Finds Volumes of some external drives and writes a random byte to a /.nosleep file

nosleep.sh

#!/bin/bash

while true
do
	re="/dev/disk[2-9][0-9]?s[0-9][0-9]? on ([^\(]+)" 		# Matches volumes on disk2sX or higher
	mounts=`mount`
	mounts2=$mounts
	date
	while [[ ${mounts} =~ (${re}) ]]
	do
		nosleep=`echo ${BASH_REMATCH[2]}|xargs`/.nosleep 	# xargs strips trailing spaces
		echo Writing $nosleep
		head -c1 /dev/random >"$nosleep"
		mounts=${mounts##*${BASH_REMATCH[1]}} 				# substring removal
	done

	re2="[^\(]+ on ([^\(]+)[^\)]*zfs" 						# Matches ZFS volumes
	while [[ ${mounts2} =~ (${re2}) ]]
	do
		nosleep=`echo ${BASH_REMATCH[2]}|xargs`/.nosleep 	# xargs strips trailing spaces
		echo Writing $nosleep
		head -c1 /dev/random >"$nosleep"
		mounts2=${mounts2##*${BASH_REMATCH[1]}} 			# substring removal
	done
	sleep 60
done