183691;">&quot;/ws&quot;</span><span style="color:#323232;">, [](</span><span style="font-weight:bold;color:#a71d5d;">const</span><span style="color:#323232;"> httplib::Request </span><span style="font-weight:bold;color:#a71d5d;">&amp;</span><span style="color:#323232;">, httplib::ws::WebSocket </span><span style="font-weight:bold;color:#a71d5d;">&amp;</span><span style="color:#323232;">ws) {
</span><span style="color:#323232;"> std::string msg;
</span><span style="color:#323232;"> </span><span style="font-weight:bold;color:#a71d5d;">while </span><span style="color:#323232;">(ws.read(msg)) {
</span><span style="color:#323232;"> ws.send(msg); </span><span style="font-style:italic;color:#969896;">// Send back the received message as-is
</span><span style="color:#323232;"> }
</span><span style="color:#323232;"> });
</span><span style="color:#323232;">
</span><span style="color:#323232;"> std::cout </span><span style="font-weight:bold;color:#a71d5d;">&lt;&lt; </span><span style="color:#183691;">&quot;Listening on port 8080...&quot; </span><span style="font-weight:bold;color:#a71d5d;">&lt;&lt;</span><span style="color:#323232;"> std::endl;
</span><span style="color:#323232;"> svr.listen(</span><span style="color:#183691;">&quot;0.0.0.0&quot;</span><span style="color:#323232;">, </span><span style="color:#0086b3;">8080</span><span style="color:#323232;">);
</span><span style="color:#323232;">}
</span></pre>
</div></div>
<p>You register a WebSocket handler with <code>svr.WebSocket()</code>. It works just like <code>svr.Get()</code> and <code>svr.Post()</code> from Chapter 3.</p>
<p>Inside the handler, <code>ws.read(msg)</code> waits for a message. When the connection closes, <code>read()</code> returns <code>false</code>, so the loop exits. <code>ws.send(msg)</code> sends a message back.</p>
<h2>Connecting from a Client</h2>
<p>Let's connect to the server using <code>httplib::ws::WebSocketClient</code>.</p>
<div class="code-block-wrapper"><div data-code-theme="dark"><pre style="background-color:#2d2d2d;">
<span style="color:#cc99cc;">#include </span><span style="color:#d3d0c8;">&quot;</span><span style="color:#99cc99;">httplib.h</span><span style="color:#d3d0c8;">&quot;
</span><span style="color:#cc99cc;">#include </span><span style="color:#d3d0c8;">&lt;</span><span style="color:#99cc99;">iostream</span><span style="color:#d3d0c8;">&gt;
</span><span style="color:#d3d0c8;">
</span><span style="color:#cc99cc;">int </span><span style="color:#6699cc;">main</span><span style="color:#d3d0c8;">() {
</span><span style="color:#d3d0c8;"> httplib::ws::WebSocketClient </span><span style="color:#6699cc;">client</span><span style="color:#d3d0c8;">(&quot;</span><span style="color:#99cc99;">ws://localhost:8080/ws</span><span style="color:#d3d0c8;">&quot;);
</span><span style="color:#d3d0c8;">
</span><span style="color:#d3d0c8;"> </span><span style="color:#cc99cc;">if </span><span style="color:#d3d0c8;">(!client.</span><span style="color:#6699cc;">connect</span><span style="color:#d3d0c8;">()) {
</span><span style="color:#d3d0c8;"> std::cout &lt;&lt; &quot;</span><span style="color:#99cc99;">Connection failed</span><span style="color:#d3d0c8;">&quot; &lt;&lt; std::endl;
</span><span style="color:#d3d0c8;"> </span><span style="color:#cc99cc;">return </span><span style="color:#f99157;">1</span><span style="color:#d3d0c8;">;
</span><span style="color:#d3d0c8;"> }
</span><span style="color:#d3d0c8;">
</span><span style="color:#d3d0c8;"> </span><span style="color:#747369;">// Send a message
</span><span style="color:#d3d0c8;"> client.</span><span style="color:#6699cc;">send</span><span style="color:#d3d0c8;">(&quot;</span><span style="color:#99cc99;">Hello, WebSocket!</span><span style="color:#d3d0c8;">&quot;);
</span><span style="color:#d3d0c8;">
</span><span style="color:#d3d0c8;"> </span><span style="color:#747369;">// Receive a response from the server
</span><span style="color:#d3d0c8;"> std::string msg;
</span><span style="color:#d3d0c8;"> </span><span style="color:#cc99cc;">if </span><span style="color:#d3d0c8;">(client.</span><span style="color:#6699cc;">read</span><span style="color:#d3d0c8;">(msg)) {
</span><span style="color:#d3d0c8;"> std::cout &lt;&lt; msg &lt;&lt; std::endl; </span><span style="color:#747369;">// Hello, WebSocket!
