title: What do >! and >>! do in tcsh
body: <p>In normal bash redirection <code>&gt;</code> redirecting standard output to a file, overwriting when it exists and <code>&gt;&gt;</code> redirecting standard output to a file, appending when it exists.</p>
  
  <p>In a tcsh (c shell) script I found the operators <code>&gt;!</code> <code>&gt;&gt;!</code> being used. What do this operators do? tcsh does also have the <code>&gt;</code> and <code>&gt;&gt;</code> operators, so what is the difference?</p>