Week Five Agenda

•Link of the week•Review week four lab assignment•This week’s expected outcomes•Next lab assignment•Break-out problems•Upcoming deadlines•Questions and answers

Link of the week

Data Disaster • http://www.ontrackdatarecovery• http://hp.com.au/setlTfree/connectData Disaster

- Use dedicated circuits for your connection- Keep your computer cool and in a dry place- Use a UPS (Uninterrupted Power Supply)- Don’t assume that your data is permanently destroyed

Link of the week

Data Disaster- Big and small company operations- Backup services- Trouble shooting - Data recovery

Define: Power MonkeyDefine: Thermal Logic Technology

Review week four lab assignment• Shell Commands

catchmodcpdatefindgrepmkdirmorelessrmdirrmsortsleepwc killdiffcdwhence umask

Review week four lab assignment• Shell Arithmetic expressions

<= - less than or equal tp>= - greater than or equal to< - less than> - greater than== - equal to!= - not equal to* - multiplication/ - division+ - addition- - subtraction

• Shell statementsprintf “string” - output a string of informationecho $COUNTER - output content of the variable COUNTERprintf $NUMBER - output content of the variable NUMBERNUMBER=$(($NUMBER-1)) - decrease NUMBER value by one$# - number of positional parameters$? - return value$$ - prosess id of this shell$! - bachground process id

Review week four lab assignment• Shell Conditional Expression Primitives

-r - true if file exists and is readable-w - true if file exists and is writable-x - true if file exists and is executable-f - true if file exists and is a file-d - true if file exists and is a directory-eq - true if value of exp1 and exp2 are equal-ne - true if value of exp1 and exp2 are not equal-gt - true if value of exp1 is greater than value of exp2 -ge - true if value of exp1 is greater than or equal to value of exp2-lt - true if value of exp1 is less than value of exp2 -le - true if value of exp1 less than or equal to value of exp2

• Shell Quoting ‘ …’ - single literal quotes“…” - double quotes (interpolation allowed)`…` - single back ticks (command execution)

Review week four lab assignment• Shell I/O Redirection

< variable - read from file (cat < test_file)> variable - write to a file (cat > test_file)variable >> variable - append content of file_1 to the end of file_2 (cat file_1 >> file_2)

• Shell Syntaxwhile [ … ]do

…doneif [ … ]then

…fiif [ … ]then

…elif

…fi

test –r “$test_file”test x+1 –gt y

Review week four lab assignment

• Perl Binary Arithmetic Operators

+ - addition ($a + $b)* - multiplication ($a * $b)% - modulus (remainder of $a divided by $b)** - exponentiation ($a raised to the power of $b)

• Perl Comparison Operators== - equal!= - not equal< - less than> - greater than<= - less than or equal>= - greater than or equal - comparison (0 if equal, 1 if $variable_1 greater, -1 if

$variable_2 greater

Review week four lab assignment

• Perl Comparison Operatorseq - equalne - not equallt - less thangt - greater thanle - less than or equalge - greater than or equalcmp - comparison (0 if equal, 1 if $variable_1 greater, -1 if

$variable_2 greater• Perl Conditional Expression Primitives

-e $var - true if file $var exists-r $var - true if file $var is readable-w $var - true if file $var is writable-d $var - true if $var is a directory-f $var - true if file $var is a file-T $var - true if file $var is a text file

Review week four lab assignment• Perl Quotes

“ “ double-quotes‘ ‘ single-quotes` ` backtick-quotes

• Perl String Operators$arrayexp[0]=“string assignment”; (string assignment to zero element of array)$cmdexp=`ls –l`; (string output from a command)$charexp=‘b’; (string character assignment)$strexp=“string assignment”; (string assignment)$intexp=150; (an integer)$str_int=“I have two $pets”; (string with interpolation)

• Perl Commandschopunlessprint $varpop

Review week four lab assignment

• Perl Variable Syntax$ singular variables prefix (single value, number or string)@ prefix for plural variable (array)% prefix for plural variable (hash)$_ default variable

• Relational Operators• Equality Operators

Review week four lab assignment • Perl Syntax

while ( … ){

…}If ( …) {

…}

If ( … ){

…}else{

…}

Review week four lab assignment

• Perl Syntax; end of statement delimiter, comma for line continuation \n new line

Weeks four and five expected outcomes

• Write Perl scripts, including variables, control flow, and regular expression syntax

Next lab assignmentProgramming Perl, Chapter 32 Standard ModulesDefine: ModuleParsing the command line with Getopt::StdExample: listdir –l –n –a 10:00 bottom topPerl utilizes @ARGV to capture the command line

argumentsExample: $ARGV[0] ‘-l’

$ARGV[1] ‘-n’ $ARGV[2] ‘-a’ $ARGV[3] ’10:00’ $ARGV[4] ‘bottom’ $ARGV[5] ‘top’

Next lab assignment

• Perl Array@garage = (“rake”, “mower”, “shovel”);($rake, $mower, $shovel) = @garage

• Perl Hash%colormap=(

“12” => “gray”,“19” => “black”,“30” => “red”,);

%colormap = (“12”, “gray”, “19”, “black”, “30”, “red”);

Break-out problems

• Global variable• Boolean• Binary• Executable file• Execute bit• fork command• Portable• Object file• System call• Data structure

Upcoming deadlines• Simple Perl Script, 5-1 is due 6/1/08.• Makefile Exercise, 7-2 is due 6/15/08.• Mid-term exam dates 6/9/08 through 6/14/08.• Programming Assignment 1, 6-1 is due 6/22/08.

- Script logic for the above assignment will be emailed at the end of the week.

• Reading AssignmentEssential System Administration

Chapter One, pages 1 -8, 12 – 28Chapter Two, pages 32 – 61Chapter Three

Programming PerlChapter OneChapter Two, pages 47 – 65, 69 – 73, 76 - 83 Chapter Three, pages 86 – 90, 92 -101Chapter Thirty Two, pages 865 – 867, 899

Questions and answers• Questions• Comments• Concerns

• After class I will help students with their scripts.