title: Extract encrypted rar archive without showing password
body: <p>i got an idea to make something like keychain with keys, which will contain possible passwords to extract my password protected archives. So passwords will stay hidden, but user will still able to extract archive without knowing password.</p>
  
  <p>Problem is if i send password via parameter it is shown in command line parameters.</p>
  
  <pre><code>set mypass=12345
  unrar.exe x test.rar -p%mypass%
  </code></pre>
  
  <p>i tried also send pass via echo but it doesnt seems to work</p>
  
  <pre><code>@echo off
  @echo 12345 | unrar.exe x test.rar -p
  </code></pre>
  
  <p>How to solve this?</p>