title: Define a string in qmake command line
body: <p>I need to pass a string as a definition to my source code which is a base64 encoded string (so may contain <code>/</code> and <code>"</code>). I'm using qmake and g++. I've tried so many combinations, but neither works:</p>
  
  <pre><code>qmake DEFINES+=SERIAL=\\\"f9a/z\\\"
  qmake DEFINES+=SERIAL=\"f9a/z\"
  qmake DEFINES+="SERIAL=\\"f9a/z\\\""
  </code></pre>
  
  <p>G++ should get the serial like this:</p>
  
  <pre><code>g++ -DSERIAL=\"f9a/z\"
  </code></pre>