CMPEN441 RedHat Quizes

Operating System Definition

OS is a resource allocator ◦ Manages all resources ◦ Decides between conflicting requests for efficient and fair resource use OS is a control program ◦ Controls execution of programs to prevent errors and improper use of the computer

what does fg do

brings a task back from the background

Caching

copying information into faster storage system; main memory can be viewed as acache for secondary storage

Solid-state disks

faster than hard disks, nonvolatile ◦ Various technologies ◦ Becoming more popular9

how is everything stored in linux

files in tree format

ssh

secure shell can access remotely from a server

System BUS

: Provides for communication among processors, main memory, and I/O modulesSupporting components (e.g. power supply, bus, fans, case)

Hard disks

rigid metal or glass platters covered with magnetic recording material ◦ Disk surface is logically divided into tracks, which are subdivided into sectors ◦ The disk controller determines the logical interaction between the device and the computer

Which item represents a number that identifies the group at the most fundamental level? A Primary group B UID C GID D Groupid

C GID

Which pattern matches only file names that begin with an uppercase letter? A ^?* B ^* C [upper]* D [[:upper:]]* E [[CAP]]*

D [[:upper:]]*

Which directory contains files to boot the system? A /boot B /home/root C /bootable D /etc

A /boot

Which directory contains persistent, system-specific configuration data? A /etc B /root C /run D /usr

A /etc

Which output redirection operator sends output to a file and sends errors to a different file? A > file 2> file2 B > file 1> file2 C > file &2> file2 D | tee file

A > file 2> file2

Which pattern matches only file names with at least three characters? A ???* B ??? C \3* D +++* E ...*

A ???*

Which term describes the part of the command line that specifies the target that the command should operate on? A Argument B Command C Option D Prompt

A Argument

Which item or file represents the location of the user's personal files? A Home directory B Login shell C /etc/passwd D /etc/group

A Home directory

Which term describes the hardware display and keyboard to interact with a system? A Physical Console B Virtual Console C Shell D Terminal

A Physical Console

Which pattern matches only file names that begin with "b"? A b* B *b C *b* D [!b]*

A b*

Which command returns to your current home directory, assuming that the current working directory is /tmp and your home directory is /home/user? A cd B cd .. C cd . D cd * E cd /home

A cd

Which Bash command is used to display the file type? A file B less C cat D history E view

A file

Which command displays the absolute path name of the current location? A cd B pwd C ls ~ D ls -d

B pwd

The set of steps that the Kernel takes to switch from one task to another in a CPU is Called

Context Switch

operating system

Managing all these components requires a layer of software

Interrupts

Mechanism by which other modules may interrupt the normal sequencing of theprocessor.

what is a system call

calls the OS context switch

!!

reruns the last command

Time multiplexing:

sharing time of use of processor, I/O, etc.

su

switch user

command to check how long a system has been running

uptime

> vs >>

> overrides content in file >> appends to the new location

Resources Managed by OS

CPU Memory Storage I/O devices

What is the fourth field of the /etc/passwd file? A Home directory B UID C Login shell D Primary group

D Primary group

3. Which pattern matches only file names where the first character is not "b"? A b* B *b C *b* D [!b]*

D [!b]*

Classes of Interrupts

Program Timer I/O Hardware failure

Space multiplexing:

sharing space on memory, disk

what is SIGINT

when you press CNTRL c it kills the process

Which Bash shortcut or command separates commands on the same line? A Pressing Tab B history C ; D !string E Pressing Esc+.

C ;

Uniprogramming

The processor spends a certain amount of time executing, until itreaches an I/O instruction; it must then wait until that I/Oinstruction concludes before proceeding

2 Types of multiplexing

Time multiplexing: Space multiplexing:

An operating system is interrupt driven T/F

True

sudo

switches the user to the root user and executes from there

what is considered a zombie program

when the child fishes executing but the parent is still waiting

what is a PCB and what does it stand for

-Process control block -context of a process

things stored in a stack

-local variables -function parameters -return addresses

Which pattern matches only file names that contain a number? A *#* B *[[:digit:]]* C *[digit]* D [0-9]

B *[[:digit:]]*

Which pattern matches only file names that end with "b"? A b* B *b C *b* D [!b]*

B *b

Which directory is the top of the system's file-system hierarchy? A /etc B / C /home/root D /root

B /

Which item or file represents the location of the local user account information? A Home directory B /etc/passwd C /etc/UID D /etc/group

B /etc/passwd

Which item represents a number that identifies the user at the most fundamental level? A Primary user B UID C GID D Username

B UID

Which term describes one of multiple logical consoles that can each support an independent login session? A Physical Console B Virtual Console C Shell D Terminal

B Virtual Console

Which command changes the working directory to the parent of the current location? A cd ~ B cd .. C cd ../.. D cd -u1

B cd ..

Multiprogramming

There must be enough memory to hold the OS (resident monitor) and one user programWhen one job needs to wait for I/O, the processor can switch to the other job, which is likelynot waiting for I/O Also known as multitasking Memory is expanded to hold three, four, or more programs and switch among all ofthem7

how to add a new user to the terminal

add userer

Asymmetric Multiprocessing

each processor is assigned a specie task.

