This document provides an overview of Linux GUI and command line tools. It discusses X Window System and display managers that control graphical login. It also describes desktop environments like KDE and GNOME that provide additional functionality to the GUI. The document outlines basic shell commands for listing files, accessing terminals, writing shell scripts, and getting command help. It concludes with a summary of topics including basic system administration tasks like installation, updates, user maintenance and troubleshooting.

1. ACE Course CT01558
Linux Introduction
Linux GUI & Command Tools

2.  X, DM, KDE and GNOME
 Other X Graphical User Interfaces
 Command Line Tools
 Shells, bash options, shell scripts
 Basic administration
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Agenda
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3.  X11, or “X Window System” is the a distributed
client/server software as well as protocol
 http://en.wikipedia.org/wiki/X_server
 Display Manager
 Controls WHO logs into display
 If GUI crashes, it restarts itself again!
 In most distributions, you can’t login as root to DM
 Each GUI has its version: KDM, GDM, MDM, …
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X & Display Managers

4.  Controls the placement & appearance of application
windows (frames, titles, icons)
 Metacity in GNOME
 KWin in KDE
 Xfwm in Xfce
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Window Managers

5.  Provide additional functionality to GUI with:
 Control panel
 cut & paste
 trash can
 file manager
 multimedia tools, music & wallpapers!
 notepad, calendar, calculator
 shared libraries for those programs
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Desktop Environments (DE)

6.  Most Popular Desktop Environments are:
 KDE http://kde.org/
 GNOME http://www.gnome.org/
 Xfce http://xfce.org/
 Much more exist!
 Common Desktop Environment (CDE)
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Linux Desktop Environments

7. 7
Basic Linux Usage
Accessing a terminal in a GUI environment

8.  Graphical interface
 Start GUI environment on top of BASH shell
 Or, switch to a graphical terminal
e.g., GNOME Display Manager (gdm)
Graphical Interface

9. Shells, Terminals, and the Kernel
 From the local server, use key combinations to change to
separate terminal
 Command-line terminal may be accessed from GUI
environment
 Command line prompt:
 Root user: #
 Regular user: $

10.  Commands: indicate name of program to execute
 Case sensitive
 Options: specific letters starting with “-” appearing
after command name
 Alter way command works
 Arguments: specify a command’s specific working
parameters
Basic Shell Commands

11.  ls command: List the files in a directory
 May pass an argument indicating the directory to be
listed
 –F option: Argument to indicate file types
 –l option: Argument to list long file listings
Linux+ Guide to Linux Certification, 3ed 11
Listing Files

12. Basic Shell Commands (continued)
Some common Linux commands

13. Shell Metacharacters
 Metacharacters: characters with
a special meaning
 e.g., $
 Refers to a variable
 Avoid use of metacharacters
when typing commands unless
using their special functionality
 Single quotation marks ‘ ’ protect
metacharacters from being
interpreted specially by the shell

14.  A shell script is a script written for the shell
 Operations: backups, file manipulation, program
execution, and printing text
 A script needs to be “flagged” as an executable “x”
with the chmod command
 If you are running a script from current directory it
needs to be preceded by “./”
Shell Scripts

15. Getting Command Help
 Manual (man) pages: most common form of
documentation for Linux commands
 type “man” followed by command name
 contains different sections
 Searchable by keyword
 Info pages: set of local, easy-to-read command syntax
documentation
 type “info” followed by a command name

16.  Start/Stop/Reboot Server
 Backup critical or User files
 Install NEW software or services
 Update EXISTING software
 Add/Remove users
 Troubleshoot
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Basic Administration

17. Linux#3 - Commands 17
System Stop or Reboot
 To reboot:
 shutdown –r
 reboot
 init 6
 To halt:
 shutdown –s
 halt
 init 0
 You must be administrator!
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18.  Adds
functionality to
your system,
example:
install LibreOffice
or MySQL
 From Command
line mode:
 sudo apt-get
mysql
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Install Software

19.  Keeps your
system safe and
bug-free
 From Command
line mode:
 sudo apt-get
update
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Update Software

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Monitoring & Process Control
 top – displays top processes
 uptime + ps = w
 ps ax – list of all running processes
 nice PID priority – changes priority level
 Default priority is 10, it can be changed
 from -20 (highest priority) to 19 (lowest)
 kill –signal PID
 killall process
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21.  useradd <username>
 passwd <username> //changes password for a user
 userdel <username>
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User Maintenance

22.  Installation Fails
 Server crashes
 Service(s) not running
 Read LOGS! /var/log/messages
 Restart in single user mode [init S]
 Check file system for errors
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Troubleshooting

23.  KDE and GNOME
 Other X Graphical User Interfaces
 Command Line Tools
 Shells, bash options, shell scripts
 Basic administration
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Summary
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24. Questions???