tmp=/tmp/$$
keyind=$1; valind=$2; infile=${3:-'-'};
mkfifo $tmp-infile.count $tmp-infile.sum $tmp-count $tmp-sum
cat $infile  |
tee $tmp-infile.count > $tmp-infile.sum &
SHELL/count $keyind $tmp-infile.count  > $tmp-count &
SHELL/sum $keyind $valind $tmp-infile.sum > $tmp-sum &
join -1 1 -2 1 $tmp-count $tmp-sum |
awk '{ print $1, $3 / $2 }'
rm $tmp-*
