Agenda

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Week Three Agenda

• Administrative Issues
• Link of the Week
• Review Week Two Information
• This Weeks Expected Outcomes
• Next Lab Assignment
• Break-Out Problems
• Upcoming Deadlines
• Lab Assistance, Questions, and Answers

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Link of the Week

• APA Style writing guidelines will be utilized for
  all lab assignment reports .
• APA Style Sixth Edition
• http//www.apastyle.org/learn/
• APA Style Writing Workshop
• http//www.franklin.edu/student-services/student-l
  earning-center/academic-support/workshops.html
• Grading will focus mainly on capitalization,
  punctuation, grammar, and citation.

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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.
• http//www.linuxforums.org/forum/redhat-fedora-lin
  ux-help/73994-system-commands-not-working-unless-s
  bin.html

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Review Week Two Information

• Caveat
• Knoppix software was designed to be used as a
  Live CD because of specific features that make
  its 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.

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Review Week Two Information

What is the next user interface going to
be? The textual (command line) and the visual
(graphical user) interfaces are the two most
common modalities used to support engineers in
network and system administration positions. The
command line interface is recognized as the first
generation and the graphical user interface is
considered the second generation. Currently,
research is trying to determine the next best
interface. The command line interface is known
as, under the hood method of interacting with
the operating system.
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Review Week Two Information


CLI Benefits Manipulate textual data Quick
customization of data allows engineers the
ability to change data to another
form Excellent for filtering data on
systems Commands are rich, expressive, flexible,
and powerful GUI Benefits Reduces data
overload Simple filtering and manipulation of
the data Excellent for displaying trends in data
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Review Week Two Information
Users can connect the standard output of one
command to 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 gt 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.
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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)
brw-rw---- permissions (block)
crw------- Permissions (character)
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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 St
andard 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 gt
/tmp/output 2gt1 gt is equivalent to 1gt lt
is equivalent to lt0
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Week Two Information

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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.
• What is a data structure?
• 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.

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Review Week Two Information

• A data structure is a particular way of storing
  and organizing data in a computer so that it can
  be used efficiently.
• Different kinds of data structures are suited to
  different kinds of applications, and some are
  highly specialized to specific tasks.
• Some common data structures
• array, hash table, linked list, queue, and
  stack

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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. Demonstrate find /
-type d print find dandrear type d
-print find . print find / -name foobar
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Review Week Two Information
Redirection Symbols Redirect the standard
output of a command to a file. date gt
/tmp/date_saved Redirect the standard input of
a command so that it reads from a file instead
of from your terminal. cat lt dandrear/Winter_201
3_Solutions/test.txt Append the standard output
of a command to a file. cat foobar_2 gtgt
foobar_1
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Review Week Two Information

• One Liner Expressions
• wc l
• wc l ls
• wc l ls sort bn
• wc l ls sort bn tail n 2
• wc l ls sort bn tail n 2 head n 1

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Review Week Two Information

• Korn Shell Syntax and Commands
• srchfile.sh 1 2
• originalPWD
• cd original
• cd 2
• listingls l cut c52-80
• for file_name in listing
• do (boundary)
• Action Statements (block of statements)
• done (boundary)

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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).

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Review Week Two Information

• Shell Syntax
• gt test_file
• cat /etc/passwd
• grep x /etc/passwd cut d f1
• chmod 705
• chmod 705 test_file
• grep line dandrear/Summer_2012_Solutions/foobar
  _1
• find dandrear type d -print
• myshellArray11
• 0
• touch test_file_2

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Review Week Two Information

• Commands
• The tilde () symbol is used to represent the
  users current home directory
• (e.g. /home/dandrear)
• Command line arguments example
• ./add_all 5 10 8
• Command line argument syntax.
• 0 ./add_all, 1 5, 2 10, and 3 8

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Review Week Two Information

• Demonstrate
• /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 (/home/dandrear)
• Command echo HOME
• PATH contains the command search path. It is
  set to a series of path names separated by
  colons ().
• Command echo PATH

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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.
• Command echo SHELL
• 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

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Review Week Two Information

• Manual (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.

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Review Week Two Information

• echo MANPATH
• /usr/local/man/usr/local/info/usr/share/man/op
  t/SUNWspro/man
• 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.

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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 (columns 2-4) 700
  (111000000)
• ----rwx--- Group (columns 5-7)
  070 (000111000)
• -------rwx Other (columns 8-10)
  007 (000000111)

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Review Week Two Information

• Shell and Programs Access
• To run a shell script, you will need read (r) and
  execute (x) access (r-x). 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 (--x). The execute access
  mode is a binary 1.

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Weeks 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

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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 doesnt 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.

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Next Lab Assignment

• Introduction to Perl
• The AWK utility is an interpreted programming
  language typically used as a data extraction and
  reporting tool. It is a standard feature of most
  Unix-like operating systems.
• AWK was created at Bell Labs in the 1970s, and
  its name is derived from the family names of its
  authors Alfred Aho, Peter Weinberger, and Brian
  Kernighan.
• The power, terseness, and limits of early AWK
  programs inspired Larry Wall to write Perl just
  as a new, more powerful POSIX AWK and gawk (GNU
  AWK) were being defined.

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Next Lab Assignment

• Perls 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.

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Next Lab Assignment

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

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Next Lab Assignment

• Why is awk language so important?
• Awk language is an excellent filter and report
  writer. Many UNIX utilities generate rows and
  columns of information. Awk is an excellent tool
  for processing rows and columns, and it is easier
  to use awk than other conventional programming
  languages. Perl recognized the importance of awk,
  so it was included and enhanced in Perl.

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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 ltpatterngt ltfile name /
  directory namegt
• Case 2 ./srch.sh ltpatterngt lt.gt
• 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.

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Break Out Problems

• 1. scalar_at_ARGV
• 2. ARGV0
• 3. filter
• 4. unless
• 5. NUMBER
• 6. exit 1
• 7. ARGV1
• 8. (directory)
• 9. (quote)
• 10. _at_ (_at_names)
• 11. Regular expressions
• 12. tr a-z A-Z lt foobar gt /tmp/foo

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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
  page.

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Upcoming Deadlines

• Lab Assignment 3-1, Advanced Scripting, due May
  26, 2013.
• Lab Assignment 4-1, Simple Perl Exercise, due
  June 2, 2013.

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Lab Assistance, Questions and Answers

• Questions
• Comments
• Concerns
• After class I will help students with their
  scripts.