title: How to run git status without modifying .git/index - such as in a PROMPT_COMMAND
body: <p>I've got a PROMPT_COMMAND that shows git branch information using git status, unfortunately when 'git status' is invoked, it appears to be modifying the .git/index file. </p>
  
  <p>This is not good since if you are running with a user that has rights over the target directory (such as on a shared filesystem or if you're running as a privileged account) - it winds up changing the ownership of that file to your user since git appears to be recreating the .git/index file. </p>
  
  <p>Is there any way to run 'git status' that will keep it from modifying the .git/index file?</p>