title: regarding chdir in perl, how do I get back to the previous directory
body: <p>DIR1: a/b/c/d
  DIR2: e/f/g/h</p>
  
  <p>now I execute a Perl Script in DIR1 and chdir to DIR2(to use data in DIR2), after the script is executed I want to go back to DIR1. Is it default, if not then what command should be used.</p>
  
  <p>Thanks in advance.</p>