</span><span style="color:#d3d0c8;"> }
</span><span style="color:#d3d0c8;">
</span><span style="color:#d3d0c8;"> client.</span><span style="color:#6699cc;">close</span><span style="color:#d3d0c8;">();
</span><span style="color:#d3d0c8;">}
</span></pre>
</div><div data-code-theme="light"><pre style="background-color:#ffffff;">
<span style="font-weight:bold;color:#a71d5d;">#include </span><span style="color:#183691;">&quot;httplib.h&quot;
</span><span style="font-weight:bold;color:#a71d5d;">#include </span><span style="color:#183691;">&lt;iostream&gt;
</span><span style="color:#323232;">
</span><span style="font-weight:bold;color:#a71d5d;">int </span><span style="font-weight:bold;color:#795da3;">main</span><span style="color:#323232;">() {
</span><span style="color:#323232;"> httplib::ws::WebSocketClient client(</span><span style="color:#183691;">&quot;ws://localhost:8080/ws&quot;</span><span style="color:#323232;">);
</span><span style="color:#323232;">
</span><span style="color:#323232;"> </span><span style="font-weight:bold;color:#a71d5d;">if </span><span style="color:#323232;">(</span><span style="font-weight:bold;color:#a71d5d;">!</span><span style="color:#323232;">client.connect()) {
</span><span style="color:#323232;"> std::cout </span><span style="font-weight:bold;color:#a71d5d;">&lt;&lt; </span><span style="color:#183691;">&quot;Connection failed&quot; </span><span style="font-weight:bold;color:#a71d5d;">&lt;&lt;</span><span style="color:#323232;"> std::endl;
</span><span style="color:#323232;"> </span><span style="font-weight:bold;color:#a71d5d;">return </span><span style="color:#0086b3;">1</span><span style="color:#323232;">;
</span><span style="color:#323232;"> }
</span><span style="color:#323232;">
</span><span style="color:#323232;"> </span><span style="font-style:italic;color:#969896;">// Send a message
</span><span style="color:#323232;"> client.send(</span><span style="color:#183691;">&quot;Hello, WebSocket!&quot;</span><span style="color:#323232;">);
</span><span style="color:#323232;">
</span><span style="color:#323232;"> </span><span style="font-style:italic;color:#969896;">// Receive a response from the server
</span><span style="color:#323232;"> std::string msg;
</span><span style="color:#323232;"> </span><span style="font-weight:bold;color:#a71d5d;">if </span><span style="color:#323232;">(client.read(msg)) {
</span><span style="color:#323232;"> std::cout </span><span style="font-weight:bold;color:#a71d5d;">&lt;&lt;</span><span style="color:#323232;"> msg </span><span style="font-weight:bold;color:#a71d5d;">&lt;&lt;</span><span style="color:#323232;"> std::endl; </span><span style="font-style:italic;color:#969896;">// Hello, WebSocket!
