From the command line in Linux, "stat" is a useful command. Good luck committing it's 30+ options to memory.... Here's the help output for easy reference to study if you're so inclined. I probably use %U and %G the most when I run into file permission issues and realized I cleared the Symfony cache accidentally…
In Linux, "cd" your way to the directory you want to completely clean out, then type:
I suggest going into the directory first, then "ls" to list the contents so you can see what you're deleting before using this command, though!
Rm –rf *