title: watch grep on file doesn't work properly
body: <p>I'm trying to grep a string with spaces on file, the grep it self works great with this command:</p>
  
  <pre><code>grep ": error" makeErr.txt
  
  ...results as expected...
  </code></pre>
  
  <p>now I'm trying to put this command inside watch and it doesn't work:</p>
  
  <pre><code>watch 1 'grep ": error:" makeErr.txt'
  
  &gt; grep ": error:" makeErr.txt
  
  grep: error:": No such file or directory
  </code></pre>
  
  <p>It supposedly trying to run <code>grep ": error:" makeErr.txt</code> which is the right command, but for some reason it results in an error.
  I tried a lot of quotes variations but all results are the same.
  How do I do it properly?</p>