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: DB_ENV->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>DB_ENV->log_printf</b> 14</td> 15<td align=right> 16<a href="/api_c/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.h> 23<p> 24int 25DB_ENV->log_printf(DB_ENV *env, DB_TXN *txnid, const char *fmt, ...); 26</pre></b> 27<hr size=1 noshade> 28<b>Description: DB_ENV->log_printf</b> 29<p>The DB_ENV->log_printf method appends an informational message to the Berkeley DB 30database environment log files.</p> 31<p>The DB_ENV->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 DB_ENV->log_printf method 36returns a non-zero error value on failure 37and 0 on success. 38</p> 39<b>Parameters</b> <br> 40 <b>txnid</b><ul compact><li>If the logged message refers to an application-specified transaction, 41the <b>txnid</b> parameter is a transaction handle returned from 42<a href="/api_c/txn_begin.html">DB_ENV->txn_begin</a>; otherwise NULL.</ul> 43 <b>fmt</b><ul compact><li>A format string that specifies how subsequent arguments (or arguments 44accessed via the variable-length argument facilities of stdarg(3)) are 45converted for output. The format string may contain any formatting 46directives supported by the underlying C library vsnprintf(3) 47function.</ul> 48<br> 49<br><b>Errors</b> 50<p>The DB_ENV->log_printf method 51may fail and return one of the following non-zero errors:</p> 52<br> 53<b>EINVAL</b><ul compact><li>An 54invalid flag value or parameter was specified.</ul> 55<br> 56<hr size=1 noshade> 57<br><b>Class</b> 58<a href="/api_c/env_class.html">DB_ENV</a>, <a href="/api_c/logc_class.html">DB_LOGC</a>, <a href="/api_c/lsn_class.html">DB_LSN</a> 59<br><b>See Also</b> 60<a href="/api_c/log_list.html">Logging Subsystem and Related Methods</a> 61</tt> 62<table width="100%"><tr><td><br></td><td align=right> 63<a href="/api_c/api_core.html"><img src="/images/api.gif" alt="API"></a><a href="/ref/toc.html"><img src="/images/ref.gif" alt="Ref"></a> 64</td></tr></table> 65<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 66</body> 67</html> 68