checkRetCode ()
{
	lstRetCode=${?}
	lineNo="${1}"
	
	if [ ${lstRetCode} -ne 0 ]
	then
		echo "Last command returned and invalid code: [${lstRetCode}]. Line number: [${lineNo}]."
		exit 1
	fi
}

processUsbDev ()
{
	usbDevNamesCSV="${1}"
	baseMountPoint="${2}"
	numDirs="${3:-999}"
	numRetries="${4:-3}"

	usbDevBase="/dev"

	OIFS="${IFS}"
	IFS=","
	for usbDevName in ${usbDevNamesCSV}
	do
		usbDev="${usbDevBase}/${usbDevName}"
		
		echo "Formatting usb disk: [${usbDev}]"
		mkfs.vfat -F32 "${usbDev}"
		checkRetCode "${LINENO}"

		mountPoint="${baseMountPoint}/${usbDevName}"
		if [ ! -d "${mountPoint}" ]
		then
			mkdir "${mountPoint}"
			checkRetCode "${LINENO}"
		fi
		
		echo "Mounting disk: [${usbDev}] under: [${mountPoint}]"
		mount ${usbDev} ${mountPoint}
		checkRetCode "${LINENO}"
	done
	IFS="${OIFS}"

	countDirs=1
	countDevs=1
	
	numOfDevs=`echo "${usbDevNamesCSV}" | awk -F"," '{print NF}'`
	
	while [ ${countDirs} -le ${numDirs} ] 
	do
		[ ${countDevs} -gt ${numOfDevs} ] && countDevs=1

		countDirStr=`echo "${countDirs}" | awk '{printf("%03d\n", $0)}'`
		usbDevName=`echo "${usbDevNamesCSV}" | awk -F"," -v usbDev="${countDevs}" '{print $usbDev}'`
		
		mountPoint="${baseMountPoint}/${usbDevName}"
		createDir="${mountPoint}/${countDirStr}"
		
		echo "Creating directory under: [${mountPoint}] - [${countDirStr}][${usbDevName}]..."
		
		countRetries=0
		while true
		do
			mkdir "${createDir}"
			retCode=${?}
			if [ ${retCode} -ne 0 ]
			then
				if [ ${countRetries} -ge ${countRetries} ]
				then
					echo "Failed to create directory: [${createDir}]!"
					break
				fi
			else
				break
			fi
			countRetries=`expr ${countRetries} + 1`
		done
		
		countDevs=`expr ${countDevs} + 1`
		countDirs=`expr ${countDirs} + 1`
	done
	
	OIFS="${IFS}"
	IFS=","
	for usbDevName in ${usbDevNamesCSV}
	do
		usbDev="${usbDevBase}/${usbDevName}"
		umount ${usbDev}
		if [ ${?} -ne 0 ]
		then
			echo "Failed to umount: [${usbDev}]."
		fi
	done
	IFS="${OIFS}"
}

echo "Press any key to start!"
read

processUsbDev "sdc1,sdc2,sdc3,sdc4" "/media/usb" "999" "3"

Press any key to start!

Formatting usb disk: [/dev/sdc1]
Mounting disk: [/dev/sdc1] under: [/media/usb/sdc1]
Formatting usb disk: [/dev/sdc2]
Mounting disk: [/dev/sdc2] under: [/media/usb/sdc2]
Formatting usb disk: [/dev/sdc3]
Mounting disk: [/dev/sdc3] under: [/media/usb/sdc3]
Formatting usb disk: [/dev/sdc4]
Mounting disk: [/dev/sdc4] under: [/media/usb/sdc4]
Creating directory under: [/media/usb/sdc1] - [001][sdc1]...
Creating directory under: [/media/usb/sdc2] - [002][sdc2]...
Creating directory under: [/media/usb/sdc3] - [003][sdc3]...
Creating directory under: [/media/usb/sdc4] - [004][sdc4]...
Creating directory under: [/media/usb/sdc1] - [005][sdc1]...
Creating directory under: [/media/usb/sdc2] - [006][sdc2]...
Creating directory under: [/media/usb/sdc3] - [007][sdc3]...
Creating directory under: [/media/usb/sdc4] - [008][sdc4]...
Creating directory under: [/media/usb/sdc1] - [009][sdc1]...
Creating directory under: [/media/usb/sdc2] - [010][sdc2]...
Creating directory under: [/media/usb/sdc3] - [011][sdc3]...
Creating directory under: [/media/usb/sdc4] - [012][sdc4]...
Creating directory under: [/media/usb/sdc1] - [013][sdc1]...
Creating directory under: [/media/usb/sdc2] - [014][sdc2]...
Creating directory under: [/media/usb/sdc3] - [015][sdc3]...
Creating directory under: [/media/usb/sdc4] - [016][sdc4]...
Creating directory under: [/media/usb/sdc1] - [017][sdc1]...
Creating directory under: [/media/usb/sdc2] - [018][sdc2]...
Creating directory under: [/media/usb/sdc3] - [019][sdc3]...
Creating directory under: [/media/usb/sdc4] - [020][sdc4]...