title: how to pass the user-defined macro to xcodebuild?
body: <p>I build my project by xcodebuild in command line. Not in xCode. I want to pass some marc to the project so that it can affect the code.  Such as code below:</p>
  
  <pre><code>#if (API_TYPE == 1)
    #define URL_API @"https://dapi.xxx.com/1.1/"
  #elif (API_TYPE == 2)
    #define URL_API @"https://tapi.xxx.com/1.1/"
  #elif (API_TYPE == 3)
    #define URL_API @"https://api.xxx.com/1.1/"
  #else
    #error "API_TYPE value error! should be only value 1,2,3 !"
  #endif 
  </code></pre>
  
  <p>I want pass the define of API_TYPE outside the code files. Such as through xcodebuild command.
  But It doesn't work like this:</p>
  
  <pre><code>xcodebuild -sdk xxx -target xxx SYMROOT=${XCSYMROOT} API_TYPE=${APITYPE}
  </code></pre>
  
  <p>The API_TYPE's value was not changed. But the SYMROOT's value was changed.
  So how can I implement that passing the value to API_TYPE outside ?   </p>