162 lines
12 KiB
HTML
162 lines
12 KiB
HTML
<html>
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
|
|
<title>read_until (1 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="../read_until.html" title="read_until">
|
|
<link rel="next" href="overload2.html" title="read_until (2 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="../read_until.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="overload2.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.overload1"></a><a class="link" href="overload1.html" title="read_until (1 of 24 overloads)">read_until (1
|
|
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"><</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_v1.html" title="Dynamic buffer requirements (version 1)">DynamicBuffer_v1</a><span class="special">></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">&</span> <span class="identifier">s</span><span class="special">,</span>
|
|
<span class="identifier">DynamicBuffer_v1</span> <span class="special">&&</span> <span class="identifier">buffers</span><span class="special">,</span>
|
|
<span class="keyword">char</span> <span class="identifier">delim</span><span class="special">,</span>
|
|
<span class="keyword">typename</span> <span class="identifier">constraint</span><span class="special"><</span> <span class="identifier">is_dynamic_buffer_v1</span><span class="special"><</span> <span class="keyword">typename</span> <span class="identifier">decay</span><span class="special"><</span> <span class="identifier">DynamicBuffer_v1</span> <span class="special">>::</span><span class="identifier">type</span> <span class="special">>::</span><span class="identifier">value</span> <span class="special">>::</span><span class="identifier">type</span> <span class="special">=</span> <span class="number">0</span><span class="special">,</span>
|
|
<span class="keyword">typename</span> <span class="identifier">constraint</span><span class="special"><</span> <span class="special">!</span><span class="identifier">is_dynamic_buffer_v2</span><span class="special"><</span> <span class="keyword">typename</span> <span class="identifier">decay</span><span class="special"><</span> <span class="identifier">DynamicBuffer_v1</span> <span class="special">>::</span><span class="identifier">type</span> <span class="special">>::</span><span class="identifier">value</span> <span class="special">>::</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.overload1.h0"></a>
|
|
<span><a name="asio.reference.read_until.overload1.parameters"></a></span><a class="link" href="overload1.html#asio.reference.read_until.overload1.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 character.
|
|
</p></dd>
|
|
</dl>
|
|
</div>
|
|
<h6>
|
|
<a name="asio.reference.read_until.overload1.h1"></a>
|
|
<span><a name="asio.reference.read_until.overload1.return_value"></a></span><a class="link" href="overload1.html#asio.reference.read_until.overload1.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.overload1.h2"></a>
|
|
<span><a name="asio.reference.read_until.overload1.exceptions"></a></span><a class="link" href="overload1.html#asio.reference.read_until.overload1.exceptions">Exceptions</a>
|
|
</h6>
|
|
<div class="variablelist">
|
|
<p class="title"><b></b></p>
|
|
<dl>
|
|
<dt><span class="term">asio::system_error</span></dt>
|
|
<dd><p>
|
|
Thrown on failure.
|
|
</p></dd>
|
|
</dl>
|
|
</div>
|
|
<h6>
|
|
<a name="asio.reference.read_until.overload1.h3"></a>
|
|
<span><a name="asio.reference.read_until.overload1.remarks"></a></span><a class="link" href="overload1.html#asio.reference.read_until.overload1.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.overload1.h4"></a>
|
|
<span><a name="asio.reference.read_until.overload1.example"></a></span><a class="link" href="overload1.html#asio.reference.read_until.overload1.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 newline 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="char">'\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">'\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">'\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="../read_until.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="overload2.html"><img src="../../../next.png" alt="Next"></a>
|
|
</div>
|
|
</body>
|
|
</html>
|