<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>DbEnv::log_printf()</title> <link rel="stylesheet" href="apiReference.css" type="text/css" /> <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> <link rel="start" href="index.html" title="Berkeley DB C++ API Reference" /> <link rel="up" href="lsn.html" title="Chapter 8. The DbLsn Handle" /> <link rel="prev" href="envlog_get_config.html" title="DbEnv::log_get_config()" /> <link rel="next" href="logput.html" title="DbEnv::log_put()" /> </head> <body> <div xmlns="" class="navheader"> <div class="libver"> <p>Library Version 11.2.5.3</p> </div> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">DbEnv::log_printf()</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="envlog_get_config.html">Prev</a> </td> <th width="60%" align="center">Chapter 8. The DbLsn Handle </th> <td width="20%" align="right"> <a accesskey="n" href="logput.html">Next</a></td> </tr> </table> <hr /> </div> <div class="sect1" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h2 class="title" style="clear: both"><a id="logprintf"></a>DbEnv::log_printf()</h2> </div> </div> </div> <pre class="programlisting">#include <db_cxx.h> int DbEnv::log_printf(DB_TXN *txnid, const char *fmt, ...);</pre> <p> The <code class="methodname">DbEnv::log_printf()</code> method appends an informational message to the Berkeley DB database environment log files. </p> <p> The <code class="methodname">DbEnv::log_printf()</code> method allows applications to include information in the database environment log files, for later review using the <a class="link" href="db_printlog.html" title="db_printlog">db_printlog</a> utility. This method is intended for debugging and performance tuning. </p> <p> The <code class="methodname">DbEnv::log_printf()</code> <span> <span> method either returns a non-zero error value or throws an exception that encapsulates a non-zero error value on failure, and returns 0 on success. </span> </span> </p> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp8282424"></a>Parameters</h3> </div> </div> </div> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="idp8355856"></a>txnid</h4> </div> </div> </div> <p> If the logged message refers to an application-specified transaction, the <span class="bold"><strong>txnid</strong></span> parameter is a transaction handle returned from <a class="xref" href="txnbegin.html" title="DbEnv::txn_begin()">DbEnv::txn_begin()</a>; otherwise NULL. </p> </div> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="idp8349960"></a>fmt</h4> </div> </div> </div> <p> A format string that specifies how subsequent arguments (or arguments accessed via the variable-length argument facilities of stdarg(3)) are converted for output. The format string may contain any formatting directives supported by the underlying C library vsnprintf(3) function. </p> </div> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp8351168"></a>Errors</h3> </div> </div> </div> <p> The <code class="methodname">DbEnv::log_printf()</code> <span> <span> method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a> exception, encapsulating one of the following non-zero errors, or return one of the following non-zero errors: </span> </span> </p> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="idp8359728"></a>EINVAL</h4> </div> </div> </div> <p> An invalid flag value or parameter was specified. </p> </div> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp8358432"></a>Class</h3> </div> </div> </div> <p> <a class="link" href="env.html" title="Chapter 5. The DbEnv Handle">DbEnv</a>, <a class="link" href="logc.html" title="The DbLogc Handle">DbLogc</a>, <a class="link" href="lsn.html" title="Chapter 8. The DbLsn Handle">DbLsn</a> </p> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp8361056"></a>See Also</h3> </div> </div> </div> <p> <a class="xref" href="lsn.html#loglist" title="Logging Subsystem and Related Methods">Logging Subsystem and Related Methods</a> </p> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="envlog_get_config.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="lsn.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="logput.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">DbEnv::log_get_config() </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> DbEnv::log_put()</td> </tr> </table> </div> </body> </html>