Enables/disables application saved states on OSX Lion the right way

toggle_saved_states.sh

#!/bin/bash
#Copyright 2011 Rowan Wookey https://github.com/rwky
#Released under the MIT License http://www.opensource.org/licenses/MIT
#enabled/disables application saved states in osx lion
#most tools with guis seem to lock the "Saved State" folder in
#~/Library/Saved Application State/ however not all apps
#save states there (Preview for example doesn't)
#this script uses the apple preferences to disable it which
#works on any app. To use it simply execute the script in Terminal
#with the path the the application as the first argument
if [ -z "$1" ]
then
echo "You must specify an application"
exit 1
fi

appId=$(osascript -e "id of app \"$1\"")

currentState=$(defaults read $appId NSQuitAlwaysKeepsWindows 2>/dev/null)
if [ -z $currentState ]
then
currentState=1
fi

if [ $currentState -eq 1 ]
then
echo "Disabling saved application state for $appId"
defaults write $appId NSQuitAlwaysKeepsWindows -bool false
else
echo "Enabling saved application state for $appId"
defaults write $appId NSQuitAlwaysKeepsWindows -bool true
fi