1. UNIX/LINUX
TRAINING
Michael Olafusi
+234-808-938-2423

2. DAY 1 – INTRODUCTION & INSTALLATION
DAY 2 – LINUX DESKTOPS & ADMINISTRATION
DAY 3 – LINUX CLI ADMINISTRATION
DAY 4 – LINUX NETWORKING & INTERNET
DAY 5 – LINUX SERVER & PROGRAMMING

3. Introducing
UNIX/Linux

4. Linux and UNIX
• Linux is an open-source clone of UNIX, the most secure
and mature operating system.
• The major difference between Linux and UNIX is that UNIX
is trademarked to The Open Group, while Linux is Open-source.
• All command line tools work the same on both.
• Over 90% of the supercomputers in the world run Linux.
And the 10 fastest run Linux.
• Linux is the leading operating system on Servers
• Linux is free and popular distributions (distros) are
Ubuntu, Fedora/Red Hat, OpenSUSE, Mandriva, Mint,
ArchLinux, Slackware…

5. Benefits of UNIX/Linux
• Low cost and very stable (some Linux servers are
not rebooted for over a year, try that with
Windows server!).
• Best multi-user, multitasking OS.
• Most secure OS. Hence, it’s popularity as a
server OS.
• Best computing power and inbuilt network
support
• Fastest developing OS, with the most number of
developers.

6. Linux Distributions
• A Linux distribution consists of the Linux kernel (actual
OS) and a collection of applications
– Linux Kernel
– X Window System
– Graphical Desktops (GNOME, KDE…)
– Applications
• GNU Software is at the heart of every Linux. Besides
the Linux Kernel, GNU software/utilities come next
• GNOME and KDE are the most popular graphical
desktops
• Ubuntu, Mandriva, OpenSUSE, RoboLinux, Slackware,
Xandros, Debian GNU, Fedora, Gentoo, Knoppix,
Linspire

7. Linux
Installation

8. Linux Installation
• Similar installation process across all distros
• Live CDs, to try the Linux without installing
• Setting aside Space for Linux – Root folder,
Home folder & Swap space
• Most secure OS. Hence, it’s popularity as a
server OS.
• Burning the Linux ISO image on DVD or making a
Bootable Flash Drive
• Doing the actual installation (Ubuntu as sample)

9. Linux Installation
• Best Practice requires the following on separate partitions
– Swap
– /
– / boot
– /home
– /usr
– /opt
– /var
• This type of partitioning scheme comes in handy when you have problem
with your hard disk
• Swap partition is used to boost your computer memory and some
applications require it, even the hibernate feature on Linux requires it.
Rule of Thumb is to set at 2x the RAM

10. Installing Ubuntu

11. Installing Ubuntu – Beginning

12. Installing Ubuntu – Linux File system

13. Installing Ubuntu – Creating Account

14. Installing Ubuntu - Completed

15. Linux
Desktops

16. Linux Desktops
• The most common Desktops are GNOME and
KDE (just cosmetic differences and default
programs)
• Popular GNOME distros are Ubuntu & Fedora
• Popular KDE distros are Kubuntu & OpenSUSE
• Opening the Terminal Windows and 6 Virtual
Consoles
• Navigating the Linux File System
• Linux Applications

17. Linux File System

18. Linux File Types
• Ordinary files: These are regular files. (white/black)
• Directories: These are files that contains other files and directories, and provide
pointers to them. (blue)
• Symbolic links: These special files link to another file, in a different location.
(Cyan)
• Block and character device files: All physical devices in Linux are represented by
device files. e.g. /dev/sda (yellow)
• Socket file: Provides protected inter-process networking. (Purple)
• Named Pipe file: Like socket files but doesn’t use network socket semantics.
(Red)
• $ ls –l indicates all these types
– -rw-r--r-- ordinary file
– brw-rw---- block device file
– crw-rw-rw- character device file
– drwxr-xr-x directory file
– lrwxrwxrwx symbolic file
– srw-rw-rw- socket file
– prw-rw-rw- named pipe file

