title: time command with flags running application with flags
body: <p>Im trying to time my little program, which uses MPI and I want the output in a file.</p>
  
  <p>The command Im trying: <code>time --output=rt.txt mpirun -np 2 a.out</code>.  But the flags for <code>time</code>and  <code>mpirun</code> seem to  clash.</p>
  
  <p>Any ideas how this might work?</p>