Cheesy example of how to do "bash threads" keeping a limit on the number executing at once.

bash_threads.sh

#!/bin/bash

#
# Credit goes to Pulu! http://www.linkedin.com/pub/pulu-anau/b/5b4/345
#

MAX_JOBS=5

function run_process ()
{
	echo "Running Process $1" 
	#echo "Test STDOUT for this job... RUNNING PROCESS $1" > $1.txt
	sleep 1

}

for i in {1..50}
do
	run_process $i &

	while [ `jobs | wc -l` -ge $MAX_JOBS ]
	do
		sleep 1
	done

done

wait