1<!--$Id: log_printf.so,v 1.1 2005/09/30 19:00:24 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::log_printf</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::log_printf</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> 24int 25DbEnv::log_printf(DB_TXN *txnid, const char *fmt, ...); 26</pre></b> 27<hr size=1 noshade> 28<b>Description: DbEnv::log_printf</b> 29<p>The DbEnv::log_printf method appends an informational message to the Berkeley DB 30database environment log files.</p> 31<p>The DbEnv::log_printf method allows applications to include information in 32the database environment log files, for later review using the 33<a href="../utility/db_printlog.html">db_printlog</a> utility. This method is intended for debugging and 34performance tuning.</p> 35<p>The DbEnv::log_printf method 36either returns a non-zero error value 37or throws an exception that encapsulates a non-zero error value on 38failure, and returns 0 on success. 39</p> 40<b>Parameters</b> <br> 41 <b>txnid</b><ul compact><li>If the logged message refers to an application-specified transaction, 42the <b>txnid</b> parameter is a transaction handle returned from 43<a href="../api_cxx/txn_begin.html">DbEnv::txn_begin</a>; otherwise NULL.</ul> 44 <b>fmt</b><ul compact><li>A format string that specifies how subsequent arguments (or arguments 45accessed via the variable-length argument facilities of stdarg(3)) are 46converted for output. The format string may contain any formatting 47directives supported by the underlying C library vsnprintf(3) 48function.</ul> 49<br> 50<br><b>Errors</b> 51<p>The DbEnv::log_printf method 52may fail and throw 53<a href="../api_cxx/except_class.html">DbException</a>, 54encapsulating one of the following non-zero errors, or return one of 55the following non-zero errors:</p> 56<br> 57<b>EINVAL</b><ul compact><li>An 58invalid flag value or parameter was specified.</ul> 59<br> 60<hr size=1 noshade> 61<br><b>Class</b> 62<a href="../api_cxx/env_class.html">DbEnv</a>, <a href="../api_cxx/logc_class.html">DbLogc</a>, <a href="../api_cxx/lsn_class.html">DbLsn</a> 63<br><b>See Also</b> 64<a href="../api_cxx/log_list.html">Logging Subsystem and Related Methods</a> 65</tt> 66<table width="100%"><tr><td><br></td><td align=right> 67<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> 68</td></tr></table> 69<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 70</body> 71</html> 72