title: Mac OS X Unix to find replace using regular expression
body: <p>this is my first question so apologies if this has been answered before. I have searched but cannot find what I am looking for.</p>
  
  <p>I have a huge amount of text that has been exported from a database. For certain attribute content, I need to find each instance of a space followed by a capital letter and just replace the space with a semi-colon(;).</p>
  
  <p>For example:</p>
  
  <pre><code>First one Second one Third one Fourth one
  </code></pre>
  
  <p>Should become:</p>
  
  <pre><code>First one;Second one;Third one;Fourth one
  </code></pre>
  
  <p>Using Unix (Mac OS X) The following just returns the whole line:</p>
  
  <pre><code>echo "First one Second one Third one Fourth one" | grep ' [A-Z]'
  </code></pre>
  
  <p>How would I achieve my desired outcome please? Any help or pointers would be very much appreciated.
  Thanks.</p>