limiter

Usage: limiter <max-concurrency>

Where <max-concurrency> is the number of tasks to execute in parallel.

Tasks are pulled from stdin, and lines starting with # are skipped, so if you have a file serial.sh with:

#!/bin/bash

sleep 1
sleep 2
sleep 1
## don't forget to sleep here
sleep 6
sleep 1
sleep 1
sleep 2
#sleep 1
sleep 3
sleep 3

And you run:

limiter 3 < serial.sh

you'll see something like this: