collects result codes, from http://jeremy.zawodny.com/blog/archives/010717.html

parallel_bash_runner

#!/bin/bash

FAIL=0

echo "starting"

./sleeper 2 0 &
./sleeper 2 1 &
./sleeper 3 0 &
./sleeper 2 0 &

for job in `jobs -p`
do
    echo $job
    wait $job || let "FAIL+=1"
done

echo $FAIL

if [ "$FAIL" == "0" ];
then
    echo "YAY!"
else
    echo "FAIL! ($FAIL)"
fi