Relative path for relocatable Virtualenv

activate.sh

#!/bin/sh

#...

VIRTUAL_ENV=`readlink -f ${BASH_SOURCE[0]:-$0}`;
# dirname gives us the containing dir (env/bin) path
VIRTUAL_ENV=`dirname "${VIRTUAL_ENV}"`;
# we do it once again to get the upper dir
VIRTUAL_ENV=`dirname "${VIRTUAL_ENV}"`;
export VIRTUAL_ENV;