title: Determine UID that last modified a file in Linux?
body: <p>I'm writing a program that will be monitoring select files and directories for changes. Some of the files are world writeable, some owner, some group.</p>
  
  <p>What I need to do is be able to figure out the last person to modify (not just access) a file. Somehow I thought this would be simple, given that we know the inode of the file .. however I can not seem to find any way of obtaining this. I thought there was a practical way of correlating any given inode to the uid last accessing it.</p>
  
  <p>I think I've squeezed google for all its going to give me on the topic.</p>
  
  <p>Any help is appreciated. I'm writing the program in C.</p>
  
  <p><strong>Edit:</strong></p>
  
  <p>I need to be able to do this after the PID of whatever program modified the file is long gone. </p>