title: Fortran execute_command_line does not return result
body: <p>I need to create a file in fortran and then read the data in the file.</p>
  
  <pre><code>call execute_command_line('pwd &gt; workdir.dat')
  
  open(unit=10, file='workdir.dat', status='replace', IOSTAT=open_stat)
      if (open_stat /= 0) stop "Reading workdir.dat file Error"
      read(10,"(A)") workdir
  close(10)
  </code></pre>
  
  <p>However, <code>workdir.dat</code> is empty when I try to open it, giving me serious open error. It seems that the system only flush the content of <code>workdir.dat</code> to the file at the end of the program. How do I make sure <code>workdir.dat</code> is ready to use before <code>open</code> ?</p>