FIRST UNIX SESSION

	ssh cs313@wolf.cs.wustl.edu
	w
	who
	whoami
	top (CTRL-C)
	df
	pwd
	ls
	ls -1 | wc
	ls -lt | head -10 
	ls -lt | head -10 | wc
	ls -lt | tail -10 | wc
	ls | less (SPACE, ENTER, j, k, q)
	ls -s
	ls -l
	du
	clear
	exit

SECOND UNIX SESSION

	ssh cs313@wolf.cs.wustl.edu
	mkdir loui04
	cd loui04
	find .. -name words
	find .. -name words | gawk '{system("cp "$1" words"++n)}'
	ls
	ls -s
	diff words3 words4
	less words3 (/ate, /ate$)
	grep 'ate$' words3
	grep 'ate$' words3 > words5
	vi words5 (:g/./ s/ate$/ated, :wq)

	REVIEW REGEXPS
		.
		.*
		[a-z]*
		[^a-z]
		^
		$
		[0-9]+
		^	[1-9]\.
		[1-9][0-9]*\.?[0-9]*
		[aeiou][^aeiou][aeiou]
		<[^>]*>

	vi insulter0.awk (i, ESC, :wq)

		BEGIN {
		  while (getline < "words5") w[n++] = $1
		  while (1) {
		    print "You are so damned "w[int(rand()*n)]"."
		    getline # your turn
		  }
		}

	gawk -f insulter0.awk (CTRL-C)
	vi insulter0.awk (/while, O, ESC, :wq)

		srand()

	vi insulter0.awk (O, ESC, :wq)

		#! /bin/gawk -f

	chmod a+rx insulter0.awk
	ls -l insulter0.awk
	./insulter0.awk

	cp words4 words5
	alias cp
	alias cp 'cp -i'
	!grep
	echo > words5
	!grep
	^words5^words4
	!!:s/words4/words5
	history
	top (CTRL-Z)
	jobs
	kill -9 25327
	top (CTRL-Z)
	fg (CTRL-C)
	cd ~
	ls -a

	spell.awk

		BEGIN { 
		  while (getline < "words") w[$1] = 1
		}
		{ 
		  for (i=1; i<=NF; i++) 
		    if (!w[$i]) 
		      print $i " is misspelled!" 
		}

	or

		BEGIN { while (getline < "words") w[$1] = 1 }
		{ for (i=1; i<=NF; i++) if (!w[$i]) print $i " is misspelled!" }


GAWK HIGHLIGHTS
	autotyping of variables (is this a string context or numeric?)
	autoinitialization (if string, then "", if numeric, then 0)
	implicit operation on lines {}, preceded by BEGIN{} section
	automatic parsing of input into $1, $2, ... using field separator FS
	file and pipe handles are strings
	there is no concatenation operator
	arrays are all associative, and all indexed by strings, automanaged
	statements or statement blocks {}
	semi-colon is optional, and used to group multiple statements on a line
	# produces a comment to the end of the line
	man gawk is a good read

FIRST DAY WITH VI

	ESC puts you in command-mode (if you happen to be in insert-mode)
	:vi puts you in visual-mode (if you happen to be in colon-mode)

	VI is based on a COMMAND GRAMMAR

	:w	writes the file
	:w!	writes the file, over an existing file
	:q	quits
	:q!	quits, discarding changes
	:wq	writes and quits
	:wq!	writes and quits, over an existing file
	:w fn	writes the file as fn
	:w! fn	overwrites the file as fn

	:n	edits the next file (e.g. % vi foo* )
	:g/bah/ s/foo/bar	goes to every line matching bah
				substitutes first foo with bar

	COMMANDS ENTERING INSERT-MODE

	a	append after current char
	i	insert before current char
	A	append after current line
	I	insert before current line
	s	substitute this character
	c$	change from here to end of line
	c0	change from here to beginning of line
	cw	change this word
	c3w	change the next three words
	cfn	change from here until you find an n, including the n
	ctn	change from here until you find an n, excluding the n
	c3fn	change from here until you find the third n, including
	c3tn	change from here until you find the third n, excluding
	o	open a line below this line
	O	open a line above this line

	COMMAND TO EXIT INSERT-MODE

	ESC

	COMMANDS THAT CHANGE CHARACTERS

	r	replaces this character for the next one typed
	R	replaces characters until ESC

	BASIC MOTION

	0	move to first character on line
	$	move to last character on line
	w	move forward a word
	b	move back a word
	e	move to end of word
	h,j,k,l	left,down,up,right
	-	up
	ENTER	down
	G	go to last line
	1G	go to first line
	11|	go to 11th column
	fn	find an n in the line
	tn	find before an n in the line
	;	repeat f or t command
	/fooENTER	find next occurrence of foo (across lines)
	?	reverse / command
	?fooENTER	find previous occurrence of foo (across lines)
	n	repeat / or ? command