tri11paragon
/
Insane_DNS
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
Insane_DNS/libraries/asio-1.28.1/doc/asio/reference/read_until/overload19.html

148 lines
10 KiB
HTML
Raw Blame History

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>read_until (19 of 24 overloads)</title>
<link rel="stylesheet" href="../../../boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
<link rel="home" href="../../../index.html" title="Asio">
<link rel="up" href="../read_until.html" title="read_until">
<link rel="prev" href="overload18.html" title="read_until (18 of 24 overloads)">
<link rel="next" href="overload20.html" title="read_until (20 of 24 overloads)">
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr><td valign="top"><img alt="asio C++ library" width="250" height="60" src="../../../asio.png"></td></tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="overload18.html"><img src="../../../prev.png" alt="Prev"></a><a accesskey="u" href="../read_until.html"><img src="../../../up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../home.png" alt="Home"></a><a accesskey="n" href="overload20.html"><img src="../../../next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h4 class="title">
<a name="asio.reference.read_until.overload19"></a><a class="link" href="overload19.html" title="read_until (19 of 24 overloads)">read_until (19
of 24 overloads)</a>
</h4></div></div></div>
<p>
Read data into a dynamic buffer sequence until it contains a specified
delimiter.
</p>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span>
<span class="keyword">typename</span> <a class="link" href="../SyncReadStream.html" title="Buffer-oriented synchronous read stream requirements">SyncReadStream</a><span class="special">,</span>
<span class="keyword">typename</span> <a class="link" href="../DynamicBuffer_v2.html" title="Dynamic buffer requirements (version 2)">DynamicBuffer_v2</a><span class="special">&gt;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">read_until</span><span class="special">(</span>
<span class="identifier">SyncReadStream</span> <span class="special">&amp;</span> <span class="identifier">s</span><span class="special">,</span>
<span class="identifier">DynamicBuffer_v2</span> <span class="identifier">buffers</span><span class="special">,</span>
<span class="identifier">string_view</span> <span class="identifier">delim</span><span class="special">,</span>
<span class="keyword">typename</span> <span class="identifier">constraint</span><span class="special">&lt;</span> <span class="identifier">is_dynamic_buffer_v2</span><span class="special">&lt;</span> <span class="identifier">DynamicBuffer_v2</span> <span class="special">&gt;::</span><span class="identifier">value</span> <span class="special">&gt;::</span><span class="identifier">type</span> <span class="special">=</span> <span class="number">0</span><span class="special">);</span>
</pre>
<p>
This function is used to read data into the specified dynamic buffer sequence
until the dynamic buffer sequence's get area contains the specified delimiter.
The call will block until one of the following conditions is true:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
The get area of the dynamic buffer sequence contains the specified
delimiter.
</li>
<li class="listitem">
An error occurred.
</li>
</ul></div>
<p>
This operation is implemented in terms of zero or more calls to the stream's
read_some function. If the dynamic buffer sequence's get area already contains
the delimiter, the function returns immediately.
</p>
<h6>
<a name="asio.reference.read_until.overload19.h0"></a>
<span><a name="asio.reference.read_until.overload19.parameters"></a></span><a class="link" href="overload19.html#asio.reference.read_until.overload19.parameters">Parameters</a>
</h6>
<div class="variablelist">
<p class="title"><b></b></p>
<dl>
<dt><span class="term">s</span></dt>
<dd><p>
The stream from which the data is to be read. The type must support
the SyncReadStream concept.
</p></dd>
<dt><span class="term">buffers</span></dt>
<dd><p>
The dynamic buffer sequence into which the data will be read.
</p></dd>
<dt><span class="term">delim</span></dt>
<dd><p>
The delimiter string.
</p></dd>
</dl>
</div>
<h6>
<a name="asio.reference.read_until.overload19.h1"></a>
<span><a name="asio.reference.read_until.overload19.return_value"></a></span><a class="link" href="overload19.html#asio.reference.read_until.overload19.return_value">Return
Value</a>
</h6>
<p>
The number of bytes in the dynamic buffer sequence's get area up to and
including the delimiter.
