Transcript Week_Two_2x

Week Two Agenda
•Announcements
•Link of the week
•Use of Virtual Machine
•Review week one lab assignment
•This week’s expected outcomes
•Next lab assignments
•Announcements
•Break Out Problems
•Upcoming Deadlines
•Lab assistance, questions and chat time
Announcements
Class participation
Class participation is an essential element in
this class. Many times a student’s final grade
borderlines the next highest grade. The score
closeness could be .5 to 1. It is the instructors
discretion based on the students performance
in class, as to whether the next highest grade is
given.
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 are:
UNIX, Linux, HP-UX
• Basic tasks performed by an operating system
– Control and allocate memory
– Prioritize system requests
– Control input and output devices
– Facilitate networking and management file systems
Link of the week
Services 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 Machine
Knoppix features
• Demonstrate how to ftp a file from Knoppix
software to the cs.franklin.edu (Einstein)
machine using VMware software
Open two Konqueror windows
Enter the ftp protocol
sftp://[email protected]/export/home/dandrear
in one screen
Open a Konsole screen and create a file to
transfer to the cs.franklin.edu machine.
Review week one lab assignment
Basic 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 assignment
less command
q
Enter or Return key
Space bar
(terminates pagination)
(advance one line)
(refresh full screen)
Location of weekly Power Point presentations:
http://cs.franklin.edu/~dandrear/itec400/Fall_Franklin_Live_Pres
entations
File format: Week_Two_2_ppt.ppt
Week_Two_2.pptx
Review week one lab assignment
if [ ]
then
Action statements
fi
while [ ]
do
Action statements
done
for file_name in *
do
Action statements
done
Review week one lab assignment
Reserved words
The following reserved words for the Bourne
shell are recognized only when they appear
without quotation marks as the first word of a
command.
for
esac
fi
while
do
if
elif
until
done
then
else
{}
case
()
Review week one lab assignment
NUMBER=$1
# One argument must be provided, otherwise don’t execute
if [ …]
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 zero
while [ ……… -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))
done
printf
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
DIR="."
Review week one lab assignment
# Case #2 and 3.
# The number of arguments on the command line equals one.
if [[ $X -eq 1 ]]
then
# Is the directory entry 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 assignment
Case #1: ./printnum.sh <numeric value>
/~dandrear/itec400/homework
Case #1: ./maxlines.sh
/~dandrear/itec400/homework
printnum.sh
maxlines.sh
Case #2: ./maxlines.sh <directory value>
cat
chmod
cp
Review week one lab assignment
man (uses the “less” command for pagination)
ls –l
ps
ls -a
cut –c 1-7
wc -l
$#
date
exit 0
exit 1
NUMBER=$2
Review week one lab assignment
cp file1 file2
mv file1 file2
rm file_1
rmdir dir_1
clear
head
tail
who
myArray[1]=$1
more
ps –ef
Review week one lab assignment
grep
find
ls
mkdir
cd $1
$1, $2, $3
cat <file name>
chmod <permission> <file name>
echo $NUMBER
less
Review week one lab assignment
sleep <number of seconds>
diff <file name> <file name>
cd <directory>
sort <file name>
umask
umask -S
who
who 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 assignment
In a Unix environment, the commands you enter
are executed by a program called the "shell". The user
must select a command shell used to communicate
with UNIX. Examples are Korn, Bourne, and C
Shell.
One of the things that makes the UNIX system so
flexible is its layered design. At the core of these
layers is the hardware. The hardware is surrounded
by system software that most users never interact
withThis system software is called the kernel. The
kernel is surrounded by programs (often called
utilities) such as cat, date, and diff, that perform
specific tasks. The shell program provides easy
access to utilities and the kernel for the user.
Next lab assignment
A shell via the kernel allows user to
interact with resources such as programs, files,
directories, and devices. An interactive shell
acts as a command interpreter.
Next lab assignment
Most shell statements can be 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/shells
echo $SHELL
Next lab assignment
Concentric Circle Relationship
Shell
Utilities
ps
Kernel
vi
sort
KERNEL
HARDWARE
csh
Next lab assignment
drwxrwxrwx permissions
(directory)
-rwxrwxrwx permissions
(file)
lrwxrwxrwx permissions
(symbolic link)
-rwx------ 2 dandrear faculty (hard link)
exit
Each command has a return value.
0 indicates normal exit
1 indicates failed exit
The return value of a command can be used with
conditional or iteration commands.
Next lab assignment
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 –b (time of last system boot)
who –d (print dead processes)
who –r
(print current run level)
.
Next lab assignment
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: 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 assignment
Linux Manual 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 calls
3 C library functions
4 Special files (usually devices, those found in
/dev) and drivers.
5 File formats and conventions
6 Games and screensavers
7 Miscellaneous
8 System administration commands and daemons
Next lab assignment
The grep command searches the named input
file(s) for
lines containing a given pattern. Normally,
each line found is reported to standard output.
Demonstrate:
~dandrear/Fall2010_Solutions/foobar_1
grep pattern foobar_1
grep pattern *
Next lab assignment
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
Next lab assignment
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
Next lab assignment
The coding 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 Problems
1. ps | wc –l
2. who | awk ‘{print $1}‘ | sort –u | wc –l
3. ps –ef | awk ‘{print $1}’ | sort –u | wc –l
4. sort –r names.txt
5. ps –ef | awk ‘{print $9, $1}’
6. find /bin -name gzip
7. find /etc -name motd
8. > newfile
9. rm newfile
10. date | cut –c12-19
11. nohup grep This ~dandrear/Fall09_Solutions/report.txt &
12. cp test_data1.txt ~dandrea/temp/test_data2.txt
13. mv test_data1.txt /tmp/test_data_one.txt
14. printf $NUMBER
Upcoming Deadlines
• Lab Assignment 2-1, Simple Shell Scripting,
due September 26, 2010.
• Lab Assignment 3-1, Advanced Scripting, due
October 3, 2010.
• Read Chapters 1 and 2 in Essential System
Administration text.
• Read Module Two listed under the course Web
site
Lab assistance, questions and answers
• Questions
• Comments
• Concerns
• After class I will help students with their
scripts.