# /* vim: set filetype=sh : */
# usage: bash our shrc
##########################################################################
#    oursh : a simple learning environment for the bash shell
#    Copyright (C) 2007, Tim Menzies, tim@menzies.us, http://menzies.us
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, version 3.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
##########################################################################

Here=`pwd`

#### generic stuff
reload() { . $Ourrc;  }
show() {
	local goal1="^$1"
	local com="/^$1 /,/^}/{print}"
	if   (set | grep $goal1 | grep "=" > /tmp/debug)
   	then set  | grep $goal1
   	else set  | gawk "$com"
   	fi
}

blab()   { printf "$*"    >&2; }
blabln() { printf "$*\n" >&2; }

#### initialization stuff
setUp() {
	setUpVars
	setUpDirs
}
lcsee() {
	alias ls="ls --color"
}
setUpVars() {
	# Q0: after reading http://tldp.org/LDP/abs/html/internalvariables.html
	#     write down what "PS1", "PROMPT_COMMAND" and "PATH" do
	alias ls="ls -G"
	PS1="Our BASH!: \!$ "
	PROMPT_COMMAND='echo -ne "\033]0;${HOSTNAME}: `pwd`\007"'
	Oursh=$HOME/opt/oursh
	PATH="$Oursh/bin:$HOME/bin:$PATH"
	Safe=$Oursh/var/safe
}
setUpDirs() {
	#Q1: Aftering reading http://www.pathname.com/fhs/pub/fhs-2.3.html,
	#    write down what /opt /var /bin /lib are used for
	mkdir -p $HOME/tmp 
	mkdir -p /tmp/$USER
	Tmp=`mktemp -d -p /tmp/$USER`
	mkdir -p $Oursh/lib # for support code
	mkdir -p $Oursh/bin # for our executables
	mkdir -p $HOME/bin  # for your executables
	mkdir -p $Safe      # for stuff you want to keep around
}
demo1() {
	# Q2: After reading http://www.linux-tutorial.info/modules.php?name=MContent&pageid=20	
	#     write down what would happen if the double quotes, below, were replaced by single quotes
	echo $USER
	echo $HOME	
	echo "$USER lives in $HOME"
}
demo2() {
	# Q3: After reading http://www.linux-tutorial.info/modules.php?name=MContent&pageid=20
    #     describe how the following uses "pipes" to find all files containing the letter "a".
	ls | grep a | wc
}
demo3() {
	# Q4: After reading http://www.linux-tutorial.info/modules.php?name=MContent&pageid=20	
	#     catch the output of ls | wc.
	#     write down what would happen if the double quotes, below, were replaced by single quotes
	echo $USER
	echo $HOME	
}
demo4() {
	# Q5: After reading http://www.linux-tutorial.info/modules.php?name=MContent&pageid=20	
	#     code demo4 to captures the output of demo2 into a string, then prints the string. 
	#     Hint: back ticks
	true
}
demo5() {
	# Q6: modify the following so that "yes" is echoed if there is a file in this directory
	#     containing the word apple
	if ls | grep a > /dev/null; then
		echo yes
	else echo no
	fi
}
demo6() {
	# Q7: after reading http://www.xaprb.com/blog/2006/06/06/what-does-devnull-21-mean/
	#     write down what this code does
	wibble > /dev/null 2>&1
}
demo7() {
	# Q8: after reading http://www.xaprb.com/blog/2006/06/06/what-does-devnull-21-mean/
	#     explain what is happenning here:
	for((I=1;I<=10;I++)); do
		blabln $I
		demo5
	done  | wc	
}
demo8() {
	# Q9: after reading http://www.mktemp.org/mktemp/manual.html
	#     explain the "mktemp -d -p" command
	mktemp -d -p /tmp
}
demo9() {
	# Q10: modify the following so that you change to the $Tmp directory,
