title: Does iOS keep file modification dates updated?
body: <p>I'm trying to determine whether (and when) a file in my app's temp file directory has been modified, but the modification date (<code>NSFileModificationDate</code> in the file attributes) seems to always match the creation date (<code>NSFileCreationDate</code>). I have some vague recollection that the file system in iOS doesn't update modification dates, but I haven't found that documented anywhere.</p>
  
  <p>Can anyone confirm (and maybe point to documentation) that iOS doesn't update modification dates?</p>
  
  <p>Also, is there some other method for determining whether a file has changed short of hashing the contents and keeping track of the result myself?</p>