title: SQLite VFS implementation guide lines with FOpen*
body: <p>I am about to implement a custom VFS (virtual file system) for a Netburner embedded device (non windows) using FOpen, FRead, FWrite, FSeek, and FClose. I was surprised that i could not find a FOpen* version of the VFS available. It would make it a lot more portable to embedded devices. </p>
  
  <p>I found some information on creating the VFS for SQLite here 
  <a href="http://sqlite.org/c3ref/vfs.html" rel="nofollow noreferrer">http://sqlite.org/c3ref/vfs.html</a>
  but the information is very detailed and I have lots of other questions about the implementation. </p>
  
  <p>I have some example VFS in the SQLite source code for Win, OS2, Linux but they don't have a lot of comments, only source code. </p>
  
  <p>I could use the information provided in the link above and the examples to create my custom VFS but i'm sure that I would miss something if I did it that way. </p>
  
  <p>My questions are:</p>
  
  <ul>
  <li>Is there any more documentation about the SQLite VFS that I am missing? Maybe an implementation guide?</li>
  <li>Is there an Fopen version of the SQLite VFS that is available? </li>
  <li>Is there a unit testing code available to test my custom SQLite VFS once I have created it?</li>
  <li>Suggestions, comments, experiences with implementing SQLite VFS that you would like to share. </li>
  </ul>