- xdg-data-dirs #!key (set-environment? #t)procedure
Return the value of the XDG_DATA_DIRS environment variable if it is set and is not empty. Otherwise return "/usr/local/share/:/usr/share/".
By default, this procedure sets the XDG_DATA_DIRS environment variable with its return value in case the environment variable is not set. This behavior can be disabled by binding the set-environment? keyword parameter to #f).