Version comparison in Bash, by Seagate

postinstall.sh

function cmpvers()
{
	if [ "$1" == "$2" ]
	then
		echo 0
	else
		if [ -z "$2" ]
		then
			echo 1
		else
			if [ -z "$1" ]
			then
				echo -1
			else
				if [ "$( versF1 $1 )" -ne "$( versF1 $2 )" ]
				then
					if [ "$( versF1 $1 )" -gt "$( versF1 $2 )" ]
					then
						echo 1
					else
						echo -1
					fi
				else
					if [ "$( versF2 $1 )" -ne "$( versF2 $2 )" ]
					then
						if [ "$( versF2 $1 )" -gt "$( versF2 $2 )" ]
						then
							echo 1
						else
							echo -1
						fi
					else
						if [ "$( versF3 $1 )" -ne "$( versF3 $2 )" ]
						then
							if [ "$( versF3 $1 )" -gt "$( versF3 $2 )" ]
							then
								echo 1
							else
								echo -1
							fi
						else
							echo 0
						fi
					fi
				fi
			fi
		fi
	fi
}