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<head><title>dkim_set_prescreen()</title></head>
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<h1>dkim_set_prescreen()</h1>
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<!---------- Synopsis ----------->
<tr><th valign="top" align=left width=150>SYNOPSIS</th><td>
<pre>
#include <dkim.h>
<a href="dkim_stat.html"><tt>DKIM_STAT</tt></a> dkim_set_prescreen(
<a href="dkim_lib.html"><tt>DKIM_LIB</tt></a> *libopendkim,
<a href="dkim_cbstat.html">DKIM_CBSTAT</a> (*func)(<a href="dkim.html">DKIM</a> *dkim, <a href="dkim_siginfo.html">DKIM_SIGINFO</a> **sigs, int nsigs));
);
</pre>
Defines a callback function to be used for pre-scanning and sorting
signatures discovered on a message. <p>
From within <a href="dkim_eoh.html"><tt>dkim_eoh()</tt></a>, an array
of <a href="dkim_siginfo.html"><tt>DKIM_SIGINFO</tt></a> handles is
allocated, and an array of pointers is created referring to them.
If this callback function is defined, it will be called by
<tt>dkim_eoh()</tt> to give the caller a chance to review the signatures
and possibly reorder or flag them for special treatment by the library.
<tt>sigs</tt> will refer to the array of discovered signatures and
<tt>nsigs</tt> will indicate the length of this array. <p>
From within the callback you can use
<a href="dkim_sig_getcontext.html"><tt>dkim_sig_getcontext()</tt></a>
on any of the <tt>DKIM_SIGINFO</tt> pointers to retrieve the user-allocated
context specific to that signature as created earlier by the allocation
callback set by
<a href="dkim_set_signature_handle.html"><tt>dkim_set_signature_handle()</tt></a>
and make use of the data found there. That context is not used by the
library in any way. <p>
The callback can also use the function
<a href="dkim_sig_ignore.html"><tt>dkim_sig_ignore()</tt></a> to indicate
to the library that the signature should be completely ignored. <p>
The callback should return one of the
<a href="dkim_cbstat.html"><tt>DKIM_CBSTAT</tt></a> return values. Any
other value will cause <tt>dkim_eoh()</tt> to abort and return a status
of <tt>DKIM_STAT_CBINVALID</tt>. <p>
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<!----------- Description ---------->
<tr><th valign="top" align=left>DESCRIPTION</th><td>
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<th width="80">Called When</th>
<td><tt>dkim_set_prescreen()</tt> must be called before
<a href="dkim_eoh.html"><tt>dkim_eoh()</tt></a> has been called. </td>
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<!----------- Arguments ---------->
<tr><th valign="top" align=left>ARGUMENTS</th><td>
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<tr bgcolor="#dddddd"><th>Argument</th><th>Description</th></tr>
<tr valign="top"><td>libopendkim</td>
<td>The library instantiation handle, returned by
<a href="dkim_init.html"><tt>dkim_init()</tt></a>.
</td></tr>
<tr valign="top"><td>func</td>
<td>A pointer to a function which takes a <tt>DKIM</tt> handle,
a pointer to an array of <tt>DKIM_SIGINFO</tt> handles and an
integer indicating the length of that array as parameters. If
NULL, no callback will be used.
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</td></tr>
<!----------- Return Values ---------->
<tr>
<th valign="top" align=left>RETURN VALUES</th>
<td>
<ul>
<li>DKIM_STAT_OK -- success
</ul>
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<!----------- Notes ---------->
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<th valign="top" align=left>NOTES</th>
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<ul>
<li>None.
</ul>
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Copyright (c) 2007 Sendmail, Inc. and its suppliers.
All rights reserved.
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Copyright (c) 2009, 2010, The OpenDKIM Project. All rights reserved.
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