seq 10 20 | xargs -n 1 -P 5 sleep

This will send a sequence of numbers to xargs, which will divide it into chunks of one argument at a time and fork off 5 parallel processes to execute each. You can see it in action:

$ ps -eaf | grep sleep
baron     5830  5482  0 11:12 pts/2    00:00:00 xargs -n 1 -P 5 sleep
baron     5831  5830  0 11:12 pts/2    00:00:00 sleep 10
baron     5832  5830  0 11:12 pts/2    00:00:00 sleep 11
baron     5833  5830  0 11:12 pts/2    00:00:00 sleep 12
baron     5834  5830  0 11:12 pts/2    00:00:00 sleep 13
baron     5835  5830  0 11:12 pts/2    00:00:00 sleep 14

There are basically unlimited uses for this!

Further Reading:

• Introducing MySQL Parallel Dump
• How to check and optimize MySQL tables in parallel
• Introducing MySQL Parallel Restore
• How I keep track of tasks
• How to read Linux’s /proc/diskstats easily