libdb/docs/api_reference/CXX/envset_error_stream.html
2011-12-19 19:07:10 -05:00

164 lines
7.2 KiB
HTML
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>DbEnv::set_error_stream()</title>
<link rel="stylesheet" href="apiReference.css" type="text/css" />
<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
<link rel="start" href="index.html" title="Berkeley DB C++ API Reference" />
<link rel="up" href="env.html" title="Chapter 5.  The DbEnv Handle" />
<link rel="prev" href="envset_errfile.html" title="DbEnv::set_errfile()" />
<link rel="next" href="envset_errpfx.html" title="DbEnv::set_errpfx()" />
</head>
<body>
<div xmlns="" class="navheader">
<div class="libver">
<p>Library Version 11.2.5.2</p>
</div>
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center">DbEnv::set_error_stream()</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="envset_errfile.html">Prev</a> </td>
<th width="60%" align="center">Chapter 5. 
The DbEnv Handle
</th>
<td width="20%" align="right"> <a accesskey="n" href="envset_errpfx.html">Next</a></td>
</tr>
</table>
<hr />
</div>
<div class="sect1" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both"><a id="envset_error_stream"></a>DbEnv::set_error_stream()</h2>
</div>
</div>
</div>
<pre class="programlisting">#include &lt;db_cxx.h&gt;
void DbEnv::set_error_stream(class ostream*); </pre>
<p>
When an error occurs in the Berkeley DB library, an exception
is thrown or an <span class="bold"><strong>errno</strong></span> value
is returned by the interface. In some cases, however, the
<span class="bold"><strong>errno</strong></span> value may be
insufficient to completely describe the cause of the error,
especially during initial application debugging.
</p>
<p>
The <code class="methodname">DbEnv::set_error_stream()</code> and
<a class="xref" href="dbset_error_stream.html" title="Db::set_error_stream()">Db::set_error_stream()</a>
methods are used to enhance the mechanism for reporting error messages to the
application by setting the C++ ostream used for displaying
additional Berkeley DB error messages. In some cases, when an
error occurs, Berkeley DB will output an additional error message
to the specified stream.
</p>
<p>
The error message will consist of the prefix string and a colon
("<span class="bold"><strong>:</strong></span>") (if a prefix string was
previously specified using
<a class="xref" href="dbset_errpfx.html" title="Db::set_errpfx()">Db::set_errpfx()</a>,
an error string, and a trailing &lt;newline&gt; character.
</p>
<p>
Setting <span class="bold"><strong>stream</strong></span> to NULL unconfigures the interface.
</p>
<p>
Alternatively, you can use the
<a class="xref" href="envset_errfile.html" title="DbEnv::set_errfile()">DbEnv::set_errfile()</a> or
<a class="xref" href="dbset_errfile.html" title="Db::set_errfile()">Db::set_errfile()</a> methods
to display the additional information via a C Library <code class="literal">FILE *</code>,
or the <a class="xref" href="envset_errcall.html" title="DbEnv::set_errcall()">DbEnv::set_errcall()</a>
and <a class="xref" href="dbset_errcall.html" title="Db::set_errcall()">Db::set_errcall()</a>
methods to capture the additional error information in a way that does not use either
output streams or C Library <code class="literal">FILE *</code>'s.
You should not mix these approaches.
</p>
<p>
This error-logging enhancement does not slow performance or significantly increase
application size, and may be run during normal operation as well as during application
debugging.
</p>
<p>
The <code class="methodname">DbEnv::set_error_stream()</code> method configures operations
performed using the specified <a class="link" href="env.html" title="Chapter 5.  The DbEnv Handle">DbEnv</a> handle,
not all operations performed on the underlying database environment.
</p>
<p>
The <code class="methodname">DbEnv::set_error_stream()</code> method may be called at any time during the
life of the application.
</p>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="id3603128"></a>Parameters</h3>
</div>
</div>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id3603131"></a>stream</h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>stream</strong></span> parameter is the
application-specified output stream to be used for additional error
information.
</p>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="id3602900"></a>Class</h3>
</div>
</div>
</div>
<p>
<a class="link" href="env.html" title="Chapter 5.  The DbEnv Handle">DbEnv</a>
</p>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="id3602943"></a>See Also</h3>
</div>
</div>
</div>
<p>
<a class="xref" href="env.html#envlist" title="Database Environments and Related Methods">Database Environments and Related Methods</a>
</p>
</div>
</div>
<div class="navfooter">
<hr />
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left"><a accesskey="p" href="envset_errfile.html">Prev</a> </td>
<td width="20%" align="center">
<a accesskey="u" href="env.html">Up</a>
</td>
<td width="40%" align="right"> <a accesskey="n" href="envset_errpfx.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">DbEnv::set_errfile() </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> DbEnv::set_errpfx()</td>
</tr>
</table>
</div>
</body>
</html>