It Fundamental QUIZ 1

cp/copy

Copy file

ls

List contents

ls -l

List contents in a long listing

mv/move

Move or rename file

rm/del

Delete file

cat, more, less/type

Display text file contents

mkdir

Create directory

rmdir

Delete directory (must be empty)

cd

Change directory

pwd

Print working directory

ls -d *

List all files and directories but don’t list the contents

rm -r

Deletes all content

rm -ir

Asks permission before deleting all items in order

touch

Create file

sudo useradd

Create user

usermod

Modify an existing account

chmod

Change permission file

chown

Change a file’s ownership and group ownership

chgrp

Change a file’s group ownership

rwx

Read, write, execute

ugo

User, group, other

read

4 in numerical

write

2 in numerical

execute

1 in numerical

/etc/passwd

Go to password

In passwd “-e”

Creates an expiration date for the password

In passwd “-w”

Tells user that the account will expire in a number of days

$

The shell

.bash_history

Shows all commands used since beginning

!!

Repeats last command

Ctrl p

Shows the previous used command

Ctrl n

Shows the next command

Head

Shows first 10 lines of file

Tail

Shows last 10 lines of file

cd ..

Move up one level

alias

An extra name for something, can be used to shorten commands

grep/egrep

Search one or more files for the specified regular expression

*

Means everything

?

Means any one character

Variable

Can be created by using (-NAME=value)

echo

Outputs whatever you want

command > file

Redirects output to file, overriding if it exists

command >> file

Redirects output to append to file, creating if it doesn’t exist

command < file

Redirect input to come from file

command | command

Known as a pipe, takes output of one command as input to the next

man

Manual page, shows basically everything

Sequential access

Data in a file accessed in a linear fashion

Direct access

Data in a file accessed directly by specifying logical record numbers

Parent directory

The containing directory

Subdirectory

The directory being contained

Root directory

The directory at the highest level

Path

Text designation of the location of a file or subdirectory

Absolute path

Path that begins at the root and includes all successive subdirectories

Relative path

Path name that begins at the current working directory

CPU

Responsible for executing programs and performing the fetch-execute cycle

Memory

Used to store both executable program code and data

SRAM

Cache, registers

DRAM

Main memory

ROM

Read-only memory

Operating System

System software that is an interface between the user and the hardware

Shadow file

Where passwords are stored

Passwd file

Only shows “x” as password

IPOS Cycle

Input, processing, output, storage cycle

Processing (in IPOS cycle)

Includes data movement, I/O, arithmetic/logic operations, and branches

Branches

Change to another location in the program

Data movement

Move data between CPU and memory

I/O

Move data between CPU or memory and I/O device

Arithmetic/Logic operations

Computation

Abstraction

A mental model that removes complex details

IT Roles

System admin, network admin, database admin, web admin, web development, security admin

System admin

Administers computers in an organization

Network Administrator

Maintains and secures computer network

Database Administrator

Maintains database and database management system

Web Administrator

Maintains website through web server

Web Developer

Designs and creates web pages and scripts

Security Administrator

Secures systems and creates security policies

IT Skills

Troubleshooting, knowledge of operating systems, system level programming, system security, hardware

Troubleshooting

Detect a problem, diagnose its cause, find a solution

Knowledge of Operating Systems

Installation and monitoring