[opensuse-buildservice] service_add macro

Hi, I'd like to generate a package for different distributions using OBS. The package requires to create a user and install a service. Via a search engine, I found this PDFs: http://files.opensuse.org/opensuse/en/9/9b/LinuxTag2006_Build_Service_2.pdf http://files.opensuse.org/opensuse/en/5/57/FOSDEM_building.pdf But when I use user_group_add, I get following error: fg: no job control Are these macros supported by OBS or the distributions? Is there an example package? Are was this just an idea and I have to write if clauses for every distribution (openSUSE, Fedora, Mandriva) Thanks, Florian