Transcript Appendix A-Linux_cs3

Appendix A
Introduction to
Using Linux
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Objectives
Linux introduction
Commands-Line Interface
Files and Directories
Basic Commands
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The password Command
The man Command
The ls Command
The cp Command
The mv Command
The rm Command
The cd Command
The mkdir Command
I/O Redirection and Pipe Operators
Shell Variables
Text Editing
File Access Permissions
Script Files
Searching Data in Files
Evaluating Expressions
Connecting to a Remote Linux Server, cs3
Dr. Garrido and el al Textbook
©2012 Jones & Bartlett Learning, LLC
www.jblearning.com
Connecting to a Remote
Linux Server, cs3
• Please refer to Appendix A in the Course
Textbook or follow the steps from the link
below.
• Download SSH Secure Shell Client
• Go to http://uits.kennesaw.edu/students
• Go to Software Downloads
• After downloading, execute the install program
SSH Secure Shell Client (icon will be on your desk top)
Click on the SSH Secure Shell Client
Download SSH Secure Shell Client
• Download the SSH (Secure Shell File Transfer
(SFTP));
– from KSU UITS / Software Downloads.
http://uits.kennesaw.edu/students (SSH consist of
SSH Secure Shell Client and SSH File Transfer),
• Note: for this course, you need to use SSH
Secure Shell Client to login to CS3 server.
• Default: SSH Secure Shell Client icon
will be install on your desktop Windows.
• Click on Profiles folder on
the tool bar
• Select Add Profiles
• Give a name: cs3
• Edit Profiles cs3
• Host name:
cs3.kennesaw.edu
• User name:
• your KSU netid
• Ok
• Go to Profiles
• Select cs3
• Enter Password:
• Temp password: new123
• Login to cs3 server, then
• Change password: $passwd
Login to Linux
server
cs3
The CS3 Server
• A Computer Science Department server
• All assignments are to be developed on the
CS3 server
• Access to CS3 is via a command-level interface
using a ‘terminal’ utility, such as SSH on
Windows
Connecting to CS3 Server
• Make sure you are connected to Internet
• Start SSH (Secure Shell Client) to connect to a
remote Unix server
• Type cs3.kennesaw.edu
• Logon to Linux on the CS3 server
• Start using the appropriate Linux shell
Window for SSH Shell Client
Logged in to cs3 Linux server
Running Simulation Models on CS3
Use the 'mkdir' command to make a new directory under
the current directory, then change to the new directory
with the 'cd' command.
$ mkdir myos
$ cd myos
• Copy two files from the /home/jgarrido/psim3
directory to your working directory:
– the corresponding simulation model (batch.cpp)
– the psim3c script file
$ cp /home/jgarrido/psim3/batch.cpp myos
$ cp /home/jgarrido/psim3/psim3c myos
Steps to Run a Simulation Model on
cs3 (Cont.)
• Change to the new directory: $ cd myos
• Compile and link the simulation model:
$ ./psim3c batch.cpp
• Run the model (output on the screen):
$ ./batch.cpp //FN.ccp
$ ls –lt //to see which file is ready
to be exeucted. The list
//should show files and executed file (in different color), that the one you need to Run
$./psim3
$ a.out
// follow the file name
• Run the model, redirect the output to a file
$ ./a.out |tee res1.txt
• View the output file
$ more res1.txt
Steps to Run a Simulation Model on
cs3 (Cont.)
• Run the program again to change one or more
parameters in the model
• Compile and link again (if necessary)
• Run the program again
• Get the results in another file
• After the third simulation run, exit Unix.
• Use SSH File Transfer from your PC to get the
output files
‘ls’ Command
• List files and subdirectories in current
directory or specified directory
$ ls
• The long listing is produced with the -l option:
$ ls -l
$ ls -lt | more
To edit a text file
• To edit a text file (C++ source file), use the
“nano” editor. For example, to edit
“batch.cpp” type the following command:
• $nano batch.cpp
‘man’ Command
• To get a short online manual or
documentation on the specified command
$ man ls
(help with ‘ls’)
$ man cd
(help with ‘cd’)
The space key shows the next page
Make and Change Directory
• To make a new directory under your current
directory:
$ mkdir mydir
• To change to a directory:
$ cd mydir
(change to mydir)
or
$ cd myos
(change to myos)
Directories
• The system root directory is denoted as a slash (/)
• An absolute path denotes the position of a file in
the file structure
/home/jgarrido/psim3/batch.cpp
• The current working directory is denoted as dot
(.), The parent of the current directory as dotdot
(..)
