Sharing data: Difference between revisions

The file permissions discussed above have been available in Unix-like operating systems for decades now but they are very coarse-grained. The whole set of users is divided into just three categories: the owner, the group, and everyone else. What if I want to allow a single user who isn't in my group to read a file - do I really need to make the file readable by everyone in that case? The answer, happily, is no. Compute Canada's national systems offer "access control lists" (ACLs) to enable permissions to be set on a user-by-user basis if desired. The two commands needed to manipulate these extended permissions are