Note:  I'll make up an active learning exercise about 10 minutes before the end

Warm-up (not really review):
	Which set of notes was longest?
	What processors are on systems I can ssh into?

We talked about the file tree a bit, on a couple different occasions
	But now a tour!
	Slash direction is opposite DOS/Windows
	Case matters!
	/tmp
	/etc
	/home
	/dev and /proc
	/root (and who is root?)
	/bin, /usr, /opt, /sbin, /sys, /lib, /lib64
	/var and /var/log
	/usr/share/doc

Special characters in filenames:
	Spaces 
	/
	- (not special)
	. (not special)
		Linux does not require file extensions
		They are commonly omitted on regular text files
	~ (your home directory, if it is first)

Standard Input, Standard Output, and Standard Error
	Redirection operators on the command line

Ok, time to look at the inside
	By understanding the inside, you will understand the outside too
		When you get a new car, don't you take it to bits first thing?
	C brief intro
		Came before C++
		It's the language Linux is written in
		Standard programming language for *nix
	I'll assume you know the first 3 chapters of the C++ text
	Differences from C++:
		header files end with .h
		No namespaces
		No classes (including cin and cout)
			And string
		No standard template library
		Nested functions are ok
	C++ is nearly a proper superset of C
		No nested functions, unless you use lambda
		Struct initialization is more verbose
		Casting rules produce more warnings
	C++ has become very popular for *nix programming
		K desktop environment, for example
		It's like C, but has more features
	I'll use actual C for all examples in this class
		In CS430, you will too, because the kernel is not in C++
		You're welcome to use C++ in this class if you like!
		Less confusing if you're in CS211 at the same time
		I'll also try to make sure the examples all work in C++

File descriptors, and read/write
	write system call (what is a system call?)
	We'll open a file and write to it
	How about just using 1 as the file descriptor?
	0, 1, and 2, and write
	How about changing the file descriptor a program writes to?
		>, and file redirection
		2> redirects standard error
	
Parallel for standard in:
	It's file descriptor 0
	We can use the read system call to read from it
	

Let's make a program that just passes things through, and then redirect a file into it!
	Infinite loop, read, then write
	cat can do this.
	Maybe do something trivial, like capitalize all letters

A very useful program:  grep
	Searches through standard input or files

Permissions
	User, Group, Other
		All, which is different from other
		All is used with letters for chmod
	setuid root for programs
		Demo, with c program and system
	sticky bit and /tmp
		Undo sticky and see what happens!