	#      generate some temp files, then trap the final report in $Safe
	for((i=1;i<=10;i++)); do 
			demo5 | wc > $i.out 
	done  	
	wc *.out 
}
demo10() {
	# Q11: after reading http://linux.byexamples.com/archives/category/common/tee/
	#      modify this demo with the "tee" command to catch the output of the "cut". 
	#      Explain the final command line	
	demo13 | cut -d, -f 4 | sort | uniq -c
}
demo11() {
	# Q12: type "man tr" at a unix prompt. Write "demo11" that turns all characters
	#      in a file to upper case
	true
}
demo12() {
	# Q13: after reading http://www.grymoire.com/Unix/Sed.html#uh-1
	#      write demo12 that turns "day" into "night"
	true
}
demo13() {
	# This is a "here" document. It is like "cat" but the contents of the file,
	#  less leading blankspace, is written to the screen
	cat<<-EOF 
	Cadillac,Large,16,25,1,1,8,4.9,200,4100,1510,0,18,6,206,114,73,43,35,18,3620,1,34.7
	Acura,Small,25,31,0,1,4,1.8,140,6300,2890,1,13.2,5,177,102,68,37,26.5,11,2705,0,15.9
	Buick,Large,16,25,1,0,6,5.7,180,4000,1320,0,23,6,216,116,78,45,30.5,21,4105,1,23.7
	Acura,Midsize,18,25,2,1,6,3.2,200,5500,2335,1,18,5,195,115,71,38,30,15,3560,0,33.9
	Audi,Midsize,19,26,2,1,6,2.8,172,5500,2535,1,21.1,6,193,106,70,37,31,17,3405,0,37.7
	Buick,Large,19,28,1,1,6,3.8,170,4800,1570,0,18,6,200,111,74,42,30.5,17,3470,1,20.8
	BMW,Midsize,22,30,1,0,4,3.5,208,5700,2545,1,21.1,4,186,109,69,39,27,13,3640,0,30
	Buick,Midsize,22,31,1,1,4,2.2,110,5200,2565,0,16.4,6,189,105,69,41,28,16,2880,1,15.7
	Buick,Midsize,19,27,1,1,6,3.8,170,4800,1690,0,18.8,5,198,108,73,41,26.5,14,3495,1,26.3
	Audi,Compact,20,26,1,1,6,2.8,172,5500,2280,1,16.9,5,180,102,67,37,28,14,3375,0,29.1
	Cadillac,Midsize,16,25,2,1,8,4.6,295,6000,1985,0,20,5,204,111,74,44,31,14,3935,1,40.1
EOF
}	
demo14() {
	# Q14: using "cut -d, ", isolate columns 1 and 4 20  from the output of demo13,
	#      using "sort -t,", sort those two columns  descending by column1 and
	#      ascending by column 20 then descending by column 4. Hint, the following is wrong
	demo13 | cut -d, -f 1 | sort -t, 
}
demo15() {
	# Q15: same as demo14 but only print the "Biuck" results : hint grep
	true
}
demo16() {
	# Q16: same as demo14 but only print lines without "Biuck" . hint man grep
	true
}
demo17() {
		#Q17: write a new version of demo5 where the "grep" runs on a user supplied
		#     paramters, called like (e.g.) demo17 b
		true
}
demo18() {
		#Q18: google "bash set +x" and find out how to trace a bash program.
		#     Hand in a trace of demo5
		true
}
demo19() {
    #Q20: show the output of this demo. explain the code, with comments. add a flag to only print the last
    #      N lines (hint: use "tail")

    local ignore="someImpossibleSYMbol"
    local sortby=2
    while [ `echo $1 | grep "-"` ]; do
       case $1 in
			-h|--help)    echo "this is the help text";;
			-v|--version) echo "demo19worker version 0.0001";;
			-s|--sortby)  sortby=$2;;
			-i|--ignore)  ignore=$2;;
			*)            blabln "'"$1"' unknown\n usage demo19workder [options]"; 
						  return 1;;
       esac
       shift 2
    done
 	ls -lsa | grep -v "$ignore" | sort   -n -k $sortby,$sortby
}

#### start up
setUp
blabln "OurSh version v0.1 (c)2007 tim@menzies.us under GPLv3"
echo "Tmp=$Tmp"
blabln "Reach out and grep someone.\n"