19. Linux/Unix
Administration

20. Linux Administration
• Linux has become extremely easy to administer,
compared to its early days. And can be administered
using GUI applications (like Windows OS) or using the
Commandline Interface (CLI)
• As a professional Linux administrator, you’ll have to
know how to administer the OS via the CLI
• Linux supports multi-tasking, several users using the OS
simultaneously.
• By default 7 users can work simultaneously (without
anyone logging out). 6 Commandline users and 1 GUI
user. To switch use CTRL + ALT + F1 (F2,F3,F4,F5,F6,F7) .
CTRL+ALT+F7 takes you to the GUI one
• From the GUI, you can always access the commandline
via “Terminal”

21. Linux Administration

22. Linux – User Administration
• To show the Linux distro version: $ cat /proc/version
• To see Linux kernel version: $ uname –r
• To add new user: #useradd michael
• To view the default useradd options: # useradd –D
• The options are:
– -g Group
– -m Home directory
– -f Inactive (to set password expiry date in days)
– -e Expire (to disable the user after specified number of
days)
– -s Shell (user’s default login shell, usually /bin/sh)
• To delete a user: # userdel –r michael

23. Linux – CLI Key Combination
• Ctrl + A to mover the cursor to the beginning of
command line
• Ctrl + C to end a running program and return the
prompt
• Ctrl + D to log out of the current shell session, same as
exit or logout
• Ctrl + E to move cursor to the end of the command line
• Ctrl + H to generate backspace character
• Ctrl + L to clear the terminal
• Ctrl + R to search command history
• Ctrl + Z to suspend a program
• Shift + PageUp or PageDown to scroll (browse buffer)
• Tab to autocomplete command of filename
• Tab Tab to show command completion possibilities

24. Linux CLI useful tips
• If you can’t remember a command but remember the first 2
or more letters, type them and press Tab twice. This will list
all the commands that start with those letters.
• If you can’t remember how to use a particular command,
type man command e.g. man mkdir to read a comprehensive
help file on using the command, mkdir.
• If you need a quick help with using the options or syntax of a
command, type command --help (double hypen). e.g. mkdir -
-help to get a quick help guide.
• To get an easy to read manual (easier than man) on any
command, type info command e.g. info mkdir
• To get a short description of what a command does, type
whatis command e.g. whatis mkdir
• To get a list of commands for doing a particular task, type
apropos task e.g. apropos text to get text manipulation
commands/applications

25. Linux CLI text manipulation
• Use cat file.txt to display the content of file.txt on the
screen
• Use cat file.txt | more to display the content of file.txt
one page at a time
• Use cat file.txt | less to enable scrolling. Press q to
exit/end.
• Use tac file.txt to display the content of file.txt in
reverse
• Use cat file1.txt > file2.txt to copy content of file1 to
file2, file duplication.
• Use cat file1.txt >> file2.txt to append content of file1
to file2.
• Use tail -10 file.txt to display the last 10 lines in file.txt
• Use head -10 file.txt to display the first 10 lines in
file.txt

26. Linux CLI file permission
• All files in Linux have permissions set (or unset) for user, group and other
users. It’s indicated as –rwxrwxrwx or similar.
• To display a file’s permission settings, type ls -l filename
• The first character indicates the file type – ordinary file, directory…
• The next 3 characters indicate the permission for the file owner (user),
then next 3 for users in the owner’s group and the last 3 for other users.
• r = Read w = Write x = Execute
• Easiest way to change a file’s permission is to use chmod u/g/a +/- rwx
filename e.g. chmod a+w file.txt to give everyone write permission on
the file, file.txt
• You can also use numeric arguments and common ones are –
– chmod 400 to give only read permission to owner
– chmod 600 to give read and write permission to owner
– chmod 644 to give everyone read permission and the owner write permission
– chmod 775 to give everyone read + execute, owner + group read write execute
permission
– chmod 777 to give everyone read write exceute permission

