You want to set up a shared folder on the same Mac, like iTunes or Aperture, so your family can share the same files. Let’s assume you have a group called “staff”; which everybody is already in, and a folder called “common”. This is a mac, this should be simple, right? well.. almost with a bit of terminal-fu:
FOLDER=common GROUP=staff mkdir $FOLDER chown -R $USER $FOLDER chown -R :$GROUP $FOLDER chmod -R g+rw $FOLDER chmod -RN $FOLDER chmod -RI $FOLDER chmod -R +a '$GROUP allow list,add_file,search,delete,\ add_subdirectory,delete_child,file_inherit,directory_inherit' \ $FOLDER ls -lde $FOLDER
You can use the slightly more permissive
'$GROUP allow list,add_file,search, \ delete,add_subdirectory,delete_child,readattr,writeattr,readextattr, \ writeextattr,readsecurity,file_inherit,directory_inherit'
which allows that group to change permissions and ACLs as well.
chown -R :staffchanges the standard unix group
-RIremove any inherited and initial ACLs; this is not needed for new folders but if you are converting an existing folder, this helps a lot to clean up crap
chmod -R +athis is the permissions-mojo being applied
ls -ldedisplays the extended permissions for a folder note that the ACLs must not have spaces in them if you are pasting code from above