Functional implementation of Bash workers

workers.sh

#!/bin/bash 

set -e -o pipefail

setWaiter(){
  export maxWorkers=${1}
}

waiter(){
  while test $(jobs -p | wc -l) -ge $maxWorkers ; do wait -n ; done
}

waitall(){
  wait -n
}

# Usage
#
#
# . workers.sh
# setWaiter 3
# 
# waiter ( ls ; for ... ; otherCommand ; ) &
# 
# wait -n