Return the global Intake catalog dir for the current environment

def global_data_dir():
    """Return the global Intake catalog dir for the current environment"""
    prefix = False
    if VIRTUALENV_VAR in os.environ:
        prefix = os.environ[VIRTUALENV_VAR]
    elif CONDA_VAR in os.environ:
        prefix = sys.prefix
    elif which('conda'):
        # conda exists but is not activated
        prefix = conda_prefix()

    if prefix:
        # conda and virtualenv use Linux-style directory pattern
        return make_path_posix(os.path.join(prefix, 'share', 'intake'))
    else:
        return appdirs.site_data_dir(appname='intake', appauthor='intake')