>>to elaborate: group permission is not implemented by any >>kernel file servers in the standard distribution. > > And yet, it honors "others" permissions? I can set the r > bit on others, and the cat then works...
Right. Aside from the persistent data file servers, like kfs, kenfs, and fossil (as Erik mentioned), there's not much that treats groups in the expected way. For example, all servers that use lib9p treat the group as really another user with privileges that might be different from the world. So in the case of a file that's owned by bootes bootes, the group permission is redundant. In the case of a file owned by bootes sys, then bootes gets the owner permission, the *user* sys gets the group permission and everyone else gets the world permission. Take a look at /sys/src/lib9p/uid.c to see the actual implementation. BLS