</p>
<h6>
<a name="asio.reference.read_until.overload19.h2"></a>
<span><a name="asio.reference.read_until.overload19.remarks"></a></span><a class="link" href="overload19.html#asio.reference.read_until.overload19.remarks">Remarks</a>
</h6>
<p>
After a successful read_until operation, the dynamic buffer sequence may
contain additional data beyond the delimiter. An application will typically
leave that data in the dynamic buffer sequence for a subsequent read_until
operation to examine.
</p>
<h6>
<a name="asio.reference.read_until.overload19.h3"></a>
<span><a name="asio.reference.read_until.overload19.example"></a></span><a class="link" href="overload19.html#asio.reference.read_until.overload19.example">Example</a>
</h6>
<p>
To read data into a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code>
until a CR-LF sequence is encountered:
</p>
<pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">data</span><span class="special">;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">n</span> <span class="special">=</span> <span class="identifier">asio</span><span class="special">::</span><span class="identifier">read_until</span><span class="special">(</span><span class="identifier">s</span><span class="special">,</span>
<span class="identifier">asio</span><span class="special">::</span><span class="identifier">dynamic_buffer</span><span class="special">(</span><span class="identifier">data</span><span class="special">),</span> <span class="string">"\r\n"</span><span class="special">);</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">line</span> <span class="special">=</span> <span class="identifier">data</span><span class="special">.</span><span class="identifier">substr</span><span class="special">(</span><span class="number">0</span><span class="special">,</span> <span class="identifier">n</span><span class="special">);</span>
<span class="identifier">data</span><span class="special">.</span><span class="identifier">erase</span><span class="special">(</span><span class="number">0</span><span class="special">,</span> <span class="identifier">n</span><span class="special">);</span>
</pre>
<p>
After the <code class="computeroutput"><span class="identifier">read_until</span></code> operation
completes successfully, the string <code class="computeroutput"><span class="identifier">data</span></code>
contains the delimiter:
</p>
<pre class="programlisting"><span class="special">{</span> <span class="char">'a'</span><span class="special">,</span> <span class="char">'b'</span><span class="special">,</span> <span class="special">...,</span> <span class="char">'c'</span><span class="special">,</span> <span class="char">'\r'</span><span class="special">,</span> <span class="char">'\n'</span><span class="special">,</span> <span class="char">'d'</span><span class="special">,</span> <span class="char">'e'</span><span class="special">,</span> <span class="special">...</span> <span class="special">}</span>
</pre>
<p>
The call to <code class="computeroutput"><span class="identifier">substr</span></code> then
extracts the data up to and including the delimiter, so that the string
<code class="computeroutput"><span class="identifier">line</span></code> contains:
</p>
<pre class="programlisting"><span class="special">{</span> <span class="char">'a'</span><span class="special">,</span> <span class="char">'b'</span><span class="special">,</span> <span class="special">...,</span> <span class="char">'c'</span><span class="special">,</span> <span class="char">'\r'</span><span class="special">,</span> <span class="char">'\n'</span> <span class="special">}</span>
</pre>
<p>
After the call to <code class="computeroutput"><span class="identifier">erase</span></code>,
the remaining data is left in the buffer <code class="computeroutput"><span class="identifier">b</span></code>
as follows:
</p>
<pre class="programlisting"><span class="special">{</span> <span class="char">'d'</span><span class="special">,</span> <span class="char">'e'</span><span class="special">,</span> <span class="special">...</span> <span class="special">}</span>
</pre>
<p>
This data may be the start of a new line, to be extracted by a subsequent
<code class="computeroutput"><span class="identifier">read_until</span></code> operation.
</p>
</div>
<div class="copyright-footer">Copyright © 2003-2023 Christopher M. Kohlhoff<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
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>)
</p>
</div>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="overload18.html"><img src="../../../prev.png" alt="Prev"></a><a accesskey="u" href="../read_until.html"><img src="../../../up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../home.png" alt="Home"></a><a accesskey="n" href="overload20.html"><img src="../../../next.png" alt="Next"></a>
</div>
</body>
</html>
Reference in New Issue View Git Blame Copy Permalink