An Opinionated Guide to Xargs
> I've used -P 32 to make day-long jobs take an hour! You can't do that with a for loop.    for file in *; do
      command_using_file &
    done
    wait

?I use variations on this all the time; pause while load is high, pause while 'x' or more things are running, sleep between invocations, etc.It may not be as convenient for some cases, but "can't do that..." is not quite correct either.The post is starting to feel like a hammer/nail argument, IMO.