1<!--$Id: env_set_errfile.so,v 10.37 2006/10/26 15:33:59 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_errfile</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_errfile</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 25DbEnv::set_errfile(FILE *errfile); 26<p> 27void 28DbEnv::get_errfile(FILE **errfilep); 29</pre></b> 30<hr size=1 noshade> 31<b>Description: DbEnv::set_errfile</b> 32When an error occurs in the Berkeley DB library, an exception is thrown or an 33error return value is returned by the interface. In some cases, 34however, the exception or returned value may be insufficient to 35completely describe the cause of the error, especially during initial 36application debugging. 37<p>The <a href="../api_cxx/env_set_errcall.html">DbEnv::set_errcall</a> and <a href="../api_cxx/db_set_errcall.html">Db::set_errcall</a> methods are used to 38enhance the mechanism for reporting error messages to the application 39by setting a C library FILE * to be used for displaying additional Berkeley DB 40error messages. In some cases, when an error occurs, Berkeley DB will output 41an additional error message to the specified file reference.</p> 42<p>Alternatively, you can use the <a href="../api_cxx/env_set_error_stream.html">DbEnv::set_error_stream</a> method to display 43the additional information via an output stream, or the 44<a href="../api_cxx/env_set_errcall.html">DbEnv::set_errcall</a> method to capture the additional error information in 45a way that does not use either output streams or C library FILE *'s. You 46should not mix these approaches.</p> 47<p>The error message will consist of the prefix string and a colon 48("<b>:</b>") (if a prefix string was previously specified using 49<a href="../api_cxx/db_set_errpfx.html">Db::set_errpfx</a> or <a href="../api_cxx/env_set_errpfx.html">DbEnv::set_errpfx</a>), an error string, and 50a trailing <newline> character.</p> 51<p>The default configuration when applications first create <a href="../api_cxx/db_class.html">Db</a> or 52<a href="../api_cxx/env_class.html">DbEnv</a> handles is as if the DbEnv::set_errfile or 53<a href="../api_cxx/db_set_errfile.html">Db::set_errfile</a> methods were called with the standard error output 54(stderr) specified as the FILE * argument. Applications wanting no 55output at all can turn off this default configuration by calling the 56DbEnv::set_errfile or <a href="../api_cxx/db_set_errfile.html">Db::set_errfile</a> methods with NULL as the 57FILE * argument. Additionally, explicitly configuring the error output 58channel using any of the DbEnv::set_errfile, 59<a href="../api_cxx/db_set_errfile.html">Db::set_errfile</a>, <a href="../api_cxx/env_set_errcall.html">DbEnv::set_errcall</a>, 60<a href="../api_cxx/db_set_errcall.html">Db::set_errcall</a>, <a href="../api_cxx/env_set_error_stream.html">DbEnv::set_error_stream</a> or 61<a href="../api_cxx/db_set_error_stream.html">Db::set_error_stream</a> methods will also turn off this default output 62for the application.</p> 63<p>This error logging enhancement does not slow performance or significantly 64increase application size, and may be run during normal operation as well 65as during application debugging.</p> 66<p>The DbEnv::set_errfile method configures operations performed using the specified 67<a href="../api_cxx/env_class.html">DbEnv</a> handle, not all operations performed on the underlying 68database environment.</p> 69<p>The DbEnv::set_errfile method may be called at any time during the life of the 70application.</p> 71<b>Parameters</b> <br> 72 <b>errfile</b><ul compact><li>The <b>errfile</b> parameter is a C library FILE * to be used for 73displaying additional Berkeley DB error information.</ul> 74<br> 75<hr size=1 noshade> 76<b>Description: DbEnv::get_errfile</b> 77<p>The DbEnv::get_errfile method returns the FILE *.</p> 78<p>The DbEnv::get_errfile method may be called at any time during the life of the 79application.</p> 80<p>The DbEnv::get_errfile method 81either returns a non-zero error value 82or throws an exception that encapsulates a non-zero error value on 83failure, and returns 0 on success. 84</p> 85<b>Parameters</b> <br> 86 <b>errfilep</b><ul compact><li>The DbEnv::get_errfile method returns the 87FILE * in <b>errfilep</b>.</ul> 88<br> 89<hr size=1 noshade> 90<br><b>Class</b> 91<a href="../api_cxx/env_class.html">DbEnv</a> 92<br><b>See Also</b> 93<a href="../api_cxx/env_list.html">Database Environments and Related Methods</a> 94</tt> 95<table width="100%"><tr><td><br></td><td align=right> 96<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> 97</td></tr></table> 98<p><font size=1>Copyright (c) 1996,2008 Oracle. 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