title: tab-autocompletion problem in WSL(window sub linux)
body: <p>When using tab-completion in WSL(window sub linux), Some commands(cp, ls..) change prompt parameter</p>
  <pre class="lang-sh prettyprint-override"><code>example)
  define in bash_paths
    export WD=/mnt/c
  </code></pre>
  <p>When I input on prompt <code>cp $WD/</code> and then press tab, It changes <code>cp \$WD/</code>
  but I want to change to <code>cp /mnt/c/</code> and to know why does it added <code>/</code></p>
  <p>thanks for reading</p>