CS 227 lecture -*- Outline -*-

* Unix survival skills
** what is it?
	a computer has many *resources*
		disk (files), the network, monitor, CPU (time), memory, etc.
	if there is more than one user, need to allocate these resources
	even if not more than one user, want to have these resources
		controlled in such a way that most programs don't have to
		worry about the details

	def: an operating system is a program that controls the resources
		of a computer
	e.g., Unix, DOS, System 7, VMS

*** layers of an OS (Unix)
	(draw picture)
		shell and other built-in programs (file system commands, ...)
		kernel (manages the hardware and provides essentials)
		hardware and other resources

	strictly speaking the O.S. doesn't include the shell, etc.
		but most people talk that way

*** login ids (user name)
	since Unix is a multiuser O.S., need some identity to allocate
		resources to
	login id associates you (a person)
                         to an account (machine's rep of person)

*** account
	which the id identifies
	like an office, password is its lock

	don't give anyone else the lock
	don't let anyone else in the office (to set it up)

** logging in and logging out (PV 3.2)
*** logging in
	distinguish workstation case from terminal case
		will be showing terminal case
	password doesn't echo
*** setting the terminal type (PV 3.2.5)
	usually won't have to do this except on a terminal
	answer the TERM = (vt100) prompt
		OR (later)
	set term=vt100
		good for most dial ups
		or whatever kind of terminal (xterm, vt200, adm3a)
*** correcting typing mistakes
	use DEL (the delete or <X key) which is the unix "erase" character
	use C-c to interrupt what you are doing (unix "intr" character)
		use "stty -a" to see settings
		if not right use "stty erase '^?' intr '^C'" to restore them
	if you are used to backspace for erasing,
		either get used to DEL, because that works in emacs
		OR learn how to swap DEL and C-h in emacs (see newsgroup)
	show what happens if they do C-h in scheme

*** going home
	click on STOP sign on a workstation
	logout or C-d on a terminal

** the file system
	files are the most important resource,
		at least the one you have to think about most

*** files
------------------
  THE UNIX FILE SYSTEM

 * files (parts of the disk with data)
   - inode (owner, group, permissions,
            access & modification times,
            size, disk address, ...)
   - data

 * directories
	mapping from names to files
                      or directories

 * file names
   - string of characters except /
   - case matters (FOO, Foo, foo)
   - patterns *, ?

 * directory names
   - . (current directory)
   - .. (parent directory)
   - / (root directory)

 * current directory
        what directory your process is in
-------------------

	directory is like a shelf (can have shelves on shelves)
		or filing cabinet
	file is like a book on the shelf
		or a file folder's contents

*** exploring (quickly)
	go exploring in my directory and in /home/scheme
		emphasize cd (2 cases), pwd
			  ., ..
			  ls, ls -l (inode info)
*** making directories, removing them
	mkdir, rmdir (in /home/scheme/meeting-transcripts)
		e.g. hw1
*** creating and editing files using emacs (PV 4.2)
	use emacs
**** starting emacs
	on workstation, use
		emacs &
	runs emacs in the background
**** exiting emacs: C-x C-c
	getting out of emacs
*** running the emacs tutorial
	control and meta combinations
	do a little of cursor movements

	they need to do it themselves

	getting more help
		C-h
		info (on-line manual)

*** emacs and the ISN
	See Getting to and Using Project Vincent Without a Workstation handout

	C-s stops (freezes) output
	C-q thaws it
	Need to use M-x isn-mode
		swaps C-s and C-\
		      C-q and C-^
		that is to type what would have been C-s, you can then type C-\


** mail
	Skipped in 1993, as done in "lesson vincent" well enough
*** sending mail using comp (PV 11.1.6)
	try comp, send mail to a TA
	emphasize:
		in emacs
		fill in Subject: field
		message after the ---------
		sign it!
*** reading mail (PV 11.1)
	inc
	show [n]
	next
	repl	to reply
	scan

	see man mh for more details

*** create a tiny scheme file
	(define delta-E
	  (lambda (force distance)
	    (* force distance)))

*** run the whos-on-first program
	(load "/home/cs227/lib/whos-on-first.ss")

** getting more help on unix
	man (and xman on workstations)
	man -k (keyword) to find out about commands (e.g., lprm, lpq)

	olc and olc answers