2. Week Three Agenda Link of the Week Review Week Two Information
Administrative Issues
Link of the Week
Review Week Two Information
This Week’s Expected Outcomes
Next Lab Assignment
Break-Out Problems
Upcoming Deadlines
Lab Assistance, Questions, and Answers

3. Administrative Issues
This is the last week for identifying a proctor. Many students have already selected their proctor for their midterm exam. This same proctor list will be utilized for the final exam unless a change request is ed to the Student Learning Center and me two weeks prior to the final exam date.

4. Link of the Week
APA Style writing guidelines will be utilized for all lab assignment reports .
APA Style
APA Style Writing Workshop
Grading will focus mainly on capitalization, punctuation, grammar, and citation.

5. Link of the Week Linux Forums Web Site
This web site allows individuals to post questions about Fedora Linux and Redhat Linux. The people that maintain this site are knowledgeable users of these operating systems. If your experiencing problems with commands or just want to learn more about these systems, you can find this type of information at this site.

6. Review Week Two Information
Caveat:
Knoppix software was designed to be used as a Live CD because of specific features that make it’s performance and stability very suitable. It has been noted in several articles that Knoppix works best from a Live CD. Knoppix enthusiasts have attempted to install this software on a hard disk and encountered problems in the process. These problems are most pronounced when installing updates and new software.

7. Review Week Two Information
Users can connect the standard output of one command into the standard input of another command by using the pipeline operator (|).
Demonstrate
ps -ef
ps –ef | wc –l
ps –ef | awk ‘{print $2}’
ps –ef | grep dandrear
ls –l | cut –c1-3
who | sort > test_file.txt
The output of the who command is piped to the
sort function and written in ascending order in the
test_file.txt file. The “who” and “sort” commands execute in parallel.

8. Review Week Two Information
Commands
who –b (time of last system boot)
who –d (print dead processes)
who –r (print current run level)
List directory entries using the ls –l | less command
drwxrwxrwx permissions (directory)
-rwxrwxrwx permissions (file)
lrwxrwxrwx permissions (Symbolic link)
-rwxrwxrwx 2 dandrear (Hardlink)

9. Week Two Information
A process associates a number with each file that it has opened. This number is called a file descriptor. When you log in, your first process has the following three open files connected to your terminal.
Standard Input (stdin) : File descriptor 0 is open for reading.
/dev/stdin
Standard Output (stdout): File descriptor 1 is open for writing.
/dev/stdout
Standard Error (stderr): File descriptor 2 is open reading.
/dev/stderr
Demonstrate
ls –a > /tmp/output 2>&1
> is equivalent to 1>
< is equivalent to <0

10. Week Two Information

11. Review Week Two Information
A file descriptor is generally an index for an entry in a kernel-resident data structure that contains information on all open files. Each process on the system has its own file descriptor table. A user application passes the abstract key to the kernel through a system call, and the kernel accesses the file for the application. A data structure is a specific way of storing and organizing data in a computer so that it can be accessed with high efficiently. Data structures can be used as a single place for storing unrelated information.

12. Review Week Two Information

13. Review Week Two Information
The grep command searches the named input file(s) for
lines containing a given pattern. Each line found is reported to standard output.
Demonstrate:
grep UNIX foobar_3
grep ‘^UNIX’ foobar_3
grep ‘UNIX$’ foobar_3
grep pattern foobar_1
grep pattern *
The find command lists all pathnames that are in each of the given directories.
find / -type d –print
find ~dandrear –type d -print
find . –print
find / -name foobar

14. Review Week Two Information
Redirection Symbols:
Redirect the standard output of a command to a file.
date > /tmp/date_saved
Redirect the standard input of a command so that it reads from a file instead of from your terminal.
cat < ~dandrear/Fall2010_Solutions/test.txt
Append the standard output of a command to a file.
cat foobar_2 >> foobar_1

15. Review Week Two Information
Korn Shell Syntax and Commands srchfile.sh $1 $2 original=$PWD cd $original cd $2 listing=`ls –l | cut –c57-80` for file_name in listing do (boundary) Action Statements done (boundary)

16. Review Week Two Information
Commands
ls –l | more
ls –l | less (count the fields/use “q” to quit)
ls -a (does not hide entries)
less
man (utilizes the less command for reading online documentation).
cat > test_file (keyboard input goes into test_file)
cat < test.txt (test_file is displayed on terminal)
cat foobar_2 >> foobar_1 (append first file to second file)

17. Review Week Two Information
Commands
> test_file
cat /etc/passwd
grep x /etc/passwd | cut –d’:’ –f1
chmod 705 *
chmod 705 test_file
grep line ~dandrear/Summer2010_Solutions/foobar_1
find ~dandrear –type d -print
myArray[1]=$1 $0

18. Review Week Two Information
Commands:
The tilde (~) symbol is used to represent the user’s current home directory (e.g. /export/home/dandrear)
The command line arguments are:
$0 $1 $2 $3 …

19. Review Week Two Information
Demonstrate /export/home/dandrear/.profile umask 077 The umask variable contains the default permissions for a file and a directory. Variables Used by Korn Shell: HOME = is set to the full path name of your login directory (/export/home/dandrear) PATH = contains the command search path. It is set to a series of path names separated by colons (:).

