title: regex ip address from string
body: <p>gcc 4.6.2 c89</p>
  
  <p>Is there any standard regex expression that can be used to extract the IP address from a string.</p>
  
  <p>I am thinking about using sscanf with a regex expression to get the IP from this sample string below.</p>
  
  <p>This is the sample string:</p>
  
  <pre><code>v=0 o=sip_user IN 10230 22472 IP4 NET.CAT.NTBC s=SIP_CALL c=IN IP4 10.10.10.44 m=audio 49152 RTP/AVP 0 a=rtpmap:0 PCMU/8000
  </code></pre>
  
  <p>So the regex will be in between the quotes:</p>
  
  <pre><code>sscanf(ip_string, "%s", &amp;ip_address);
  </code></pre>
  
  <p>Many thanks for any suggestions,</p>