title: Cannot understand exec tclsh "$0" ${1+"$@"}
body: <p>I am editing my question. Before starting the PERL/tcl script i saw the following</p>
  
  <pre><code>#!/bin/sh
  # \
  exec tclsh "$0" ${1+"$@"}
  package require Expect
  </code></pre>
  
  <p>I didn't get what "exec tclsh "$0" ${1+"$@"}" this means. This is tcl script. Same thing i noticed in PERL too.</p>