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<title>Berkeley DB: DB-&gt;set_errcall</title>
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<h3>DB-&gt;set_errcall</h3>
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<h3><pre>
#include &lt;db.h&gt;
<p>
void
DB-&gt;set_errcall(DB *,
    void (*db_errcall_fcn)(const char *errpfx, char *msg));
</pre></h3>
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<h3>Description: DB-&gt;set_errcall</h3>
<p>When an error occurs in the Berkeley DB library, a Berkeley DB error or an error
return value is returned by the interface.  In some cases, however,
the <b>errno</b> value may be insufficient to completely describe
the cause of the error, especially during initial application debugging.</p>
<p>The <a href="../api_c/env_set_errcall.html">DB_ENV-&gt;set_errcall</a> and DB-&gt;set_errcall methods are used to
enhance the mechanism for reporting error messages to the application.
In some cases, when an error occurs, Berkeley DB will call
<b>db_errcall_fcn</b> with additional error information.  It is up to
the <b>db_errcall_fcn</b> function to display the error message in an
appropriate manner.</p>
<p>Alternatively, you can use the <a href="../api_c/db_set_errfile.html">DB-&gt;set_errfile</a> or
<a href="../api_c/env_set_errfile.html">DB_ENV-&gt;set_errfile</a> methods to display the additional information via
a C library FILE *.</p>
<p>This error-logging enhancement does not slow performance or significantly
increase application size, and may be run during normal operation as well
as during application debugging.</p>
<p>For <a href="../api_c/db_class.html">DB</a> handles opened inside of Berkeley DB environments, calling the
DB-&gt;set_errcall method affects the entire environment and is equivalent to calling
the <a href="../api_c/env_set_errcall.html">DB_ENV-&gt;set_errcall</a> method.</p>
<p>The DB-&gt;set_errcall method may be called at any time during the life of the
application.</p>
<h3>Parameters</h3>
<p><dl compact>
<p><dt><b>db_errcall_fcn</b><dd>
The <b>db_errcall_fcn</b> parameter is the application-specified error
reporting function.  The function takes two parameters:
<p><dl compact>
<p><dt><b>errpfx</b><dd>The <b>errpfx</b> parameter is the prefix string (as previously set by
<a href="../api_c/db_set_errpfx.html">DB-&gt;set_errpfx</a> or <a href="../api_c/env_set_errpfx.html">DB_ENV-&gt;set_errpfx</a>).
<p><dt><b>msg</b><dd>The <b>msg</b> parameter is the error message string.
</dl>
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<h3>Class</h3>
<a href="../api_c/db_class.html">DB</a>
<h3>See Also</h3>
<a href="../api_c/db_list.html">Databases and Related Methods</a>
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