In this chapter, we reviewed the basics of setting ownership and permissions for files and directories. Then, we covered what SUID and SGID can do for us when they're used properly, as well as the risk of setting them on our own executable files. After looking at the two extended file attributes that deal with file security, we wrapped things up with a handy, time-saving trick for removing world-readable permissions from your system configuration files.
In the next chapter, we'll extend what we've learned here to more advanced file and directory access techniques. I'll see you there.