title: How can I access a user-defined Xcode build setting?
body: <p>If I added a user-defined setting in my build configuration, how can I read that setting in my Objective-C code?</p>
  
  <p>I have two files in my project, <code>debug.plist</code> and <code>release.plist</code>. I want my <code>MainApp.m</code> file to read one of these files based on which build configuration is running. I set up a user-defined setting named "filename" in both the Debug and Release configurations to point to the appropriate file. But I don't know how my <code>MainApp.m</code> file can read the filename variable from the current running configuration.</p>