title: diff on strings, not lines
body: <p>I feel I should be able to do this in my sleep, but let's say I have two text files each of which has a single column of the names of apache modules in no particular order. One file has 46 unique (to        itself) strings. The other has 67 lines and 67 uniq (to the file) strings. There will be many strings in common.                           </p>
  
  <p>I need to find the names of apache modules that are -not- in the shorter, first file but -are- in the second, longer file.                                                                                                 </p>
  
  <p>I want to do this by searching and comparing <strong>strings</strong>. Line number, order, or postition are completely irrellevant. I just want to know which modules listed only in the longer file need to be installed.                      </p>
  
  <p>By default uniq, comm and diff want to work by lines, and line numbers.
  I don't want a side-by-side comparison; I just want a list.         </p>