Yes, that's would I just programmed.
So I am answering my own stupid question with this little script called check_races
#!/bin/ksh
rc=$(echo races | er_print $1 2> /dev/null | grep 'Total Races: 0' > /dev/null 2>&1 )
return $rc
and then in the Makefile:
check_races races.er || rdt races.er
Thanks
Dieter