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