Suppress Openssl output during grep
<p>I often use <code>grep</code> for openssl results when testing TLS security. For example:</p>

<pre><code>$ openssl s_client -tls1_2 -connect 172.11.15.32:443 &lt;/dev/null | grep 'IS s'
depth=0 C = US, ST = asd, O = Billing, CN = asdasd, emailAddress = root@asdasd
verify error:num=18:self signed certificate
verify return:1
depth=0 C = US, ST = asd, O = Billing, CN = asdasd, emailAddress = root@asdasd
verify return:1
DONE
Secure Renegotiation IS supported
</code></pre>

<p>However, the issue is, that no matter what I grep for, output always contains these (or similar) lines in the beginning:</p>

<pre><code>depth=0 C = US, ST = asd, O = Billing, CN = asdasd, emailAddress = root@asdasd
    verify error:num=18:self signed certificate
    verify return:1
    depth=0 C = US, ST = asd, O = Billing, CN = asdasd, emailAddress = root@asdasd
    verify return:1
</code></pre>

<p>Is it possible to somehow suppress these messages and receive only grep results as one would expect?</p>