Symmetric Multiprocessing

each processor performs all tasks

Secondary storage

extension of main memory that provides large nonvolatile storage capacity

shell scrips must be compiled and executed

false

can a process go from blocked to running

no

can a signal create a new process

no

Main memory

only large storage media that the CPU can access directly ◦ Random access ◦ Typically volatile

& in command Linux line

sends a tasks to the background

Which command returns you to the working directory before the current working directory? A cd - B cd -p C cd ~ D cd ..

A cd -

Storage Device Hierarchy

1 registers 2 cache 3 main memory 4 solid state drive 5 hard disk 6 optical disk 7 magnetic tapes

Which Bash shortcut or command re-executes a specific command in the history list? A Pressing Tab B !number C !string D history E Pressing Esc+.

B !number

Which output redirection operator discards all messages that are normally sent to the terminal? A > file 2> file2 B &> /dev/null C &> /dev/null 2> file D &> file

B &> /dev/null

Which directory contains user home directories? A / B /home C /root D /user

B /home

Which term describes the name of a program to run? A Argument B Command C Option D Prompt

B Command

Which command creates an empty file called helloworld.py in the user home directory, assuming that your current directory is /home? A touch ./helloworld.py B touch ~/helloworld.py C touch helloworld.py D touch ../helloworld.py

B touch ~/helloworld.py

Which pattern matches all file names that contain a "b"? A b* B *b C *b* D [!b]*

C *b*

Which directory contains system files to access hardware? A /etc B /run C /dev D /usr

C /dev

Which directory contains non-persistent process runtime data? A /tmp B /etc C /run D /var

C /run

Which directory contains installed software programs and libraries? A /etc B /lib C /usr D /var

C /usr

Which directory contains regular commands and utilities? A /commands B /run C /usr/bin D /usr/sbin

C /usr/bin

Which output redirection operator displays output to a terminal and discards all error messages? A &> file B 2> &> file C 2> /dev/null D 1> /dev/null

C 2> /dev/null

Which output redirection operator sends output and errors to the same file and preserves the file content if it exists? A > file 2> file2 B &> file C >> file 2>&1 D >> file 1>&1

C >> file 2>&1

Which item represents the program that provides the user's command-line prompt? A Primary shell B Home directory C Login shell D Command name

C Login shell

Which term describes the part of the command line that adjusts the behavior of a command? A Argument B Command C Option D Prompt

C Option

Which term describes the interpreter that executes commands that are typed as strings? A Command B Console C Shell D Terminal

C Shell

Which command changes the working directory up two levels from the current location? A cd ~/.. B cd ../ .. C cd ../.. D cd ~/

C cd ../..

Which command changes the working directory to /tmp if the current working directory is /home/student? A cd tmp B cd .. C cd ../../tmp D cd ~tmp

C cd ../../tmp

Which Bash command is used to change a user's password? A password B pass C passwd D usermod E userpassword

C passwd

Which Bash command displays the last five lines of the /var/log/messages file? A head -n 10 /var/log/messages B tail 10 /var/log/messages C tail -n 5 /var/log/messages D tail -l 10 /var/log/messages E less /var/log/messages

C tail -n 5 /var/log/messages

Which output redirection operator sends output to both the screen and a file at the same time? A &> /dev/null B > file 2> file2 C | tee file D | < file

C | tee file

Which output redirection operator sends both output and errors to a file, and creates it or overwrites its contents? A | tee file B 2 &> file C 1 &> file D &> file

D &> file

Which item or file represents the location of the local group information? A Home directory B /etc/passwd C /etc/GID D /etc/group

D /etc/group

Which directory is the administrative superuser's home directory? A /etc B / C /home/root D /root

D /root

Which output redirection operator saves output to a file and discards all error messages? A &> file B | tee file 2> /dev/null C > file 1> /dev/null D > file 2> /dev/null

D > file 2> /dev/null

Which Bash shortcut or command copies the last argument of previous commands? A Pressing Ctrl+K B Pressing Ctrl+A C !number D Pressing Esc+.

D Pressing Esc+.

Which Bash shortcut or command is used for completing commands, file names, and options? A ; B !number C history D Pressing Tab E Pressing Esc+.

D Pressing Tab

Which term describes the visual cue that indicates that an interactive shell is waiting for the user to type a command? A Argument B Command C Option D Prompt

D Prompt

Which term describes an interface that provides a display for output and a keyboard for input to a shell session? A Console B Virtual Console C Shell D Terminal

D Terminal

Which Bash shortcut or command displays the list of previously executed commands? A Pressing Tab B !string C !number D history E Pressing Esc+.

D history

Which command lists files in the current location, with a long format, and including hidden files? A llong ~ B ls -a C ls -l D ls -al

D ls -al

Which Bash shortcut or command jumps to the beginning of the command line? A !number B !string C Pressing Ctrl+LeftArrow D Pressing Ctrl+K E Pressing Ctrl+A

E Pressing Ctrl+A

PSW

Program Status Word Contains a list of bits Each bit represents a status or an event within the computer system. These Bits are called "Flag Bits"

System Bus

Provides for communication amongprocessors, main memory, and I/Omodules4

When you shut down a computer what loses its data

RAM

kernel

The core functionality of an operatingSystem "The one program running at all times on the computer"

Device Driver

device controller to manage I/O ◦ Provides uniform interface between controller and kernel10