27. Linux CLI execution modes
• By default any command you run in the command line terminal
runs in the foreground, and locks that particular terminal session
till it finishes executing.
• You can also make commands run in the background, so they
don’t lock the terminal session and you can start other commands
while they are still running.
• To run a command in the background, type the symbol & after the
command (put a space in between)
• Only run commands that do not require user interaction in the
background.
• Type and execute jobs to show commands running in the
background
• Whenever you run a command in the background, it is assigned a
process number, n. To refer to this (command execution) process,
use %n.
• To move a command process to the foreground, type fg %n (n is
the command process number)

28. Linux Administration - Performance
• To a user, performance means quick execution of
commands, while to a system administrator, it
means ability to do much more. As the
Administrator, you’ll have to optimize system
performance for the whole system – users,
programs and services.
• Issues that can impair performance are –
– programs that are not optimized for the system
– problem with access to disks, controllers, display, other
required interfaces
– network issues affecting communication with out systems
– amount of users working simultaneously on the system

29. Linux Administration - Scheduling
• There are times you will want a command or script
to run at a particular time of the day or run while
you are at lunch break.
• Basically, there are three types of scheduling –
– Using sleep to wait fore specified seconds before running
the command. e.g. lp file1; sleep 900; lp file2; sleep 900;
lp file3 (this is to insert 15mins between each file print, to
allow other users print in between)
– Using at command to run a command at a specified time.
– Using cron to schedule a command or script on a
monthly, weekly, daily or hourly basis

30. Linux Administration – Output Redirection
• Piping the output to another command using |
• Redirecting output via >
• Redirecting output via >> (to append)
• Redirecting only errors via 2>
• Redirecting standard input via <
• Use tee option with | (pipe) to copy input to
standard output (terminal) and more than one
output files. e.g. cat original | tee copy1 copy2
• Use tee –a to append to files. e.g. cat file.txt | tee -a
file_all.txt

31. Linux Administration – Output Manipulation
• Grep: It scans output line per line, searching for
matching patterns.
– All lines containing the pattern will be printed to standard
output. e.g. cat countriesandcapitals.txt | grep Nigeria
– This can be reversed using the –v option.
• Sort: It allows you to sort the output lines before
displaying.
– Default is in alphabetical order. e.g. cat alphabets | sort
– It can also sort by file size, when sorting ls output. e.g. ls
~/ -la | sort -nk 5
– And when used with uniq, it can sort and filter out double
entries. e.g. sort itemlist | uniq

32. Linux Administration – Vi(m) Editor
• vi editor is a very powerful text editor that comes pre-installed
on nearly all Linux OS.
• vim is variant of vi editor, basically an improved version.
Practically, it is more error tolerant than vi.
• There are two modes –
– Command mode, which is the default mode. You basically
scroll through the file content or enter commands.
• h moves the cursor to the left,
• l moves it to the right,
• k to move up, and
• j to move down
• dd will delete current line
• :w to save (write) the changes made
• :q will exit the editor
• :q! will exit the editor without saving changes

33. Linux Administration – Vi(m) Editor contd
– Text input mode. You enter this mode by pressing the
Insert key. There are some basic guidelines to note -
• don’t attempt to scroll or change the cursor position in this
mode, position the cursor where you want to add extra text
before changing to the text input mode. The only exception is
when you are using vim.
• To change to this mode pressing -
– a will append, move the cursor one position to the right before
switching to the inserting mode
– i will insert
– o will insert a blank line under the current cursor position and
move the cursor to that line
• Vim is better, just not as pre-installed on Linux OSs
as Vi.
• Run vimtutor to start a recommended 30 minutes
tutorial on using vim.

34. Linux Administration - Commands
man any_command <To view the manual for target command>
pwd <Print current working directory>
ls <Show files in current directory>
ls –a <Show maximum information about all files, including hidden>
mv source destination <Move/rename a file or directory>
rm target <Delete target, could be file or directory>
cp source destination <Copy file or directory>
mount /dev/device_name /media/device_name <Mount filesytem>
umount /media/device_name <Unmount>
df –h <display all mounted filesystem and available disk space in KB, MB,
GB>
du <display disk usage, very useful for routine maintenance>
ps – ef <List all running processes, with full details>
top <Standard system monitor showing a more extensive view of all
processes and system resources>
nohup command & <Start a process in the background and have it keep
running after you log off>
~/ <Current user's home directory>
ifconfig <Configure network interfaces>
iwconfig <Configure wireless network interfaces>

