my $pid=spawn("/usr/bin/ps","test1.out");

waitpid($pid,0);

print "test1.out not created" if not -e "test1.out";

#
# More code
#

sub spawn {
 my($cmd,$redirect)=@_;

  my $pid=fork();
  return $pid if $pid > 0;
  if ( $pid == 0 ) {
        # Child process
        exec sprintf("%s > %s",$cmd,$redirect)
             or die "Could not exec $cmd:$!";
   } else { 
        # uh-oh... could not fork
        die "Could not fork $cmd : $!";
   }
}