1<!--$Id: db_set_error_stream.so,v 10.2 2002/08/18 21:15:54 bostic Exp $--> 2<!--$Id: env_set_error_stream.so,v 10.30 2006/02/10 22:54:59 bostic Exp $--> 3<!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> 4<!--See the file LICENSE for redistribution information.--> 5<html> 6<head> 7<title>Berkeley DB: Db::set_error_stream</title> 8<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> 9<meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> 10</head> 11<body bgcolor=white> 12<table width="100%"><tr valign=top> 13<td> 14<b>Db::set_error_stream</b> 15</td> 16<td align=right> 17<a href="../api_cxx/api_core.html"><img src="../images/api.gif" alt="API"></a> 18<a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a></td> 19</tr></table> 20<hr size=1 noshade> 21<tt> 22<b><pre> 23#include <db_cxx.h> 24<p> 25void Db::set_error_stream(class ostream*); 26</pre></b> 27<hr size=1 noshade> 28<b>Description: Db::set_error_stream</b> 29<p>When an error occurs in the Berkeley DB library, an exception is thrown or an 30<b>errno</b> value is returned by the interface. In some cases, 31however, the <b>errno</b> value may be insufficient to completely 32describe the cause of the error, especially during initial application 33debugging.</p> 34<p>The <a href="../api_cxx/env_set_error_stream.html">DbEnv::set_error_stream</a> and Db::set_error_stream methods 35are used to enhance the mechanism for reporting error messages to the 36application by setting the C++ ostream used for displaying additional 37Berkeley DB error messages. In some cases, when an error occurs, Berkeley DB will 38output an additional error message to the specified stream.</p> 39<p>The error message will consist of the prefix string and a colon 40("<b>:</b>") (if a prefix string was previously specified using 41<a href="../api_cxx/env_set_errpfx.html">DbEnv::set_errpfx</a>), an error string, and a trailing 42<newline> character.</p> 43<p>Setting <b>stream</b> to NULL unconfigures the interface.</p> 44<p>Alternatively, you can use the <a href="../api_cxx/env_set_errfile.html">DbEnv::set_errfile</a> and 45<a href="../api_cxx/db_set_errfile.html">Db::set_errfile</a> methods to display the additional information via a C 46library FILE *, or the <a href="../api_cxx/env_set_errcall.html">DbEnv::set_errcall</a> and 47<a href="../api_cxx/db_set_errcall.html">Db::set_errcall</a> methods to capture the additional error information 48in a way that does not use either output streams or C library FILE *'s. 49You should not mix these approaches.</p> 50<p>This error-logging enhancement does not slow performance or significantly 51increase application size, and may be run during normal operation as well 52as during application debugging.</p> 53<p>For <a href="../api_cxx/db_class.html">Db</a> handles opened inside of Berkeley DB environments, calling the 54Db::set_error_stream method affects the entire environment and is equivalent to calling 55the <a href="../api_cxx/env_set_error_stream.html">DbEnv::set_error_stream</a> method.</p> 56<p>The Db::set_error_stream method configures operations performed using the specified 57<a href="../api_cxx/db_class.html">Db</a> handle, not all operations performed on the underlying 58database.</p> 59<p>The Db::set_error_stream method may be called at any time during the life of the 60application.</p> 61<b>Parameters</b> <br> 62 <b>stream</b><ul compact><li>The <b>stream</b> parameter is the application-specified output stream to 63be used for additional error information.</ul> 64<br> 65<hr size=1 noshade> 66<br><b>Class</b> 67<a href="../api_cxx/db_class.html">Db</a> 68<br><b>See Also</b> 69<a href="../api_cxx/db_list.html">Databases and Related Methods</a> 70</tt> 71<table width="100%"><tr><td><br></td><td align=right> 72<a href="../api_cxx/api_core.html"><img src="../images/api.gif" alt="API"></a><a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a> 73</td></tr></table> 74<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 75</body> 76</html> 77
