title: Unsigned int to signed in php
body: <p>It appears, that in 32bit OS <code>ip2long</code> returns signed int, and in 64bit OS unsigned int is returned.</p>
  
  <p>My application is working on 10 servers, and some are 32bit and some are 64bit, so I need all them to work same way.</p>
  
  <p>In PHP documentation there is a trick to make that result always unsigned, but since I got my database already full of data, I want to have it signed. </p>
  
  <p>So how to change an unsigned int into a signed one in PHP?</p>