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<title>GnuTLS 3.5.4: Checking for an alert</title>
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<a name="Checking-for-an-alert"></a>
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<p>
Next: <a href="X_002e509-certificate-parsing-example.html#X_002e509-certificate-parsing-example" accesskey="n" rel="next">X.509 certificate parsing example</a>, Up: <a href="Miscellaneous-examples.html#Miscellaneous-examples" accesskey="u" rel="up">Miscellaneous examples</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Function-and-Data-Index.html#Function-and-Data-Index" title="Index" rel="index">Index</a>]</p>
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<hr>
<a name="Checking-for-an-alert-1"></a>
<h4 class="subsection">7.4.1 Checking for an alert</h4>
<p>This is a function that checks if an alert has been received in the
current session.
</p>
<pre class="verbatim">/* This example code is placed in the public domain. */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <gnutls/gnutls.h>
#include "examples.h"
/* This function will check whether the given return code from
* a gnutls function (recv/send), is an alert, and will print
* that alert.
*/
void check_alert(gnutls_session_t session, int ret)
{
int last_alert;
if (ret == GNUTLS_E_WARNING_ALERT_RECEIVED
|| ret == GNUTLS_E_FATAL_ALERT_RECEIVED) {
last_alert = gnutls_alert_get(session);
/* The check for renegotiation is only useful if we are
* a server, and we had requested a rehandshake.
*/
if (last_alert == GNUTLS_A_NO_RENEGOTIATION &&
ret == GNUTLS_E_WARNING_ALERT_RECEIVED)
printf("* Received NO_RENEGOTIATION alert. "
"Client Does not support renegotiation.\n");
else
printf("* Received alert '%d': %s.\n", last_alert,
gnutls_alert_get_name(last_alert));
}
}
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