E115 Chapters 1-4
add [program]
-Adds the program specified by program to the current environment. -Programs with a GUI component can only be used if X is enabled -The user can view a list of all available programs by typing add without a program name.
cp [-option] [old_location/]file_name new_location
-Creates a copy of the file or directory with the name specified by file_name, and places it in new_location, leaving a copy in old_location. -Multiple files and directories can be copied simultaneously, and each file_name should be separated by a space. -option: -r (recursive) - necessary to copy directories
mkdir [location/]directory_name
-Creates a new directory (folder) with the name specified by directory_name. -If no location is specified, the directory is placed in the user's current directory.
attach [locker_name]
-Creates a shortcut to the course directory specified by locker_name. -Shorter pathname: /ncsu/locker_name.
ls [-options] [location]
-Displays a list of the files and directories located in location. -If no location is specified, the contents of the current directory are shown. -options: -a (all) - displays all files, including hidden -l (long)- displays each file on separate line w/ certain details
quota
-Displays information about the AFS space of current user -Command run by default at the start of each session
more [location/]file_name
-Displays the contents of a file with the extension .txt, .html, or .css in the terminal window -Navigate the document using the spacebar
less [location/]file_name
-Displays the contents of a file with the extension .txt, .html, or .css in the terminal window -Use the ↑ and ↓ arrow keys to navigate -press "q" to return to the main screen
Linux file systems
-EXT3 - journaling extension to EXT2 - reduced time recovering file after crash -XFS - uses B- Trees (fast access)
unzip [location/]file_name.zip
-Extracts files that are located within file_name.zip so that the user can access them -Original .zip file remains in the directory and files are extracted into the same location as the .zip file
Windows file systems
-FAT/FAT32 file system - uses File Allocation Table to index files (simple yet slow) -NTFS (Windows XP) - uses binary trees (complex but fast access)
Apple OS X file systems
-HFS+ (Hierarchal File System) - uses B- Tree to index (fast access) ***different than binary trees in windows***
zip [-option] zipfile_name file_list
-Places the files in file_list in the zip file specified by zipfile_name -option: -r (recursive) - necessary to copy all directories (folders)
Dot-dot-slash "../"
-Relative pathname to the directory above your current working directory (the parent directory) -can be used in conjunction with other shortcuts
Dot-slash "./"
-Relative pathname to your current working directory -instead of typing absolute (long) pathname, use the dot. -useful when working w/ files in current working directory
Accessing AFS thru Windows / Mac / Linux
-Windows - PuTTy -Mac OS X / Linux - Terminal
Command Options
-assign more specific functions or additional actions to command -must be preceded by a dash ( - ) to work
Nodes
-can have Child Nodes under them but don't have to -If they do, they are Parent Nodes If they don't, they are Leaf Nodes
"e115" directory at NCSU
-child node to "eos.ncsu.edu" -parent node to "e" directory, which is a parent node to "e115" directory (contains info related to E115 course)
"users" directory at NCSU
-child node to "unity.ncsu.edu" -parent node to 26 directories for the alphabet (accounts sorted by first letter in Unity ID)
Volume (Scalability) on AFS
-container that keeps a set of related files and directories together on a disk partition, such as a user's home directory -users need to know what volume files are in but not physical location -allows admin to move/add volumes
Andrew File System General
-developed by Carnegie Mellon -distributes, stores, and joins files on networked computers -focuses on security and scalability (growing for more users)
File Manipulation
-interpretation of the bytes in a file, which produces or doesn't produce the desired result -viewing problems linked to wrong program that interprets the bytes in a foreign or unexpected way to the user
mv [old_location/]old_file_name [new_location/][new_file_name]
-moves file to new location -if no new name is specified, file will keep same name -if no new location, file will simply change its name
Pathnames
-specific LOCATION of each directory and file on the file tree -functions as an address
How Pathnames work
-start with the root directory ("/") -continue through each branch of the file tree to the desired location separating each directory name with a slash "/"
Linux File Names
-up to 256 characters long -no special characters. if you have to, precede with back slash "\" (some!file --> some\!file) -no forward slash "/" -no spaces, to separate words use underscore (_), like_this
E 115 Course Locker Absolute Pathname
/afs/eos.ncsu.edu/courses/e/e115
Home Directory Absolute / Relative Pathname
/afs/unity.ncsu.edu/users/m/mahernd2
Security on AFS
1. users authenticated using Kerberos, which uses a combo of time stamps and keys to est. identity and allows authentication. 2. Access Control List, which specifies access privileges users have to a directory (lidrwka)
# of Mb allotted in AFS and how to change quota
350 Mb; http://sysnews.ncsu.edu --> Quota Manager
Match the wireless standard with its range: 802.11n 802.11g 802.11b 802.11a
802.11n-230ft 802.11g-140ft 802.11b-100ft 802.11a-115ft
Match the wireless standard with its frequency: 802.11n 802.11a 802.11g 802.11b
802.11n-5Ghz 802.11a-5Ghz 802.11g-2.4Ghz 802.11b-2.4Ghz
n your own words, explain the difference between the client and server in a P2P relationship.
