Bash alias to list and install older versions of ports in macports

oldports.sh

# alias for bash to install older ports in macports
# (several port versions can live next to each other)
# add this code to your ~/.profile to have the
# oldports command / alias available in terminal.
#
# Usage: oldport portname
#        oldport portname version
#
# author Jeroen Wesbeek <work@osx.eu>
oldport() {
	if [ ${#@} -lt 1 ]; then
		# show help
		echo "You need to specify the port and version to install"
		echo ""
		echo "Usage:"
		echo "  oldport portname		: list all versions of a particular port"
		echo "  oldport portname version	: install this version of a particular port"
		echo "Example:"
		echo "  oldport grails 1.3.9		: install grails 1.3.9"
	else
		# search for this port and find the categories it belongs to
		PORT_CATEGORY=`port search $1|grep -i "^$1 @"|sed -e 's/.*(//' -e 's/)//' -e 's/, /\//'`
		PORT_DIR=`echo $PORT_CATEGORY|sed -e 's/\/.*//'`
		PORTFILE_URL="http://svn.macports.org/repository/macports/trunk/dports/$PORT_DIR/$1"

		# do we have one or two arguments?
		if [ ${#@} -eq 1 ]; then
			echo "The following version for $1 are available for install:"
			svn log -l 100000 $PORTFILE_URL|grep -i -e "version" -e "update"|grep "\([0-9\.]\{2,\}\)"|sed -e 's/#[0-9]\{1,\}//' -e 's/\([0-9\.]\{1,\}\)/#\1#/' -e 's/^[^#]\{0,\}#//' -e 's/#.*$//'
		else
			PORT_INSTALLED=`port installed $1|grep -i $2|wc -l`
			PORT_ACTIVE=`port installed $1|grep -i $2|grep -i "active"|wc -l`
			PORT_FULL=`port installed $1|grep -i $2|sed -e 's/.*@/@/'`
			if [ $PORT_INSTALLED -gt 0 ]; then
				if [ $PORT_ACTIVE -gt 0 ]; then
					echo "Port $1 version $2 is already installed and active."
					echo "Other installed inactive $1 versions available are:"
					echo ""
					port installed $1|grep -vi -e "(active)" -e "the following"
					echo ""
					echo "Activate another version by typing:"
					echo ""
					echo "  sudo port activate $1 @<version>"
					echo ""
				else
					echo "Port $1 version $2 is already installed but is not the"
					echo "active version. You can activate it by typing:"
					echo ""
					echo "	sudo port activate $1 $PORT_FULL"
					echo ""
				fi
			else
				REVISION=`svn log -l 1000 $PORTFILE_URL|grep --before-context=3 -i $2|grep "^r[0-9]\{1,\}"|sed -e 's/ .*//'`

				if [ $REVISION ]; then
					echo "installing $1 version $2..."
					MY_PATH=`pwd`
					cd /tmp
					rm -rf $1
					svn co -r $REVISION $PORTFILE_URL
					cd $1
					echo "enter your administrator password:"
					sudo port install
					port installed $1
					echo "switch active version by typing:"
					echo "	sudo port activate $1 @a.b.c"
					cd $MY_PATH
				else
					echo "I am sorry, there does not seem to be a $1 release for version $2 available in macports..."
					echo "You can try to install it manually by finding the changelist yourself at:"
					echo "	$PORTFILE_URL"
					echo "And use it in the steps listed here:"
					echo "	https://trac.macports.org/wiki/howto/InstallingOlderPort"
				fi
			fi
		fi
	fi
}