Manage multiple Grails versions in development

In Grails development, it's not uncommon to maintain several projects with different Grails versions.

It's a PITA to switch between Grails versions during development. Because it requires GRAILS_HOME to be updated, to point to the correct Grails directory.


Rescue My Ass
I added 2 new bash commands to make my life easy:

• grls - list all available installed versions.
• gr <version> - set GRAILS_HOME to the specified version.

How to Use
Beech-Forkers-MacBook:~ huiming$ grls
1.1.2
1.3.2
1.3.4
1.3.6
Beech-Forkers-MacBook:~ huiming$ gr 1.3.2
Beech-Forkers-MacBook:~ huiming$ grails
Welcome to Grails 1.3.2 - http://grails.org/
Licensed under Apache Standard License 2.0
Grails home is set to: /Users/huiming/work/tools/grails

How I Implement
First, I keep all Grails installations under a same directory:
Beech-Forkers-MacBook:~ huiming$ ls -d1 work/tools/grails-*
work/tools/grails-1.1.2
work/tools/grails-1.3.2
work/tools/grails-1.3.4
work/tools/grails-1.3.6

Then, add the commands into my ~/.profile file:
TOOLS=~/work/tools

function gr {
  rm -f $TOOLS/grails && ln -s $TOOLS/grails-$1 $TOOLS/grails
}
alias grls="ls -d $TOOLS/grails-* | xargs basename | sed 's/grails-//g'"

export GRAILS_HOME=$TOOLS/grails
PATH=$GRAILS_HOME/bin:$PATH

Thanks to Jeffs, as the idea is largely based on his solution.