My mac has folders Shared and Public folders. Their permissions are drwxr-xr-x+ for Public and drwxrwxrwt@ for Shared. What do the signs + and @ mean?
+8
A:
@ means there are "extended attributes". Type
ls -l@
to see what they are. With that command, everything with a @ after it will have some extra lines explaining why it has a @. In my experience, the @ usually means a file is going to be opened with an application other than the default (i.e. it might open with a different text editor than you're used to), or occasionally that it's in a different encoding than the default specified by $LANG.
No idea about the +. I've never run across it.
EDIT: From the manpage for "ls":
If the file or directory has extended attributes, the permissions field printed by the -l option is followed by a '@' character. Otherwise, if the file or directory has extended security information, the permissions field printed by the -l option is followed by a '+' character.
+3
A:
I'm not familiar with extended attributes, but the extended security information, aka ACLs, give more fine-grained control over file permissions. Basically, that + comes up whenever you set permissions on a file/directory beyond the usual choices of read/write/execute for user/group/other. You can see the ACLs by doing a 'ls -le'.
Jeff
2009-01-25 02:17:57