title: How to use negation "?!" in grep reg exp
body: <p>I want to find all malloc functions which doesnt contain sizeof() inside the argument. So i made regular expression - <code>malloc\((?!.*sizeof\().*\);</code></p>
  
  <p>The problem is that it works at reg exp online tolls but not when i try to use it in grep. </p>
  
  <p>Example</p>
  
  <pre><code>cat file | grep "malloc\((?!.*sizeof\().*\);" 
  </code></pre>
  
  <p>ANSWER:</p>
  
  <pre><code>bash: !.sizeof\: event not found
  </code></pre>
  
  <p>Any ideas ? Maybe "?!" doesnt work in grep reg exps" ?</p>