$ENV{http_proxy} = $proxy
   if defined($proxy);

sub RunChild {
   my ($call, $url) = @_;

   my $logFile = $logDir."/header_".$call;
   open(local *CHLD_STDERR, '>>', $logFile)
      or die("Can't open log file $logFile: $!\n");

   exec(
      curl => (
         -o => '/dev/null',
         -m => '222',
         $url,
      )
   );

   die("Can't launch curl: $!\n");
}