title: invalid arithmetic operator
body: <p>working with cygwin and writing a script to show my my current ip address minus 2.  For some reason it is giving me the follwing error:  ")syntax error: invalid arithmetic operator (error token is "</p>
  
  <p>this is the script I am using.</p>
  
  <pre><code>$ cat test3.sh
  #!/bin/bash
  #
  function IPADDRESS { 
      v=$4
      echo $1.$2.$3.$((v-2)) 
  }
  ADDRESS=$(ipconfig | grep Address | cut -f2 -d :)
  # echo $ADDRESS
  IPADDRESS ${ADDRESS//\./ }
  </code></pre>
  
  <p>any help or suggestion is apprieciated!</p>