title: External commands from Vim are not recognized, including 'ls' and 'pwd'
body: <p>I'm still learning vim and during my vimtutor session I wrote <code>:!ls</code> but it couldn't be found. I've also tried <code>:sh</code> which works fine but I can't figure out why using the bang symbol wouldn't</p>
  
  <p>edit: I was wrong. ':sh' brings up the shell but ls and pwd still don't work with that instance of the shell</p>
  
  <p>edit2: I've been using Powershell and realize now that <code>ls</code> and <code>pwd</code> are not commands available to cmd. I added</p>
  
  <pre><code>set shell=powershell.exe
  set shellcmdflag=-c
  set shellpipe=&gt;
  set shellredir=&gt;
  </code></pre>
  
  <p>into _vimrc gleamed from this question: <a href="https://stackoverflow.com/questions/94382/vim-with-powershell">Vim with Powershell</a></p>