title: do post processing after make install in cmake
body: <p>I am trying to make a copy of my executable at the end of my"make install"</p>
  
  <p>I need to do something like:</p>
  
  <pre><code>cp bin/prog bin/prog1
  </code></pre>
  
  <p>I have added the following as the last line in my CMakelists.txt</p>
  
  <pre><code>install (CODE  "execute_process(COMMAND /src/copyExe.sh ${BIN_DIR})")
  </code></pre>
  
  <p>copyExe.sh is a bash script that does the copying.  In order to have the desired affect, I need to run "make install" twice.  The first time it complains that prog doesn't exist, and then copies the file to bin.  The second time it finds prog and is able to make the copy.</p>
  
  <p>Is there a way to ensure that my copyExe script runs AFTER the files get copied to bin?</p>
  
  <p>Directory structure</p>
  
  <pre><code>site
      bin
      src
          CMakeLists.txt ( contains add_dir(foo) and install(CODE....))
      foo
          CMakeLists.txt ( contains install( TARGET..... ))
  </code></pre>