</span><span style="color:#323232;"> }
</span><span style="color:#323232;">
</span><span style="color:#323232;"> client.close();
</span><span style="color:#323232;">}
</span></pre>
</div></div>
<p>Pass a URL in <code>ws://host:port/path</code> format to the constructor. Call <code>connect()</code> to start the connection, then use <code>send()</code> and <code>read()</code> to exchange messages.</p>
<h2>Text and Binary</h2>
<p>WebSocket has two types of messages: text and binary. You can tell them apart by the return value of <code>read()</code>.</p>
<div class="code-block-wrapper"><div data-code-theme="dark"><pre style="background-color:#2d2d2d;">
<span style="color:#d3d0c8;">svr.</span><span style="color:#6699cc;">WebSocket</span><span style="color:#d3d0c8;">(&quot;</span><span style="color:#99cc99;">/ws</span><span style="color:#d3d0c8;">&quot;, [](</span><span style="color:#cc99cc;">const</span><span style="color:#d3d0c8;"> httplib::Request &amp;, httplib::ws::WebSocket &amp;ws) {
</span><span style="color:#d3d0c8;"> std::string msg;
</span><span style="color:#d3d0c8;"> httplib::ws::ReadResult ret;
</span><span style="color:#d3d0c8;"> </span><span style="color:#cc99cc;">while </span><span style="color:#d3d0c8;">((ret = ws.</span><span style="color:#6699cc;">read</span><span style="color:#d3d0c8;">(msg))) {
</span><span style="color:#d3d0c8;"> </span><span style="color:#cc99cc;">if </span><span style="color:#d3d0c8;">(ret == httplib::ws::Binary) {
</span><span style="color:#d3d0c8;"> ws.</span><span style="color:#6699cc;">send</span><span style="color:#d3d0c8;">(msg.</span><span style="color:#6699cc;">data</span><span style="color:#d3d0c8;">(), msg.</span><span style="color:#6699cc;">size</span><span style="color:#d3d0c8;">()); </span><span style="color:#747369;">// Send as binary
</span><span style="color:#d3d0c8;"> } </span><span style="color:#cc99cc;">else </span><span style="color:#d3d0c8;">{
</span><span style="color:#d3d0c8;"> ws.</span><span style="color:#6699cc;">send</span><span style="color:#d3d0c8;">(msg); </span><span style="color:#747369;">// Send as text
</span><span style="color:#d3d0c8;"> }
</span><span style="color:#d3d0c8;"> }
</span><span style="color:#d3d0c8;">});
</span></pre>
</div><div data-code-theme="light"><pre style="background-color:#ffffff;">
<span style="color:#323232;">svr.WebSocket(</span><span style="color:#183691;">&quot;/ws&quot;</span><span style="color:#323232;">, [](</span><span style="font-weight:bold;color:#a71d5d;">const</span><span style="color:#323232;"> httplib::Request </span><span style="font-weight:bold;color:#a71d5d;">&amp;</span><span style="color:#323232;">, httplib::ws::WebSocket </span><span style="font-weight:bold;color:#a71d5d;">&amp;</span><span style="color:#323232;">ws) {
</span><span style="color:#323232;"> std::string msg;
</span><span style="color:#323232;"> httplib::ws::ReadResult ret;
</span><span style="color:#323232;"> </span><span style="font-weight:bold;color:#a71d5d;">while </span><span style="color:#323232;">((ret </span><span style="font-weight:bold;color:#a71d5d;">=</span><span style="color:#323232;"> ws.read(msg))) {
</span><span style="color:#323232;"> </span><span style="font-weight:bold;color:#a71d5d;">if </span><span style="color:#323232;">(ret </span><span style="font-weight:bold;color:#a71d5d;">==</span><span style="color:#323232;"> httplib::ws::Binary) {
</span><span style="color:#323232;"> ws.send(msg.data(), msg.size()); </span><span style="font-style:italic;color:#969896;">// Send as binary
</span><span style="color:#323232;"> } </span><span style="font-weight:bold;color:#a71d5d;">else </span><span style="color:#323232;">{
</span><span style="color:#323232;"> ws.send(msg); </span><span style="font-style:italic;color:#969896;">// Send as text
</span><span style="color:#323232;"> }
</span><span style="color:#323232;"> }
</span><span style="color:#323232;">});
</span></pre>
</div></div>
<ul>
<li><code>ws.send(const std::string &amp;)</code> — sends as a text message</li>
<li><code>ws.send(const char *, size_t)</code> — sends as a binary message</li>
</ul>
<p>The client-side API is the same.</p>
<h2>Accessing Request Information</h2>
<p>You can read HTTP request information from the handshake through the first argument <code>req</code> in the handler. This is handy for checking authentication tokens.</p>
