title: How to grep a vector and return a single TRUE or FALSE?
body: <p>Is there a <code>grep</code> function in R that returns <code>TRUE</code> if a pattern is found anywhere in the given character vector and <code>FALSE</code> otherwise?</p>
  
  <p>All the functions I see return a <em>vector</em> of the current positions of each element found.</p>