Version 1:
su bea -c "cd /opt/local/somewhere && ./runSomeShellScript.sh"
Version 2:
su - bea -c "cd /opt/local/somewhere && ./runSomeShellScript.sh"

It took me about an hour to figure out why my installation package (which used version 1) didn’t work. Stranger because it worked flawlessly from the commandline. All *nix geeks will already have spotted the difference and LTAO my mistake.

For all others: the “-” parameter to su specifies that the user should get his own correct environemnt. Without the “-”, the new shell process will inherit the environment from the calling process (which — as it was in my case — lacked some ENVIRONMENT variables that the script excpected)

I’m one step further in my “unix-do”