Week Two Agenda

Week Two AgendaAnnouncements

Link of the weekUse of Virtual MachineReview week one lab assignmentThis week’s expected outcomesNext lab assignments AnnouncementsBreak Out ProblemsUpcoming DeadlinesLab assistance, questions and chat time

AnnouncementsClass participation

Class participation is an essential element in this class. Many times a student’s final grade borderlines the next highest letter grade. The course instructor has the authority to assign or not to assign the next highest final grade when the score is within .5 and 1 points of the next highest letter grade. Convince me professionally, that you want an “A” in this course.

Link of the week• The link below lists most all operating systems that are

available.• http://dmoz.org/Computers/Software/Operating_Systems• The link below has tabs for books, posters, software, and tools• http://www.javvin.com/unix-like-poster.html• Definition of Operating System (OS)• Common operating systems discussed in this class will be:

UNIX, Linux, and HP-UX• Basic tasks performed by an operating system

– Control and allocate memory for processes– Prioritize system requests for the CPU– Control input and output transmissions to and from devices– Facilitate networking and support file system management

Link of the weekServices Operating System (OS) perform

– Process management – Memory management

OS coordinates various types of memory – File systems– Networking – Graphical user interface (GUI) and command line– Device drivers– Security

• Internal management• External management

Use of the Virtual MachineKnoppix features• Use the sftp command to move a file from

Knoppix software to the cs.franklin.edu (Einstein) machine using VMware software

Open two Konqueror windowsEnter the ftp protocol sftp://[email protected]/export/home/dandrear

in one screenOpen a Konsole screen and create a file

to transfer to the cs.franklin.edu machine.

Review week one lab assignmentBasic vi editor commands.

vi test_file.txt^ (place cursor on beginning of line)$ (place cursor at end of line)o (insert text - alpha character)cw (change an entire word in a file)Esc key (exit insert mode):wq! (save text entered in file):q! (quit without saving changes)

Review week one lab assignmentLess command

q (terminates pagination)Enter or Return key (advance one line)Space bar (refresh entire screen)

Location of weekly Power Point presentations:http://cs.franklin.edu/~dandrear/itec400/Winter_2011_

Franklin_Live_Presentations/

File format: Week_Two_2_ppt.ppt Week_Two_2.pptx

Review week one lab assignmentif [ ]

thenAction statements

fi

while [ ]do

Action statementsdone

for file_name in *do

Action statementsdone

Review week one lab assignment#!/bin/kshNUMBER=$1# One argument must be provided, otherwise don’t executeif [ …]

then…… Action statement(s)

exit …..# The value of the command line argument can’t# be less than or equal to zero.

elif [ …]then

……Action statement(s)exit …..

fi

Review week one lab assignment# Integer value must be greater than zerowhile [ ……… -gt 0 ]

do printf $variable# If the value of the argument is greater than one, insert a comma

after the integer if [ ………… -gt 1 ] then printf ", " fi# Decrease the value of NUMBER by one with each iteration NUMBER=$(($.................. - 1))

doneprintf

Review week one lab assignment

ERROR1="error: can only use 0 or 1 arguments.\nusage: maxlines.sh [directory]"ERROR2="error: argument must be a directory.\nusage:

maxlines.sh [directory]\n"# Verify that more than one command line argument

doesn't exist.if [[ $# -gt 1 ]] then printf "$ERRORX" exit 1 fi# Default variable settingDIR="."

Review week one lab assignment# Case #2.# The number of arguments on the command line equals one.if [[ $X -eq 1 ]]

then # Is the command line argument a directory?

if [[ -X $1 ]] then # Assign the command line argument to the variable, DIR="$X" else printf "$ERRORX" exit 1 fi fi

Review week one lab assignment# All cases are processed with the following code.# Change directory to the indicated variable content.cd $XXX# Assign file name with highest number of new lines to

the variable FILE.FILE=$(wc –X `ls` 2>/dev/XXXX | sort –X X | tail –X

X | head –X X)# Print statement for all cases.printf "File `echo $FILE | awk '{print $X}'` has the

maximum lines with `echo $XXXX| awk '{print $X}'` lines.\n"

exit 0

Review week one lab assignmentCase #1: ./printnum.sh <numeric value>/~dandrear/itec400/homework

Case #1: ./maxlines.sh or ./maxlines.sh ./~dandrear/itec400/homework

printnum.shmaxlines.sh

Case #2: ./maxlines.sh /bincat

chmodcp, … etc

Review week one lab assignmentman (uses the “less” command for pagination)ls –lpsls -acut –c 1-7wc -l$#dateexit 0exit 1NUMBER=$2echo $NUMBERless

Review week one lab assignmentcp file1 file2mv file1 file2rm file_1 rmdir dir_1clearheadtailwhomyArray[1]=$1moreps –ef

Review week one lab assignmentgrepfindlsmkdircd $1$1, $2, $3cat <file name>chmod <permission> <file name>

Review week one lab assignment

sleep <number of seconds>diff <file name> <file name>cd <directory>sort <file name>umaskumask -Swhowho am i

Weeks 2 and 3 expected outcomes

Upon successful completion of this module, the student will be able to:

• Create scripts using shell variables and program control flow.

