title: php Validate latitude/longitude strings in decimal format
body: <p>Alright I have what I would call a massive list of longitude and latitude coordinates. That said I also have a handful of sources I pull these coordinates in from. Some of them come from get/post methods which can cause potential security holes in my site/service. So I am trying to figure out how to validate longitude and latitude via PHP. I was thinking something regex via preg_match. But I could be wrong, maybe there's an easier way someone would like to suggest. I've tried my own concepts, and I have tried various internet brew concepts of trying to find a regex pattern that will validate these for me via preg_match (or similar again if you got a better suggestion I am all ears).</p>
  
  <p>My Last failed attempt prior to finally caving in and coming here was..</p>
  
  <pre><code>preg_match('^(\-?\d+(\.\d+)?),\s*(\-?\d+(\.\d+)?)$', $geoResults['latitude']))
  </code></pre>
  
  <p>which yields " preg_match() [function.preg-match]: No ending delimiter '^' found " as my error. Last couple attempts I have tried yielded that error so I have no idea what it is or means. </p>