set an icon for file or folder in OS X

seticon.sh

#!/usr/bin/env sh
# Sets an icon on file or directory
# Usage setIcon.sh iconimage.jpg /path/to/[file|folder]
iconSource=$1
iconDestination=$2
icon=/tmp/`basename $iconSource`
rsrc=/tmp/icon.rsrc

# Create icon from the iconSource
cp $iconSource $icon

# Add icon to image file, meaning use itself as the icon
sips -i $icon

# Take that icon and put it into a rsrc file
DeRez -only icns $icon > $rsrc

# Apply the rsrc file to
SetFile -a C $iconDestination

if [ -f $iconDestination ]; then
    # Destination is a file
    Rez -append $rsrc -o $iconDestination
elif [ -d $iconDestination ]; then
    # Destination is a directory
    # Create the magical Icon\r file
    touch $iconDestination/$'Icon\r'
    Rez -append $rsrc -o $iconDestination/Icon?
    SetFile -a V $iconDestination/Icon?
fi

# Sometimes Finder needs to be reactivated
#osascript -e 'tell application "Finder" to quit'
#osascript -e 'delay 2'
#osascript -e 'tell application "Finder" to activate'

rm $rsrc $icon