1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>read_until (17 of 24 overloads)</title>
<link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="../../../boost_asio.html" title="Boost.Asio">
<link rel="up" href="../read_until.html" title="read_until">
<link rel="prev" href="overload16.html" title="read_until (16 of 24 overloads)">
<link rel="next" href="overload18.html" title="read_until (18 of 24 overloads)">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr>
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td>
<td align="center"><a href="../../../../../index.html">Home</a></td>
<td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td>
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
<td align="center"><a href="../../../../../more/index.htm">More</a></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="overload16.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../read_until.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../boost_asio.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="overload18.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h4 class="title">
<a name="boost_asio.reference.read_until.overload17"></a><a class="link" href="overload17.html" title="read_until (17 of 24 overloads)">read_until
(17 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">template<
typename <a class="link" href="../SyncReadStream.html" title="Buffer-oriented synchronous read stream requirements">SyncReadStream</a>,
typename <a class="link" href="../DynamicBuffer_v2.html" title="Dynamic buffer requirements (version 2)">DynamicBuffer_v2</a>>
std::size_t read_until(
SyncReadStream & s,
DynamicBuffer_v2 buffers,
char delim,
typename enable_if< is_dynamic_buffer_v2< DynamicBuffer_v2 >::value >::type * = 0);
</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" style="list-style-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="boost_asio.reference.read_until.overload17.h0"></a>
<span class="phrase"><a name="boost_asio.reference.read_until.overload17.parameters"></a></span><a class="link" href="overload17.html#boost_asio.reference.read_until.overload17.parameters">Parameters</a>
</h6>
<div class="variablelist">
<p class="title"><b></b></p>
<dl class="variablelist">
<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="boost_asio.reference.read_until.overload17.h1"></a>
<span class="phrase"><a name="boost_asio.reference.read_until.overload17.return_value"></a></span><a class="link" href="overload17.html#boost_asio.reference.read_until.overload17.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="boost_asio.reference.read_until.overload17.h2"></a>
<span class="phrase"><a name="boost_asio.reference.read_until.overload17.exceptions"></a></span><a class="link" href="overload17.html#boost_asio.reference.read_until.overload17.exceptions">Exceptions</a>
</h6>
<div class="variablelist">
<p class="title"><b></b></p>
<dl class="variablelist">
<dt><span class="term">boost::system::system_error</span></dt>
<dd><p>
Thrown on failure.
</p></dd>
</dl>
</div>
<h6>
<a name="boost_asio.reference.read_until.overload17.h3"></a>
<span class="phrase"><a name="boost_asio.reference.read_until.overload17.remarks"></a></span><a class="link" href="overload17.html#boost_asio.reference.read_until.overload17.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="boost_asio.reference.read_until.overload17.h4"></a>
<span class="phrase"><a name="boost_asio.reference.read_until.overload17.example"></a></span><a class="link" href="overload17.html#boost_asio.reference.read_until.overload17.example">Example</a>
</h6>
<p>
To read data into a <code class="computeroutput">std::string</code> until a newline is encountered:
</p>
<pre class="programlisting">std::string data;
std::string n = boost::asio::read_until(s,
boost::asio::dynamic_buffer(data), '\n');
std::string line = data.substr(0, n);
data.erase(0, n);
</pre>
<p>
After the <code class="computeroutput">read_until</code> operation completes successfully, the
string <code class="computeroutput">data</code> contains the delimiter:
</p>
<pre class="programlisting">{ 'a', 'b', ..., 'c', '\n', 'd', 'e', ... }
</pre>
<p>
The call to <code class="computeroutput">substr</code> then extracts the data up to and including
the delimiter, so that the string <code class="computeroutput">line</code> contains:
</p>
<pre class="programlisting">{ 'a', 'b', ..., 'c', '\n' }
</pre>
<p>
After the call to <code class="computeroutput">erase</code>, the remaining data is left in the
buffer <code class="computeroutput">b</code> as follows:
</p>
<pre class="programlisting">{ 'd', 'e', ... }
</pre>
<p>
This data may be the start of a new line, to be extracted by a subsequent
<code class="computeroutput">read_until</code> operation.
</p>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><div class="copyright-footer">Copyright © 2003-2019 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></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="overload16.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../read_until.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../boost_asio.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="overload18.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
</div>
</body>
</html>
|
