In this section, all the user management we've done in this chapter so far all comes together. We've learned how to add accounts, manage accounts, and secure them but we haven't actually done any work regarding managing the resources as far as who is able to access them. In this section, I'll give you a brief overview of how permissions work in Ubuntu Server and then I'll provide some examples for customizing them.
I'm sure by now that you understand how to list the contents of a directory with the ls command. When it comes to viewing permissions, the -l flag is especially handy, as the output that the long listing provides allows us to view the permissions of an object:
ls -l
The following are some example file listings:
-rw-rw-rw- 1 doctor doctor 5 Jan 11 12:52 welcome -rw-r--r-- 1 root root 665 Feb 19 2014 profile -rwxr-xr-x 1 dalek dalek 35125 Nov 7 2013 exterminate
In each line, we see several fields of information. The first column...