20. Review Week Two Information
Variables Used by Korn Shell
SHELL = This entry may be set by the system administrator to the path name of a shell interpreter other than the standard bash.
TERM = specifies what terminal you are using.
TMOUT = variable contains the integer attribute. If you set the value greater than zero, ksh terminates if you do not enter a command within the prescribed number of seconds after ksh issues the PS1 prompt.
MAIL = Name of your Mail files
EDITOR = Pathname for your editor

21. Review Week Two Information
Man page
Man formats and displays the on-line manual pages. If you specify section, man only looks at that section of the manual. Name is normally the name of the manual page, which is typically the name of a command, function, or file. However, if name contains a slash (/) then man interprets it as a file specification.
Each section has an introduction which can be obtained with, e.g., "man 2 intro“ or “man ./foobar_1”.
If MANPATH is set, man uses it as the path to search for manual page files.

22. Review Week Two Information
Man Page Sections
1 Commands
2 System calls
3 C library routines
4 Devices and networks
5 File formats
6 Games and demos
7 Miscellaneous
8 System administration.

23. Review Week Two Information
Types of File and Directory Access:
Access File Meaning Directory Meaning
r View file contents Search directory contents
w Alter file contents Alter directory contents
x Run executable file Make your current directory
-rwx Owner 700
----rwx Group 070
rwx Other

24. Review Week Two Information
Shell and Programs Access:
To run a shell script, you will need read (r) and execute (x) access. The read access mode is a binary 4. The execute access mode is a binary 1.
To run a binary executable program, you will need execute (x) access. The execute access mode is a binary 1.

25. Week’s 2 & 3 Expected Outcomes
Upon successful completion of this module, the student will be able to:
Create scripts using shell/Perl variables and program control flow.
Use redirection and pipes to combine scripts and executables.
Use man page system and find script tools.
Discuss Perl Language

26. Next Lab Assignment Introduction to Perl:
Perl - Practical Extraction and Report Language
Originally developed by Larry Wall, a linguist.
Perl is 21 years old and Perl 5 is 14 years old.
Perl is a simple language
- Compiles and executes like a shell script or a batch file
- Perl doesn’t impose special growth limitations on arrays and data strings
- Perl is a composite of C, AWK, and Basic
- Originally developed to process text and automating tasks.

27. Next Lab Assignment Perl’s range of flexibility
- System administration
- Web development
- Network programming
- GUI development
Major features
- Procedural Programming
Sequence or unstructured statements
Includes routines, subroutines, methods, or functions
- Object Oriented Programming
Module uses “objects” and their interactions to design applications and computer programs.

28. Next Lab Assignment Major features (continued)
- Powerful built-in support for text
processing
- Large collection of third-party
modules.

29. Next Lab Assignment
The Advanced Scripting lab assignment requires two shell scripts to be written.
srch.sh
srchfile.sh
Demonstrate
Execution of srch.sh and srchfile.sh
Case #1: ./srch.sh <pattern> <file name / directory name>
The srch.sh script will call the srchfile.sh script to perform a specific task. The srchfile.sh searches for a file with a pattern and outputs the matching information to standard output. After all directory entries have been read, control is returned to the main script, srch.sh.

30. Break Out Problems
1. 2. $ARGV[0] 3. filter 4. unless 5. $NUMBER 6. exit 1 7. $ARGV[1] 8. % (%directory) 9. $ ($quote) 11. diff 12. tr “[a-z]” “[A-Z]” < filein > fileout

31. Next Lab Assignment Read your Programming Perl text book.
Chapter One (1)
Chapter Two (2)
Review Chapter 32: Standard Modules
Review Chapter 33: Diagnostic Output Messages
Read Module Two listed under the course Web site.

32. Upcoming Deadlines
Lab Assignment 1-1, Obtain a Proctor for Exams, due September 19, 2010.
Lab Assignment 2-1, Simple Shell Scripting, due September 26, 2010.
Lab Assignment 3-1, Advanced Scripting, due October 3, 2010.
Lab Assignment 4-1, Simple Perl Exercise, due October 10, 2010.

33. Lab Assistance, Questions and Answers
Comments
Concerns
After class I will help students with their scripts.