<div class="code-block-wrapper"><div data-code-theme="dark"><pre style="background-color:#2d2d2d;">
<span style="color:#d3d0c8;">svr.</span><span style="color:#6699cc;">WebSocket</span><span style="color:#d3d0c8;">(&quot;</span><span style="color:#99cc99;">/ws</span><span style="color:#d3d0c8;">&quot;, [](</span><span style="color:#cc99cc;">const</span><span style="color:#d3d0c8;"> httplib::Request &amp;req, httplib::ws::WebSocket &amp;ws) {
</span><span style="color:#d3d0c8;"> </span><span style="color:#cc99cc;">auto</span><span style="color:#d3d0c8;"> token = req.</span><span style="color:#6699cc;">get_header_value</span><span style="color:#d3d0c8;">(&quot;</span><span style="color:#99cc99;">Authorization</span><span style="color:#d3d0c8;">&quot;);
</span><span style="color:#d3d0c8;"> </span><span style="color:#cc99cc;">if </span><span style="color:#d3d0c8;">(token.</span><span style="color:#6699cc;">empty</span><span style="color:#d3d0c8;">()) {
</span><span style="color:#d3d0c8;"> ws.</span><span style="color:#6699cc;">close</span><span style="color:#d3d0c8;">(httplib::ws::CloseStatus::PolicyViolation, &quot;</span><span style="color:#99cc99;">unauthorized</span><span style="color:#d3d0c8;">&quot;);
</span><span style="color:#d3d0c8;"> </span><span style="color:#cc99cc;">return</span><span style="color:#d3d0c8;">;
</span><span style="color:#d3d0c8;"> }
</span><span style="color:#d3d0c8;">
</span><span style="color:#d3d0c8;"> std::string msg;
</span><span style="color:#d3d0c8;"> </span><span style="color:#cc99cc;">while </span><span style="color:#d3d0c8;">(ws.</span><span style="color:#6699cc;">read</span><span style="color:#d3d0c8;">(msg)) {
</span><span style="color:#d3d0c8;"> ws.</span><span style="color:#6699cc;">send</span><span style="color:#d3d0c8;">(msg);
</span><span style="color:#d3d0c8;"> }
</span><span style="color:#d3d0c8;">});
</span></pre>
</div><div data-code-theme="light"><pre style="background-color:#ffffff;">
<span style="color:#323232;">svr.WebSocket(</span><span style="color:#183691;">&quot;/ws&quot;</span><span style="color:#323232;">, [](</span><span style="font-weight:bold;color:#a71d5d;">const</span><span style="color:#323232;"> httplib::Request </span><span style="font-weight:bold;color:#a71d5d;">&amp;</span><span style="color:#323232;">req, httplib::ws::WebSocket </span><span style="font-weight:bold;color:#a71d5d;">&amp;</span><span style="color:#323232;">ws) {
</span><span style="color:#323232;"> </span><span style="font-weight:bold;color:#a71d5d;">auto</span><span style="color:#323232;"> token </span><span style="font-weight:bold;color:#a71d5d;">=</span><span style="color:#323232;"> req.get_header_value(</span><span style="color:#183691;">&quot;Authorization&quot;</span><span style="color:#323232;">);
</span><span style="color:#323232;"> </span><span style="font-weight:bold;color:#a71d5d;">if </span><span style="color:#323232;">(token.empty()) {
</span><span style="color:#323232;"> ws.close(httplib::ws::CloseStatus::PolicyViolation, </span><span style="color:#183691;">&quot;unauthorized&quot;</span><span style="color:#323232;">);
</span><span style="color:#323232;"> </span><span style="font-weight:bold;color:#a71d5d;">return</span><span style="color:#323232;">;
</span><span style="color:#323232;"> }
</span><span style="color:#323232;">
</span><span style="color:#323232;"> std::string msg;
</span><span style="color:#323232;"> </span><span style="font-weight:bold;color:#a71d5d;">while </span><span style="color:#323232;">(ws.read(msg)) {
</span><span style="color:#323232;"> ws.send(msg);
</span><span style="color:#323232;"> }
</span><span style="color:#323232;">});
</span></pre>
</div></div>
<h2>Using WSS</h2>
<p>WebSocket over HTTPS (WSS) is also supported. On the server side, just register a WebSocket handler on <code>httplib::SSLServer</code>.</p>
<div class="code-block-wrapper"><div data-code-theme="dark"><pre style="background-color:#2d2d2d;">
<span style="color:#d3d0c8;">httplib::SSLServer </span><span style="color:#6699cc;">svr</span><span style="color:#d3d0c8;">(&quot;</span><span style="color:#99cc99;">cert.pem</span><span style="color:#d3d0c8;">&quot;, &quot;</span><span style="color:#99cc99;">key.pem</span><span style="color:#d3d0c8;">&quot;);
</span><span style="color:#d3d0c8;">