Show Current Working
• To display the current working directory:
$ pwd
• To return to your home directory:
$ cd
The ‘script’ Command
• Open a new record session (log session) to a
text file:
$ script mysession.txt
• To terminate the session, type the ‘exit’
command
Introduction to Linux
• Linux is a multiuser, multitasking operating
system that is a variant of Unix and preforms
many of the same functions.
• Linux is to purchase a Linux distribution, an
organized bundle that includes the kernel
(core of the operating system) and a large set
of utility programs with installation utility.
Dr. Garrido and el al Textbook
©2012 Jones & Bartlett Learning, LLC
www.jblearning.com
Introduction to Linux
• A user interacts with Linux using one of
several available interface that are grouped
into two categories
– A text-based command line interface
– A graphical user interface (GUI)
• Linux has several graphical user interface
available, such as GNU Network Object Model
Environment (GNOME) and the K Desktop
Environment (KDE)
Dr. Garrido and el al Textbook
©2012 Jones & Bartlett Learning, LLC
www.jblearning.com
What is Linux?
Linux is, in simplest terms, an operating system.
It is the software on a computer that enables applications
and the computer operator to access the devices on the
computer to perform desired functions. Linux is very
similar to other operating systems, such as Windows
and OS X.
Linux operating system represented a $25 billion
ecosystem in 2008. Since its inception in 1991 and in
2011 earn up to 49 billion.
Linux has grown to become a force in computing,
powering everything from the New York Stock Exchange
to mobile phones to supercomputers to consumer
devices.
Linux Overview
 Linux is developed collaboratively, meaning no one
company is solely responsible for its development or
ongoing support.
 Companies participating in the Linux economy share
research and development costs with their partners
and competitors.
 This spreading of development amongst individuals
and companies has resulted in a large and efficient
ecosystem and unheralded software innovation.
 Over 1,000 developers, from at least 100 different
companies, contribute to every kernel release.
 In the past two years alone, over 3,200 developers from 200 companies
have contributed to the kernel--which is just one small piece of a Linux
distribution.
Where is Linux
Linux Uses in:
Desktop, Laptops, Phones, small devices,
Mainframes, supercomputers Browser like
Firefox, servers, Sony TV, Reader, Digital
Recording devices.
Many of the popular Web 2.0 services on the
Internet, such as Twitter, Linked In, YouTube, and
Google all rely on Linux as their operating system.
As new web services arrive in the future, Linux
will increasingly be the platform that drives these
new technologies.
On August 25, 1991, a Finn computer science
student named Linus Torvalds made the following
announcement to the Usenet group
comp.os.minux
Torvalds built the core of the Linux operating
system, known as the kernel.
A kernel alone does not make an operating system,
but Stallman's GNU tools were from a project to
create an operating system
Torvalds' matching of GNU tools with the Linux
kernel marked the beginning of the Linux
operating system as it is known today.
Linux Began
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The term runlevel refers to a mode of operation in one of the
computer operating systems that implement Unix System V-style
initialization.
Conventionally, seven (7) runlevels exist, numbered from zero to six;
though up to ten, from zero to nine, may be used.
S is sometimes used as a synonym for one of the levels. Only one
"runlevel" is executed on bootup - run levels are not executed
sequentially, i.e. either runlevel 2 OR 3 OR 4 is executed, not 2
then 3 then 4.
"Runlevel" defines the state of the machine after boot. Different
runlevels are typically assigned to:
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single-user mode
multi-user mode without network services started
multi-user mode with network services started
system shutdown
system reboot
Run Levels
Weblink
Kernel
All operating systems have kernels, built around
the architectural metaphor that there must be
a central set of instructions to direct device
hardware, surrounded by various modular
layers of functionality. The Linux kernel is
unique and flexible because it is also modular
in nature.
Modularity is desirable because it allows
developers to shed parts of the kernel they
don't need to use. Typically a smaller kernel is a
faster kernel, because it isn't running processes
it does not need.
Linux Environments
The windows, menus, and dialog boxes most people
think of as part of the operating system are actually
separate layers, known as the windowing system and
the desktop environment.
These layers provide the human-oriented graphical user
interface (GUI) that enables users to easily work with
applications in the operating system and third-party
applications to be installed on the operating system.
There are tools and code libraries available that let
application developers to more readily work with
these environments