Grails version auto-detection

I've implemented a little helper script that helps being more productive when working with multiple Grails versions. If the current working directory is a grails application, the scripts detects the version (via application.properties), sets the GRAILS_HOME environment variable and executes the appropriate Grails executable.

#!/bin/bash

GRAILS_BASE=/opt/grails
DEFAULT_VERSION="1.0.4" 

ARGS=$@           
EXECUTABLE="grails"

if [ -f application.properties ]; then                                                                             
  GRAILS_VERSION=$( cat application.properties | grep "app.grails.version=" | sed -e "s/^.*=//" | tr -d '\r\n ' )
  echo "Detected Grails $GRAILS_VERSION"  
else
  echo "Using default Grails $DEFAULT_VERSION"
  GRAILS_VERSION=$DEFAULT_VERSION
fi

GRAILS_VERSION_DIR="$GRAILS_BASE/grails-$GRAILS_VERSION"

if [ ! -d $GRAILS_VERSION_DIR ]; then
  echo "Grails Version $GRAILS_VERSION is not installed! ($GRAILS_BASE/grails-$GRAILS_VERSION)"    
  exit 1
fi

export GRAILS_HOME=$GRAILS_VERSION_DIR
$GRAILS_VERSION_DIR/bin/$EXECUTABLE $ARGS