title: Define the 64 bit width integer in Linux
body: <p>I try to define a 64 bits width integer using C language on Ubnutu 9.10. 9223372036854775808 is 2^23</p>
  
  <pre><code>long long max=9223372036854775808
  long max=9223372036854775808
  </code></pre>
  
  <p>When I compile it, the compiler gave the warning message:</p>
  
  <pre><code>binary.c:79:19: warning: integer constant is so large that it is unsigned
  binary.c: In function ‘bitReversal’:
  binary.c:79: warning: this decimal constant is unsigned only in ISO C90
  binary.c:79: warning: integer constant is too large for ‘long’ type
  </code></pre>
  
  <p>Is the long type 64 bits width?</p>
  
  <p>Best Regards,</p>