title: Making curl send errors to stderr and everything else to stdout
body: <p>Is there a way to tell curl to output errors to stderr, and everything else to stdout?</p>
  
  <p>The reason is that I am using curl from the command line (actually a cronjob) to upload a file to an FTP site every evening.  Unfortunately because curl outputs status information on stderr, I receive an e-mail about an error when nothing actually went wrong.  (I'm redirecting stdout to a log file, but leaving stderr unchanged so that cron will e-mail it to me if there is any output.)</p>
  
  <p>There are options to make curl silent, or output everything to stdout, however both these alternatives prevent errors from appearing on stderr - meaning I won't get an e-mail when there is actually an error I want to know about.</p>
  
  <p>So is there a way to make curl only output errors on stderr, but leave normal output intact on stdout?</p>