A client and server relationship is when two different machines act as either the client or server, one requesting information and the other distributing it, respectively. Contrastly, in a P2P relationship, one machine acts as both the client and the server through custom software that determines which role is necessary for a given task.
How to get rid of adware/spyware of Windows (most common OS hardest hit)
Ad-aware
Root directory for ASF at NCSU
"/" directory -contains all other directories and files on network
Chile node of "/" at NCSU
"afs" directory -contains directories for each of the various systems at NCSU (pams.ncsu.edu, eos.ncsu.edu, tx.ncsu.edu, and unity.ncsu.edu)
[access_list] for fs sa "rlidwka,all,none"
(r)ead- view/copy contents of files in directory (l)ook- see contents of directory (i)nsert- create/move files into directory (d)elete- delete files from directory (w)rite- make changes to files in directory loc(k)- set advisory locks in directory (a)dmin- set permissions for directory (all)- gives user all rights to directory (none)- removes user rights from the directory
What does API stand for?
Applications Programming Interface
Match the topography with its weakness: Bus Star Tree Ring
Bus-a line break will cause the network to go down completely Star-if one node fails, there is no interruption of service to the rest of the network Tree-a point of failure on a transmission line ca separate a node from the network and the rest of the network will continue to work Ring-all data travels in only on direction
cd location
Changes the current directory to the location specified by location.
pwd
Displays absolute pathname to user's current directory
How to backup files
External Hard Drive, CD's, School K: Drive, Dropbox, Internet Storage.
If you were to reboot a computer, the memory stored in RAM would still be present upon turning the computer back on. True/False
False
Phishing
Falsely claiming to be a legitimate company to scam the consumer; asks for usernames, passwords, bank and personal info
Match each description with the given piece of hardware. Firewall Router Hub Swithc
Firewall-controls communication authorizations to or from a computer or network Router-controls the movement of data between networks Hub-central node that connects multiple devices, but cannot pinpoint another single device Switch-Central node that connects multiple devices and can distinguish between devices
fs la [location]
LIST ACCESS -Displays the user access list for the directory specified by location -no location shows access list for the current directory
fs mkm BACKUP users.unityid.backup
MOUNT A BACKUP (must be in ~/) -Mounts a backup with the name BACKUP (or whatever directory name the user wants to create) to the current directory -The backup contains the contents of the user's AFS space as it existed at midnight the previous night. ***This command must be executed in the user's home directory.***
Student ID Number
NOT your Unity ID; nine digit number on card.
fs rmm BACKUP
REMOVE A BACKUP (must be in ~/) -Removes a mounted directory named BACKUP. ***This command must be executed in the user's home directory.***
Required/Optional email fields
REQUIRED: -To: enter as many addresses separated by commas -Subject: relevant heading accurately describing message contents OPTIONAL: -Cc: Carbon Copy sends others a copy of the email -Bcc: Blind Carbon Copy sends copy w/o recipients in To: or Cc: fields knowing about it
Tilde-slash "~/"
Relative Pathname to home directory
fs sa [location] [unityid] [access_list]
SET ACCESS -Sets the user access list for the directory specified by location, granting the rights specified by access_list to unityid -[access_list] options: rlidwka,all,none
Create a log file of all commands executed
Script [-option] [location/]file_name.txt -options: -a (append the log file to an existing one) -f (flushed - outputs contents of file as commands are entered) -type "exit" to end log file
What does TLI stand for?
