title: Obfuscated C Code Contest 2006. Please explain sykes2.c
body: <p>How does this C program work?</p>
  
  <pre><code>main(_){_^448&amp;&amp;main(-~_);putchar(--_%64?32|-~7[__TIME__-_/8%8]["&gt;'txiZ^(~z?"-48]&gt;&gt;";;;====~$::199"[_*2&amp;8|_/64]/(_&amp;2?1:8)%8&amp;1:10);}
  </code></pre>
  
  <p>It compiles as it is (tested on <code>gcc 4.6.3</code>). It prints the time when compiled. On my system:</p>
  
  <pre><code>    !!  !!!!!!              !!  !!!!!!              !!  !!!!!! 
      !!  !!  !!              !!      !!              !!  !!  !! 
      !!  !!  !!              !!      !!              !!  !!  !! 
      !!  !!!!!!    !!        !!      !!    !!        !!  !!!!!! 
      !!      !!              !!      !!              !!  !!  !! 
      !!      !!              !!      !!              !!  !!  !! 
      !!  !!!!!!              !!      !!              !!  !!!!!!
  </code></pre>
  
  <p>Source: <a href="http://www.ioccc.org/years-spoiler.html#2006" rel="noreferrer">sykes2 - A clock in one line</a>, <a href="http://www.ioccc.org/2006/sykes2/hint.text" rel="noreferrer">sykes2 author hints</a></p>
  
  <p>Some hints: No compile warnings per default. Compiled with <code>-Wall</code>, the following warnings are emitted:</p>
  
  <pre><code>sykes2.c:1:1: warning: return type defaults to ‘int’ [-Wreturn-type]
  sykes2.c: In function ‘main’:
  sykes2.c:1:14: warning: value computed is not used [-Wunused-value]
  sykes2.c:1:1: warning: implicit declaration of function ‘putchar’ [-Wimplicit-function-declaration]
  sykes2.c:1:1: warning: suggest parentheses around arithmetic in operand of ‘|’ [-Wparentheses]
  sykes2.c:1:1: warning: suggest parentheses around arithmetic in operand of ‘|’ [-Wparentheses]
  sykes2.c:1:1: warning: control reaches end of non-void function [-Wreturn-type]
  </code></pre>