1-Accessing the Command Line

!

metacharacter that is used to expand previous commands without having to retype them

!historyCommandNumber

Execute a specific history entry

Virtual Console

One of multiple logical consoles that can each support an independent login session. If the graphical environment is available, it will run on the first virtual console in Red Hat Enterprise Linux 7. Five additional text login prompts are available on consoles two through six (or one through five if the graphical environment is turned off). With a graphical environment running, access a text login prompt on a virtual console by pressingCtrl+Alt and pressing a function key (F2 through F6). Press Ctrl+Alt+F1 to return to the first virtual console and the graphical desktop.

Anything followed by ...

Represents an arbitrary-length list of items of that type

Workspaces

Separate desktop screens which have different application windows. Can be used to organize the working environment by grouping open application windows by task.

$

Shell prompt indicator showing user is running as regular user

window list

The bar that runs along the bottom of the screen. Provides an easy way to access, minimize, and restore all windows in the current workspace. On the right corner an indicator to tell the user which workspace they are on and how many are available.

Command

The name of a program to run.

Option

The part of the command line that adjusts the behavior of a command.

dash

also called the dock, this shows a configurable list of users favorite applications, running applications, and a grid button which can be used to select arbitrary applications

head -n 20

display the top 20 lines of a file

command --help

Causes command to print a description of what it does, a "usage statement" that describes the command's syntax

semicolon ;

Character to separate multiple commands on a single line

Ctrl+u

Clear from the cursor to the beginning of the command line

GNU Bourne-Again Shell (bash)

A program that interprets commands typed in by the user, an improved version of sh

Ctrl+Alt+F2-F6

Access text login prompt on a virtual console

passwd

Command to change the users password

date

Command to show current date and time

wc

Count lines, words and characters in a file

Ctrl+Right Arrow

Jump to the end of the next word on the command line

Enter

Key pressed to execute a command

Tab

Key pressed to quickly complete commands or filenames once they have typed enough to make it unique, if characters are not unique yet, pressing this key twice displays all commands that begin with the chars already typed

Multiple items separated by pipes |

Means only one of them can be specified

wc -w

Show number of words in a file

Activities Overview

Special mode that helps user organize windows and start applications. Shows the dash, windows overview, and workspace selector. Super key opens.

Applications > Utilities > Terminal or right click desktop or activities overview grid button

Starting a terminal

Prompt

The visual cue that indicates an interactive shell is waiting for the user to type a command.

Ctrl+k

Clear from the cursor to the end of the command line

Ctrl+Left Arrow

Jump to the beginning of the previous word on the command line

Ctrl+e

Jump to the end of the command line

date +%R

Show current time

wc -c

Show number of characters in a file

wc -l

Show number of lines in a file

Square brackets, [ ]

Surrounds optional items

Ctrl+Alt+UpArrow or Ctrl+Alt+DownArrow

Switching between workspaces sequentially

Argument

The part of the command line that specifies the target that the command should operate on.

file

This command scans the beginning of a file's contents and displays what type it is.

Places menu

This menu to the right of the Applications menu provides quick access through a graphical file manager to important menus in the user's home directory, to /, and to exports and file shares on the network.

+

This symbol before a date command argument specifies a format string

#

shell prompt indicator showing that user is running as superuser root

date +%x

Show current date

Terminal

An interface that provides a display for output and a keyboard for input to a shell session.

!stringcommand

Execute the most recent string command

desktop environment

Graphical user interface on a Linux System

Ctrl+a

Jump to the beginning of the command line

Ctrl+Alt+F1

Return to the first graphical console and the graphical desktop

Ctrl+r

Search the history list of commands for a pattern

top bar

The bar that runs along the top of the screen. It provides the Applications and Places menus and controls for volume, networking, calendar access, and selecting between keyboard input methods. Under the menu for the user's name are options to adjust account settings, lock the screen, switch users, log out or shut down.

Physical Console

The hardware display and keyboard used to interact with a system.

Shell

The interpreter that executes commands typed as strings.

history

displays a list of previously executed commands prefixed with a command number

tail

displays bottom 10 lines of a file

head

displays the top 10 lines of a file

message tray

provides a way to review notifications sent by applications or system components to GNOME. If a notification occurs, normally the notification first appears briefly as a single line at the bottom of the screen, and a persistent indicator appears in the lower right corner to inform the user of how many notifications have been recently received. It can be opened by pressing Super+m and closed by Esc or Super+m again.

Applications Menu

this menu on the top bar provides a way to start applications, categorized into submenus. The Activities Overview can also be started from this menu.