Text Line Interface
Filtering (email)
To move emails out of your inbox automatically into labels
Match the operating system with its user interface. Each answer choice may be used more than once (GUI,CLI,TLI,GUI w/ CLI): Windows 7 DOS DOS running a program Terminal Linux Mac OS X
Windows 7 - GUI DOS - CLI DOS running a program - TLI Terminal - TLI Linux - GUI w/ CLI Mac OS X - GUI w/ CLI
Device drivers are like a ____________ for the kernel . a. manual b. piece of junk c. application d. piece of hardware
a
Does a hard drive have more or less capacity than a floppy disk? a. More b. Less c. About the same d. I love floppy disks!! e. What, pray tell, is a floppy disk?
a
This port was common on computers allowing the user to connect to the network and internet back during the 1980's through 1990's. a. Modem b. Ethernet c. VGA d. DVI
a
What type of relationship maintains that one computer is a server, while the other one is a client? a. Classic View b. Peer-to-Peer c. Inverted View d. Symbiotic View e. None of these
a
Which of the following allows data to travel between devices? a. Data bus b. Address bus c. Control Bus d. System Bus e. Collisions
a
Which of the following is a valid IPv4 address? a. 127.0.0.1 b. 192.168.1256.1 c. 2001:db8:0:1234:0:567:1:1 d. 2001:db8:85a3:0:0:8a2e:370:7334
a
Which of the following is a valid IPv4 address? a. 127.0.0.1 b. 192.168.256.1 c. 2001:db8:0:1234:0:567:1:1 d. 2001:db8:85a3:0:0:8a2e:370:7334
a
Which of the following is an expansion slot for a laptop computer? a. ExpressCard b.PCI c. AGP d. PCI Express
a
In the "Computer Analogy" supplement... what is (in general) a computer's hardware being compared to? CPU = · Hard Drive = · RAM = · Graphics Card = · Removable disks = · Device drivers =
a kitchen CPU = Head Chef · Hard Drive = Fridge or Pantry · RAM = Counter space · Graphics Card = Sous Chef · Removable disks = Tupperware · Device drivers = Recipes or Instruction manuals
Virtual Computing Lab
a method of remotely accessing and using a University machine to access programs needed for a class that are not available on personal computer
File System
a methodology by which data and information are stored on storage devices (hard drives, floppy disc, etc.), making them easily retrieved
Worm
a program that copies of itself, but does not infect other programs
Virus
a program that replicates itself, usually by attaching itself to other files and programs
Network License
agreements between software companies and the network owners for network software
File Extensions
allow the computer's operations system to know what application software should be used to open the file; added by the computer but can be typed by user in file name
Nomad System
allows a active University computing accounts to access the campus network anywhere on campus through wired or wireless; if you loose connection or close computer or idle for more than two hours you have to reconnect.
What should you backup?
applications that you do not have installation disks for such as school assignments, email, address book, music files, pictures, internet bookmarks..
A Star network typically has how many concentrators? a. 0 b. 1 c. 2 d. 3 e. 4
b
What does NAT stand for? a. Natural Address Translator b. Network Address Translation c. Neural Allocator for Transmutation d. Network Addressor Tidbit e. Does not stand for anything
b
What is the individual piece of software that a kernel uses to interface with a particular piece of hardware? a. API b. Device driver c. GUI d. Interface e. None of these
b
What is the individual piece of software that a kernel uses to interface with a particular piece of hardware? a. API b. Device driver c. GUI d. Interface e. None of these
b
What protocol do we use in order to connect to our AFS space through applications such as PuTTY? a. SFTP b. SSH c. Tunneling d. Piping e. None of these
b
Which of the following allows data to know its destination? a. Data bus b. Address bus c. Control Bus d. System Bus e. Collisions
b
Which of the following is actually a type of hard drive configuration rather than hard drive interface? a. SATA b. RAID c. SCSI d. IDE
b
Which of the following is actually a type of hard drive configuration rather than hard drive interface? a. SATA b. RAID c. SCSI d. IDE
b
What feature of SSH makes it nearly impervious to attacks? a. Spelunking b. Tunneling c. Ninjas d. Encryption e. Snipers
b/d
Root of a File Tree
beginning of the file system, all other nodes trace back to it
Password restrictions
between 8 and 127 characters, no Unity ID, one number and letter, not a dictionary word, no 5 consecutive numbers, not your old password.
According to the online textbook, how many types of memory are there within a computer? a. 0 b. 1 c. 2 d. 3 e. 4
c
How many bits are in a Megabyte (using software amount)? a. 2000 b. 1024^2 c. 1024^2 * 8 d. 2000 * 8 e. Too many to count
c
What is the core part of an operating system? a. Interface b. Driver c. Kernel d. Shell e. None of these
c
What is the role of a server in a P2P relationship? a. Client b. Server c. Both d. Neither
c
Which of the following devices generally works between networks rather than within an individual network? a. Hub b. Switch c. Router d. Node
c
What types of service can a kernel provide? Choose all that apply. a. Creation of Files b. Kernels are useless! c. Virtual File System d. Scheduling e. Managing code
c/d
adware
codes included by authors delivers advertising banners displayed while program is running; justification: recover programming development cost and lower user cost BUT...
