| <html> |
| <head> |
| <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> |
| <title>read_until (5 of 8 overloads)</title> |
| <link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css"> |
| <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> |
| <link rel="home" href="../../../boost_asio.html" title="Boost.Asio"> |
| <link rel="up" href="../read_until.html" title="read_until"> |
| <link rel="prev" href="overload4.html" title="read_until (4 of 8 overloads)"> |
| <link rel="next" href="overload6.html" title="read_until (6 of 8 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="overload4.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="overload6.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.overload5"></a><a class="link" href="overload5.html" title="read_until (5 of 8 overloads)">read_until |
| (5 of 8 overloads)</a> |
| </h4></div></div></div> |
| <p> |
| Read data into a streambuf until some part of the data it contains matches |
| a regular expression. |
| </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> <span class="identifier">Allocator</span><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">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">basic_streambuf</span><span class="special"><</span> <span class="identifier">Allocator</span> <span class="special">></span> <span class="special">&</span> <span class="identifier">b</span><span class="special">,</span> |
| <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span> <span class="special">&</span> <span class="identifier">expr</span><span class="special">);</span> |
| </pre> |
| <p> |
| This function is used to read data into the specified streambuf until the |
| streambuf's get area contains some data that matches a regular expression. |
| The call will block until one of the following conditions is true: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| A substring of the streambuf's get area matches the regular expression. |
| </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 streambuf's get area already contains data that |
| matches the regular expression, the function returns immediately. |
| </p> |
| <a name="boost_asio.reference.read_until.overload5.parameters"></a><h6> |
| <a name="id1298679"></a> |
| <a class="link" href="overload5.html#boost_asio.reference.read_until.overload5.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">b</span></dt> |
| <dd><p> |
| A streambuf object into which the data will be read. |
| </p></dd> |
| <dt><span class="term">expr</span></dt> |
| <dd><p> |
| The regular expression. |
| </p></dd> |
| </dl> |
| </div> |
| <a name="boost_asio.reference.read_until.overload5.return_value"></a><h6> |
| <a name="id1298750"></a> |
| <a class="link" href="overload5.html#boost_asio.reference.read_until.overload5.return_value">Return |
| Value</a> |
| </h6> |
| <p> |
| The number of bytes in the streambuf's get area up to and including the |
| substring that matches the regular expression. |
| </p> |
| <a name="boost_asio.reference.read_until.overload5.exceptions"></a><h6> |
| <a name="id1298778"></a> |
| <a class="link" href="overload5.html#boost_asio.reference.read_until.overload5.exceptions">Exceptions</a> |
| </h6> |
| <div class="variablelist"> |
| <p class="title"><b></b></p> |
| <dl> |
| <dt><span class="term">boost::system::system_error</span></dt> |
| <dd><p> |
| Thrown on failure. |
| </p></dd> |
| </dl> |
| </div> |
| <a name="boost_asio.reference.read_until.overload5.remarks"></a><h6> |
| <a name="id1298819"></a> |
| <a class="link" href="overload5.html#boost_asio.reference.read_until.overload5.remarks">Remarks</a> |
| </h6> |
| <p> |
| After a successful read_until operation, the streambuf may contain additional |
| data beyond that which matched the regular expression. An application will |
| typically leave that data in the streambuf for a subsequent read_until |
| operation to examine. |
| </p> |
| <a name="boost_asio.reference.read_until.overload5.example"></a><h6> |
| <a name="id1298849"></a> |
| <a class="link" href="overload5.html#boost_asio.reference.read_until.overload5.example">Example</a> |
| </h6> |
| <p> |
| To read data into a streambuf until a CR-LF sequence is encountered: |
| </p> |
| <pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">streambuf</span> <span class="identifier">b</span><span class="special">;</span> |
| <span class="identifier">boost</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">b</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</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">istream</span> <span class="identifier">is</span><span class="special">(&</span><span class="identifier">b</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">std</span><span class="special">::</span><span class="identifier">getline</span><span class="special">(</span><span class="identifier">is</span><span class="special">,</span> <span class="identifier">line</span><span class="special">);</span> |
| </pre> |
| <p> |
| After the <code class="computeroutput"><span class="identifier">read_until</span></code> operation |
| completes successfully, the buffer <code class="computeroutput"><span class="identifier">b</span></code> |
| contains the data which matched the regular expression: |
| </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">std</span><span class="special">::</span><span class="identifier">getline</span></code> then extracts the data up to |
| and including the match, 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> |
| 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> |
| <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 - 2010 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="overload4.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="overload6.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> |
| </div> |
| </body> |
| </html> |
