title: Grep pattern matching lower case string enclosed in double quotes
body: <p>I'm having a bit of an issue with grep that I can't seem to figure out.  I'm trying to search for all instances of lower case words enclosed in double quotes (C strings) in a set of source files.  Using bash and gnu grep:</p>
  
  <pre><code>grep -e '"[a-z]+"' *.cpp
  </code></pre>
  
  <p>gives me no matches, while</p>
  
  <pre><code>grep -e '"[a-z]*"' *.cpp
  </code></pre>
  
  <p>gives me matches like "Abc" which is not just lower case characters.  What is the proper regular expression to match only "abc"?</p>