This port is used exclusively for video with newer monitors. a. Modem b. Ethernet c. VGA d. DVI
d
What does VLAN stand for? a. Viral LAN b. Visual LAN c. Video LAN d. Virtual LAN e. None of these
d
What does WAN stand for? a. Windows Area Network b. Windows Area Navigation c. Wide Area Navigation d. Wide Area Network e. None of these
d
What technology automatically assigns addressing on the network? a. RDP b. VCL c. DNS d. DHCP e. SSH
d
What term is used to identify the process in which certain programs have priority for the processor, in other words, sets up a queue? a. Multi-tasking b. Shell c. Control bus d. Scheduling e. None of these
d
rm [-option] [location/]file_name
deletes file or directory -options: -r (recursive) - must have when deleting directories -f (forced) - deletes w/o asking permission
Trojan Horse program
do not replicate nor copy themselves, but rely on other "manual" methods of distribution
NCSU-guest
does not require log in using Nomad and only internet access
Decimal is a base _____ system. a. 2 b. 0 c. 1 d. 5 e. 10
e
Unity ID
eight lowercase characters - determined be the user's first and middle initials, and the first six characters of the user's last name; file storage, email, academic records and personal information
EOS System Command Prompt
eos% **not part of the command itself**
Standard command format
eos% commandname -options file_LOCATION file_DESTINTION
File Names
files are given names so computer users can easily remember the data within
NCSU
have to log in with Unity ID and password; have access to internet and AFS; always needed for E115
How do you protect from viruses
install virus protection program and keep up to date; NCSU requires antivirus installation on computers connected to server..provides it for free (Trend Micro)
Campus resources
internet, backup, email, help desk, applications in labs/classrooms
Default Password
last four digits of student ID and four digits of birth month and day
man [-option] command
more information about a command -use up/down arrows to navigate -press "q" to return to main screen
Password Recommendations
one special character, one capital and one lowercase letter.
Command Arguments
paths to files
spyware
programming put in someone's computer to secretly gather info about the user and relay it to advertisers or other interested parties; installed with Limewire, iMesh, Morpheous
Unity accounts
provides users with access to the NCSU computing network and its many resources
Device registration
register to avoid logging in to ncsu every time. if device is stolen, have to unregister immediately. re-register periodically
Malicious Use
run virus scans to prevent unwanted .exe files if there is a difference in file icons
Antivirus programs
search for, detect, and attempt to remove these viruses
Commands
short character combinations that the computer is programmed to understand
Relative Pathnames
shortcut pathnames to a directory or file
Effects of adware/spyware
slow computer function, jumpy internet, altered home pages
Freeware
software is written and distributed w/o compensation, everyone has access; usually packages that everyone needs
Buyware
software that can be purchased for the full software price, and, by opening it, you are the owner of the license
Operating System (OS)
software that controls the internal hardware of the computer; auto-updates but sometimes adware disables so manual updates sometimes
Labels (email)
sort and organize similar emails
Login info for Terminal on Mac / Linux
ssh -X [email protected]
Andrew File System
storage and primary file space when using a UNIX system; the home directory on Solaris or Linux station and available as K: drive thru Windows; store web files available thru ww4.ncsu.edu
File
string of bytes
File Tree
system of directories (folders) and files
Where are the majority of I/O ports found on a desktop computer?
the back
Absolute Pathnames
the long form of the pathname to a specific directory or file in the file tree
Most important part of the file system
the method by which files are indexed on the hard drive; allows OS to know at any time where to find a file on the hard drive; different methods for different OS
How viruses are spread
through email attachments, instant messaging links and attachments, comprised web servers, pirated Software, Usenet news groups, Internet Relay Chat channels, floppy disks, file downloads
University emails
[email protected]; gmail; more storage space than previous
Papercut system
used to print on NCSU campus; pay through AllCampus accounts; auto linked to lab machines so can print directly from computer only when connected to NCSU system; can only print .pdf from laptops
Shareware
users have a limited amount of time that they can use the program before being required to purchase the full version of the software; certain features disabled until purchase of full version
