Week Six Agenda

2. Week Six Agenda • Announcements • Link of the week • Review week four lab assignment • This week’s expected outcomes • Next lab assignment • Break-out problems • Upcoming deadlines • Lab assistance, questions and answers

3. Link of the week http://en.wikipedia.org/wiki/Computer_security This article describes how security can be achieved through design and engineering http://en.wikipedia.org/wiki/Secure_Computing Firewalls, Safe Word authentication products, Internet filtering products like Smart Filter, Bess, and Webwasher

4. Link of the week • Define: Trusted System • Define: Trusted Computing • Where are trusted systems utilized? • How are trusted systems utilized?

5. Review week five lab assignment

6. Review week five lab assignment • Define a makefile • 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 • Demonstrate makefile script under ~dandrear/temp (Einstein)

7. Review week five lab assignment What is the makefile utility used for? Other 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 file What 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.

8. Review week five lab assignment Target : Dependencies (prerequisites) <tab> Rule prog: a.o b.o c.o g++ a.o b.o c.o -ly –o prog a.o: prog.h a.c g++ –c prog.h a.c b.o: prog.h b.c g++ –c prog.h b.c c.o: c.c g++ –c c.c c.c: c.y yacc c.y mv y.tab.c c.c

9. Review week five lab assignment

10. Review week five lab assignment

11. Review week five lab assignment Key Points About Makefile • Makefile recompiles all source files for a project. • Makefile only recompiles files that have been changed. • Bottom up control flow • Rules may be complex shell commands

12. Review week five lab assignment Key Points About Perl • Dynamic typing • Dynamic allocation of memory for arrays and hash tables • Both procedural and object oriented programming capabilities • Rich third party software and use of modules

13. 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.

14. 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”);

15. Review week five lab assignment

16. Week six expected outcomes Upon 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.

17. Next lab assignment Installing 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.

18. Next lab assignment Installation 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. - Many times 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?

19. Next lab assignment Assignment number: 5-1 test scenarios Command line: ./listdir.pl Command line: ./listdir -l Command line: ./listdir -l -d <directory> Command line: ./listdir -d <directory>

20. Next Lab Assignment $dirLoc="."; # Default to current working directory for ($a=0;$a<=$#ARGV;$a++) { # Verify that the option is a “d” if ($ARGV[$a] eq “XXXX") { $dir=1; if (-d $ARGV[$XXXX]) { # Assign the second argument (directory) to a variable $dirLoc=$ARGV[$XXXX]; } else { $errorDir=1; } # Verify that the option is a “l” } elsif ($ARGV[$a] eq “XXXX") { $long=1; } }

21. Next Lab Assignment # Open the directory that was assigned to # $dirLoc variable opendir(XXXX, "$dirLoc") || die "Cannot open directory.\n"; # Assign all file names to array @unfiles=readdir(XXXX); $z=1; # Sort file names in ascending order @files = sort { uc($a) cmp uc($b) } @XXXX;

22. Next Lab Assignment foreach $file (@files) { if (-f "$dirLoc/$file") { if ($long) { if ($z==1) { printf("%-30s%10s%10s%10s\n","File Name","Size","User","Group"); } ($dev, $ino, $mode, $nlink, $uid, $gid, $rdev, $size, $atime, $mtime, $ctime, $blksize, $blocks) = stat "$dirLoc/$file"; $group=getgrgid($gid); $user=getpwuid($uid); printf(“%30s%10.f%10s%10s\n”, $file,$size,$user, $group); printf("%30s%10.f%10s%10s\n", $file,$siz e,$user,$group); } elsif ($nolong) { $printFiles.="$XXXX, "; } else {

23. Next Lab Assignment if ($z==1) { printf("File Name\n"); } print "$file\n"; } $z++; } }

24. Next Lab Assignment if ($nolong) { chop($printFiles); print "$printFiles\n"; } closedir DIR;

25. Next Lab Assignment shell Assembler Kernel Firmware Hardware

26. Next lab assignment • Demonstrate: Execute Fall08_solutions/listdir.pl script

27. 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)

28. Upcoming deadlines • Mid-Term review (True/False, Multiple choice) • Mid-term exam dates 2/19/09. • makefile Exercise, 6-1 is due 2/22/09. Create the specified files referred to in Lab Assignment 6-1. • Programming Assignment 1, 5-1 is due 10/28/08. • Installation Exercise, 8-1 is due 11/4/08.

29. Questions and answers • Questions • Comments • Concerns • Are there questions regarding the mid-term outline? • After class I will help students with their scripts.