shell

GNU Parallel is bundled with sem which is according to man is alias to parallel --semaphore. It limits number of simultaneously running processes. man sem is pretty simple but full of details and toilet analogies. Complex stuff could be bundled to function. #!/usr/bin/env bash myproc() { local arg="$1" echo "$(date) >>> myproc arg=$arg" sleep "$arg" echo "$(date) <<< myproc arg=$arg" } export -f myproc for i in $(seq 10 1); do sem -j4 myproc "$i" done sem --wait TADAM!...