title: Change all numbers in a block of text all at once
body: <p>I have a file (pac file) that contains IP addresses for a certain corporation and want to obscure out every IP address within it. One idea I had was to add 1 to every digit in the file and mod the resulting number with 256, so that it still remains a valid IP.</p>
  
  <p>For e.g 129 will become <code>2310 % 256 = 6</code></p>
  
  <p>Is there a quick way to apply such a change using vim? It sounds ambitious, but I thought I'd still ask. Here is an example of one block from the file.</p>
  
  <pre><code>if (
  
      isInNet(ip, "111.222.123.234", "255.255.255.224")  ||
  
      isInNet(ip, "166.19.10.14", "255.255.255.192") ||
  
  
  )
  
  {return "DIRECT";}
  </code></pre>