• Use man page system and find script tools. • Use redirection and pipes to combine scripts and

executables.

Next lab assignmentIn a Unix environment, the commands you

enter are executed by a program called the "shell". The user must select a command shell to communicate with UNIX. Examples are Korn, Bourne, and C Shell.

One of the things that makes the UNIX operating system so flexible is its layered design. At the core is the hardware. The hardware is surrounded by system software that most users never interact with called the kernel . The kernel is surrounded by programs (often called utilities) such as cat, date, and diff commands that perform specific tasks. A shell program communicates with these utilities and the kernel with text type information.

Next lab assignment

A shell program enables a user to interact with computer resources, such as programs, files, directories, and devices. Shells allow users to interact on a system interactively as a command interpreter. When acting as command interpreter, the shell is the interface between the user and the system in a real time environment.

Next lab assignmentMost shells are used as a programming

language. Users can combine command sequences to create new programs. These programs are known as shell scripts. Shell scripts automate the use of the shell as a command interpreter.

The first line of any script must begin with #!, followed by the name of the interpreter.Examples: #!/bin/ksh

#!/bin/bash#!/usr/bin/perl

Demonstrate: cat /etc/shellsecho $SHELL

Next lab assignmentConcentric Circle Relationship

KERNELHARDWARE

Shell

Utilities

Kernel

csh

sort

ps

vi

Next lab assignmentdrwxrwxrwx permissions (directory)-rwxrwxrwx permissions (file)lrwxrwxrwx permissions (symbolic link)-rwx------ 2 dandrear faculty (hard link)crw------- 1 root root 14, 4 Jun 24 2004 audiobrw-rw---- 1 root disk 29, 0 Jun 24 2004 aztcdThe exit command has a return value.

0 indicates normal exit1 indicates failed exit

The return value of a command can be used with conditional or iteration commands.

Next lab assignmentExit command

Allows you to exit from a program, shell or log you out of a Unix network.The exit command may be used to terminate a script, just as in a C program. It can also return a value, which is available to the script's parent process.Every command returns an exit status (sometimes referred to as a return status ).

The exit command values range is from 0-255.0 indicates normal exit1 indicates failed exit

Next lab assignmentPipe Command

Users can connect the standard output of one command into the standard input of another command by using the pipeline operator (|).

Demonstrate general commands:ps -efps –ef | wc –lps –ef | awk ‘{print $2}’ps –ef | grep dandrearls –l | cut –c1-3who –b (time of last system boot)who –d (print dead processes)who –r (print current run level)

.

Next lab assignmentFile Descriptor

A process associates a number with each file it has open. 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: File descriptor 0 is open for reading.Standard output: File descriptor 1 is open for writing.Standard error: File descriptor 2 is open

reading.

Next lab assignmentManual (man) Command

Linux command documentation is known as “man”. Each page is a self-contained document.

The Manual sections are split into eight numbered sections:

1 General commands.2 System calls3 C library functions4 Special files (usually devices, those found in

/dev) and drivers.5 File formats and conventions6 Games and screensavers7 Miscellaneous8 System administration commands and

daemons

Next lab assignmentGrep Command

The grep command searches the named input file(s) forlines containing a given pattern. Normally,each line found is reported to standard output.Demonstrate:

grep text ~dandrear/Winter08_solutions/foobargrep pattern foobar_1grep pattern *

Next lab assignmentFind Command

The find command lists all pathnames that are in each of the given directories.Demonstrate:

find / -type d –printfind ~dandrear –type d -printfind . –printfind / -name foobar

Next lab assignmentRedirections

Many UNIX commands take text-like input and/or produce text-like output. It's sometimes useful to be able to control where the input comes from and output goes (via redirection), or even pass the output from one command to another's input (via pipes).

Next lab assignmentRedirection (cont)

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/Summer2010_solutions/test.txtAppend the standard output of a command to a file.

cat foobar_2 >> foobar_1

Next lab assignmentCoding and Testing Process

Code one small script function at a time.Test that function before adding more code to

the script.Program coding is an iterative process

(code,test,code,test,code,test, …).

Break Out Problems1. ps | wc –l2. who | awk ‘{print $1}‘ | sort –u | wc –l3. ps –ef | awk ‘{print $1}’ | sort –u | wc –l4. sort –r names.txt5. ps –ef | awk ‘{print $9, $1}’ 6. find /bin -name gzip7. find /etc -name motd8. > newfile9. rm newfile10.date | cut –c12-1911.cp test_data.txt ~dandrea/temp12.mv test_data.txt ~dandrear/temp13.printf $NUMBER

Upcoming Deadlines• Lab Assignment 2-1, Simple Shell Scripting,

due May 15, 2011.• Lab Assignment 3-1, Advanced Scripting, due

May 22, 2011.• Read Chapters 1 and 2 in Essential System

Administration text.• Read Module Two listed under the course Web

site• Did everyone receive a Shell Quick Reference

document and script logic for Lab Assignment 2-1?

Lab assistance, questions and answers• Questions• Comments• Concerns

• After class I will help students with their scripts.