1<!--$Id: db_set_errfile.so,v 10.10 2002/08/18 21:15:54 bostic Exp $--> 2<!--$Id: env_set_errfile.so,v 10.37 2006/10/26 15:33:59 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_errfile</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_errfile</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_errfile(FILE *errfile); 26<p> 27void Db::get_errfile(FILE **errfilep); 28</pre></b> 29<hr size=1 noshade> 30<b>Description: Db::set_errfile</b> 31When an error occurs in the Berkeley DB library, an exception is thrown or an 32error return value is returned by the interface. In some cases, 33however, the exception or returned value may be insufficient to 34completely describe the cause of the error, especially during initial 35application debugging. 36<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 37enhance the mechanism for reporting error messages to the application 38by setting a C library FILE * to be used for displaying additional Berkeley DB 39error messages. In some cases, when an error occurs, Berkeley DB will output 40an additional error message to the specified file reference.</p> 41<p>Alternatively, you can use the <a href="../api_cxx/env_set_error_stream.html">DbEnv::set_error_stream</a> method to display 42the additional information via an output stream, or the 43<a href="../api_cxx/env_set_errcall.html">DbEnv::set_errcall</a> method to capture the additional error information in 44a way that does not use either output streams or C library FILE *'s. You 45should not mix these approaches.</p> 46<p>The error message will consist of the prefix string and a colon 47("<b>:</b>") (if a prefix string was previously specified using 48<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 49a trailing <newline> character.</p> 50<p>The default configuration when applications first create <a href="../api_cxx/db_class.html">Db</a> or 51<a href="../api_cxx/env_class.html">DbEnv</a> handles is as if the <a href="../api_cxx/env_set_errfile.html">DbEnv::set_errfile</a> or 52Db::set_errfile methods were called with the standard error output 53(stderr) specified as the FILE * argument. Applications wanting no 54output at all can turn off this default configuration by calling the 55<a href="../api_cxx/env_set_errfile.html">DbEnv::set_errfile</a> or Db::set_errfile methods with NULL as the 56FILE * argument. Additionally, explicitly configuring the error output 57channel using any of the <a href="../api_cxx/env_set_errfile.html">DbEnv::set_errfile</a>, 58Db::set_errfile, <a href="../api_cxx/env_set_errcall.html">DbEnv::set_errcall</a>, 59<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 60<a href="../api_cxx/db_set_error_stream.html">Db::set_error_stream</a> methods will also turn off this default output 61for the application.</p> 62<p>This error logging enhancement does not slow performance or significantly 63increase application size, and may be run during normal operation as well 64as during application debugging.</p> 65<p>For <a href="../api_cxx/db_class.html">Db</a> handles opened inside of Berkeley DB environments, calling the 66Db::set_errfile method affects the entire environment and is equivalent to calling 67the <a href="../api_cxx/env_set_errfile.html">DbEnv::set_errfile</a> method.</p> 68<p>The Db::set_errfile method configures operations performed using the specified 69<a href="../api_cxx/db_class.html">Db</a> handle, not all operations performed on the underlying 70database.</p> 71<p>The Db::set_errfile method may be called at any time during the life of the 72application.</p> 73<b>Parameters</b> <br> 74 <b>errfile</b><ul compact><li>The <b>errfile</b> parameter is a C library FILE * to be used for 75displaying additional Berkeley DB error information.</ul> 76<br> 77<hr size=1 noshade> 78<b>Description: Db::get_errfile</b> 79<p>The Db::get_errfile method returns the FILE *.</p> 80<p>The Db::get_errfile method may be called at any time during the life of the 81application.</p> 82<p>The Db::get_errfile method 83either returns a non-zero error value 84or throws an exception that encapsulates a non-zero error value on 85failure, and returns 0 on success. 86</p> 87<b>Parameters</b> <br> 88 <b>errfilep</b><ul compact><li>The Db::get_errfile method returns the 89FILE * in <b>errfilep</b>.</ul> 90<br> 91<hr size=1 noshade> 92<br><b>Class</b> 93<a href="../api_cxx/db_class.html">Db</a> 94<br><b>See Also</b> 95<a href="../api_cxx/db_list.html">Databases and Related Methods</a> 96</tt> 97<table width="100%"><tr><td><br></td><td align=right> 98<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> 99</td></tr></table> 100<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 101</body> 102</html> 103
