title: C compiler preprocessor output
body: <p><strong>C</strong> compilers supports generating the preprocessor output file with <code>.i</code> extension.<br>
  As far as I know, this is true for Microsoft (Visual Studio), ARM, Keil and some GNU compilers.</p>
  
  <p>They usually use the compiler switch <code>-E</code> or <code>-P</code> for that.<br>
  There's also the compiler switch <code>-C</code> to retain comments.</p>
  
  <p>Is the creation of preprocessor files a standard in ANSI-C, or is this compiler specific?<br>
  Is the option <code>-C</code> also a standard?</p>
  
  <p>EDIT:<br>
  To be more precise: This is about the support for creation of the <code>.i</code> file, not the compiler switch syntax or names.</p>