title: TCL assign variable from a command
body: <p>In TCL/Expect,</p>
  
  <p>I can iterate the command line parameter in expect script.</p>
  
  <pre><code>foreach arg $argv {
      puts "This is your args: $arg"
  }
  </code></pre>
  
  <p>If I want to create a variable which store the size-of /length-of <strong>$argv</strong>
  , how do I do that? The following command doesn't seem to work.</p>
  
  <pre><code>set argSize llength $argv
  </code></pre>