</span><span style="color:#d3d0c8;">svr.</span><span style="color:#6699cc;">WebSocket</span><span style="color:#d3d0c8;">(&quot;</span><span style="color:#99cc99;">/ws</span><span style="color:#d3d0c8;">&quot;, [](</span><span style="color:#cc99cc;">const</span><span style="color:#d3d0c8;"> httplib::Request &amp;, httplib::ws::WebSocket &amp;ws) {
</span><span style="color:#d3d0c8;"> std::string msg;
</span><span style="color:#d3d0c8;"> </span><span style="color:#cc99cc;">while </span><span style="color:#d3d0c8;">(ws.</span><span style="color:#6699cc;">read</span><span style="color:#d3d0c8;">(msg)) {
</span><span style="color:#d3d0c8;"> ws.</span><span style="color:#6699cc;">send</span><span style="color:#d3d0c8;">(msg);
</span><span style="color:#d3d0c8;"> }
</span><span style="color:#d3d0c8;">});
</span><span style="color:#d3d0c8;">
</span><span style="color:#d3d0c8;">svr.</span><span style="color:#6699cc;">listen</span><span style="color:#d3d0c8;">(&quot;</span><span style="color:#99cc99;">0.0.0.0</span><span style="color:#d3d0c8;">&quot;, </span><span style="color:#f99157;">8443</span><span style="color:#d3d0c8;">);
</span></pre>
</div><div data-code-theme="light"><pre style="background-color:#ffffff;">
<span style="color:#323232;">httplib::SSLServer </span><span style="font-weight:bold;color:#795da3;">svr</span><span style="color:#323232;">(</span><span style="color:#183691;">&quot;cert.pem&quot;</span><span style="color:#323232;">, </span><span style="color:#183691;">&quot;key.pem&quot;</span><span style="color:#323232;">);
</span><span style="color:#323232;">
</span><span style="color:#323232;">svr.WebSocket(</span><span style="color:#183691;">&quot;/ws&quot;</span><span style="color:#323232;">, [](</span><span style="font-weight:bold;color:#a71d5d;">const</span><span style="color:#323232;"> httplib::Request </span><span style="font-weight:bold;color:#a71d5d;">&amp;</span><span style="color:#323232;">, httplib::ws::WebSocket </span><span style="font-weight:bold;color:#a71d5d;">&amp;</span><span style="color:#323232;">ws) {
</span><span style="color:#323232;"> std::string msg;
</span><span style="color:#323232;"> </span><span style="font-weight:bold;color:#a71d5d;">while </span><span style="color:#323232;">(ws.read(msg)) {
</span><span style="color:#323232;"> ws.send(msg);
</span><span style="color:#323232;"> }
</span><span style="color:#323232;">});
</span><span style="color:#323232;">
</span><span style="color:#323232;">svr.listen(</span><span style="color:#183691;">&quot;0.0.0.0&quot;</span><span style="color:#323232;">, </span><span style="color:#0086b3;">8443</span><span style="color:#323232;">);
</span></pre>
</div></div>
<p>On the client side, use the <code>wss://</code> scheme.</p>
<div class="code-block-wrapper"><div data-code-theme="dark"><pre style="background-color:#2d2d2d;">
<span style="color:#d3d0c8;">httplib::ws::WebSocketClient </span><span style="color:#6699cc;">client</span><span style="color:#d3d0c8;">(&quot;</span><span style="color:#99cc99;">wss://localhost:8443/ws</span><span style="color:#d3d0c8;">&quot;);
</span></pre>
</div><div data-code-theme="light"><pre style="background-color:#ffffff;">
<span style="color:#323232;">httplib::ws::WebSocketClient </span><span style="font-weight:bold;color:#795da3;">client</span><span style="color:#323232;">(</span><span style="color:#183691;">&quot;wss://localhost:8443/ws&quot;</span><span style="color:#323232;">);
</span></pre>
</div></div>
<h2>Next Steps</h2>
<p>Now you know the basics of WebSocket. This wraps up the Tour.</p>
<p>The next page gives you a summary of features we didn't cover in the Tour.</p>
<p><strong>Next:</strong> <a href="../09-whats-next">What's Next</a></p>
</article>
</main>
</div>
<footer class="footer">
&copy; 2026 yhirose. All rights reserved.
</footer>
<!-- Search modal -->
<div class="search-overlay" id="search-overlay">
<div class="search-modal">
<div class="search-input-wrap">
<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="11" cy="11" r="8"/><line x1="21" y1="21" x2="16.65" y2="16.65"/></svg>
<input type="text" id="search-input" placeholder="Search..." autocomplete="off" spellcheck="false">
<kbd class="search-esc">ESC</kbd>
</div>
<ul class="search-results" id="search-results"></ul>
</div>
</div>
<script src="&#x2F;cpp-httplib/js/main.js"></script>
</body>
</html>
Reference in New Issue View Git Blame Copy Permalink