We take a look at how standard Unix File Permissions work, and look at how to understand the permissions on existing files and folders, but not at how to change them. We also cover the fact that the standard unix file permissions are now only a sub-set of the file permissions on OS X and Linux (OS X also supports file ACLs, and Linux has SELinux as an optional extra layer of security).

As always, you can get to Bart's fabulous tutorial shownotes at ttt.bartificer.net/...