Post on 23-Mar-2016
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Week Six Agenda• Announcements• Link of the week• Review week four lab assignment• This week’s expected outcomes• Next lab assignment• Review midterm exam• Break-out problems• Upcoming deadlines• Lab assistance, questions and answers
Link of the week http://www.cert.org/homeusers/HomeComputerSecurity/
This Wed site provides useful information how to secure your home computer, things you ought to know, and what should be done to secure a home computer.
http://www.istl.org/02-fall/internet.html
Science and Technology Resources on the InternetComputer Security
This article is written by Jane F. KinKus, who is a Mathematical Sciences Librarian.
Link of the week• Define: Trusted System is on that is replied
upon to a specific extent to enforce a specific security policy.
• Define: Trusted Computing means that a computer will consistently behave in specific ways, and those behaviors will be enforced by hardware and software.
• Where are trusted systems utilized? Homeland security, law enforcement, and social control
Review week five lab assignmentkill commandUsed to send a signal to another process.PID An integer used by the UNIX kernel to uniquely
identify a process. PIDs are returned by the fork system call and can be passed to wait() or kill() to perform actions on the given process.
test_build.shThis script is used to execute the make command
which in turn calls the makefile.test_build.sh -> make -> makefile
Review week five lab assignment
SourceFile
SourceFile
SourceFile
SourceFile
SourceFile
Object File
Object File
ObjectFile
Object File
ObjectFile
LinkerRuntimeLibrary
ExecutableProgram
Source/Object/Executable Drawing
Review week five lab assignmentDefine make command: The make utility is a software engineering tool for
managing and maintaining computer programs. Make provides most help when the program consists of many component files. As the number of files in the program increases so to does the compile time, complexity of compilation command and the likelihood of human error when entering command lines, i.e. typos and missing file names.
Review week five lab assignment
Define the makefile: Make goes through the makefile (descriptor) file
first starting with the target it is going to create. Make looks at each of the target’s dependencies to see if they are listed as targets. It follows the chain of dependencies until it reaches the end of the chain and then begins backing out executing the commands found in each target's rule. Actually every file in the chain may not need to be compiled. Make looks at the time stamp for each file in the chain and compiles from the point that is required to bring every file in the chain up to date. If any file is missing it is updated if possible.
•
Review week five lab assignmentMakefile Components
• Comments within a makefile (#)• makefile continuation lines (\)• Rule tells make both when and how to make a
file• Dependency Line is a line with a colon (:) test_build.sh contains the make command
which calls the makefile. The test_build.sh script is located in the /tmp directory.
• Demonstrate makefile script under ~dandrear/temp (cs.franklin.edu)
Review week five lab assignment
Key Points About makefile 1. Makefile recompiles all source files for an
entire project.2. Makefile recompiles only those files that
have different time stamps.3. Bottom up control flow.4. Rules are shell commands.
Review week five lab assignmentOther software products that perform similar bundling operations
- ANT developed by Apache Jakarta- ANT2 supplied from the Free Software
Foundation which is part of Red Hat.
What is a dependency between source files?main.cpp employee.cpp address.cpp
What are the two parts of a dependency rule? 1) What files a file is dependent on
2) Rule that tells how to recompile the fileWhat are the differences between a makefile and a shell script?The rules in a makefile are executed based on dependency, and
not sequential order. Scripts execute in sequential order.
Review week five lab assignmentTarget : Dependencies (prerequisites)<tab> Rule prog: a.o b.o c.o g++ -o a.o b.o c.oa.o: prog.h a.c g++ –c prog.h a.cb.o: prog.h b.c g++ –c prog.h b.cc.o: c.c
g++ –c c.cc.c: c.y
g++ -c c.ymv y_table.c c.y
Review week five lab assignment
Review week five lab assignmentmyProgram
main.o employee.o address.o
employee.cppemployee.h main.cpp address.haddress.cpp
Review week five lab assignmentKey Points About Perl1. Dynamic typing2. Dynamic allocation of memory for arrays
and hash tables3. Both procedural and object oriented
programming capabilities4. Rich third party software and use of
modules
Review week five lab assignment• Regular expression (a.k.a. regex or regexp)
Is a pattern that describes a certain amount of text. A basic regular expression could be the single character, e.g.: a
Jane is a women.
It will match the first occurrence in the string. If succeeding matches are desired, the regex engine must be instructed to do so.
Review week five lab assignmentRegular Expression Special Characters * Open square bracket [ * Backslash \
* Caret ^* Dollar sign $* Dot .Pipe symbol |Question mark ?Asterisk ** Plus sign +Opening and closing round brackets ( )
Review week five lab assignmentAwk Script# Author: Bob D'Andrea# Script name: awksrc# Command line awk -f awksrc test# Command line: awk -f awksrc/^$/ { print "This is a blank line." }/[0-9]+/ { print "That is an integer." }/[A-Za-z]+/ { print "This is a string." }
Review week five lab assignment• Perl Hash table is an unordered set of scalars,
accessed by some string value that is associated with each scalar.
%colormap=(“12” => “gray”,“19” => “black”,“30” => “red”,);
%colormap = (“12”, “gray”, “19”, “black”, “30”, “red”);
%members = (John => "father", Paul => "son", Marie => "daughter");
Review week five lab assignmentDefine Comma – arrow: The comma-arrow (=>) operator is used to
initialize the %members hash variable in the previous slide lines of code. The left side of the comma-arrow operator is expected to be a simple string and therefore it is not necessary to be quoted.
Review week five lab assignment
BLACK RED GRAY
YELLOW BLUE WHITE
GREEN AMBER GOLD PINK
11 12 13
21 22 23
31 343332
Hash Table
Week six expected outcomesUpon successful completion of this module, the
student will be able to:• Create makefile scripts for software programs. • Use pattern rules in make files. • Create an effective PowerPoint presentation. • Create make files with multiple targets. • Install software packages on a server.
Next lab assignmentInstalling software under UNIX is not always
straightforward and easy. System administrators must be familiar with the layout of the file system. During a software installation, the possibility exists that the system could panic and/or have a hard disk failure.
Next lab assignmentInstallation Software Package Methods
Package manager- What are the tasks of a package manager?
- The version of UNIX dictates which package manager will be used.
- Many Linux versions utilize the Debian Package Manager.
Manual - The utilization of makefiles or shell scripts to
automate the install as much as possible. - On occasion, the installation of software is done by sending the source code to the site.
- What steps are required to install a new software version?
- How is a “configure” script utilized?
Next Lab Assignmentshell
Kernel
Hardware
Assembler
Firmware
Break-out problems• touch command• dot command• dot dot command• What function does the makefile provide a project? • What are the two parts of a dependency rule?• What language is used for writing makefile rules?• What two methods are used for installing software
packages?• What is a regular expression• American National Standard Institute (ANSI)
Upcoming deadlines• Lab Assignment 6-2 is due October 25, 2009.• Lab Assignment 6-1 is due November 1, 2009.• Lab Assignment 7-1 (midterm) has to be
completed by October 25, 2009. Midterm exam will be administered from October 19 through 24.Midterm outline will be posted on the Bulletin Board by October 4, 2009.
Questions and answers
• Questions• Comments• Concerns
• Are there questions regarding the mid-term outline?
• After class I will help students with their scripts.