35. Linux Administration - Commands
ssh username@ip_address <Connect to a remote server>
ping ip_address <Check to see if target is online and responding>
traceroute6 ip_address <View network route to target>
netstat <Network Monitor>
iptables –L <View firewall rules>
adduser <Create a new user>
usermod <Change user privileges (be very careful with this one)>
deluser <Delete user>
chmod <# Change privileges over file or directory >
chown user_name:group_name directory_name <Change owner of a file or
directory>
su username <Temporarily become a different user>
users <Print usernames of logged in users>
Infact, you can administer your mysql database directly from the CLI
CREATE DATABASE databasename; <New database>
CREATE USER username@localhost IDENTIFIED BY 'password'; <Create a
new user>
show tables; <Show database schema>

36. Unix Command
Utilities

37. UNIX Utilities/Commands
awk Processes files
cat Displays files (and is used with other tools to
concatenate files)
cmp Compares two files
comm Compares sorted files, and shows differences
cp Copies files
cpio Copies and backs up files to an archive
cut Selects characters or fields from input lines
dd Copies and converts input records
diff Compares two text files, and shows differences
dump Backs up files
fdformat Formats a floppy disk at a low level
file Displays the file type
find Finds files within file tree
fmt Formats text very simply
grep Matches patterns in a file
groff Processes embedded text formatting codes

38. UNIX Utilities/Commands
gzip Compresses or decompresses files
head Displays the first part of a file (first 10 lines by default)
ispell Checks one or more files for spelling errors
less Displays files allowing for scrolling forward and
backward (pauses when screen is full)
ln Creates a link to a file
lpr Sends a file to a printer or printer device
ls Lists file and directory names and attributes
man Displays documentation for commands
mkbootdisk Creates a CD (or floppy disk on older distributions)
from which to boot a system
mkdir Creates a new directory
mkfs Builds a UNIX/Linux file system
mount Mounts file systems and devices
mv Renames and moves files and directories
newfs Creates a new file system (used in UNIX systems in
particular)

39. UNIX Utilities/Commands
pr Formats text files for printing and displays them
pwd Shows the directory you are in
rdev Queries or sets the root image device
restore Restores files (from a dump)
rm Removes files
rmdir Removes directories
sed Edits streams (noninteractive)
sort Sorts or merges files
tail Displays the last lines of files (last 10 lines by default)
tar Copies and backs up files to a tape archive
touch Changes file modification dates
uniq Displays unique lines of a sorted file
wc Counts lines, words, and bytes
whereis Locates information about a specific file

40. UNIX Utilities/Commands
pr Formats text files for printing and displays them
pwd Shows the directory you are in
rdev Queries or sets the root image device
restore Restores files (from a dump)
rm Removes files
rmdir Removes directories
sed Edits streams (non-interactive)
sort Sorts or merges files
tail Displays the last lines of files (last 10 lines by default)
tar Copies and backs up files to a tape archive
touch Changes file modification dates
uniq Displays unique lines of a sorted file
wc Counts lines, words, and bytes
whereis Locates information about a specific file

41. UNIX Utilities/Commands
date Sets and displays date and time
df Displays the amount of free space remaining on disk
du Summarizes file space usage
file Determines file type
finger Displays detailed information about users who are logged in
free Displays amount of free and used memory in the system
edquota Displays user disk quotas and enables them to be changed
kill Terminates a running process
ps Displays process status by process identification number and
name
sleep Suspends process execution for a specified time
top Dynamically displays the status of processes in real time
uname Shows information about the operating system
vmstat Shows information about virtual memory use
w Displays detailed information about the users who are l
ogged in
who Displays brief information about the users who are logged in

42. UNIX Utilities/Commands
tp Transfers files over a network
ifconfig Sets up a network interface
netstat Shows network connection information
nfsstat Shows statistics for Network File
ping Polls another network station (using TCP/IP); great for a fast
determination about whether your network connection is
working
rcp Remotely copies a file from a network computer
rlogin Logs in to a remote computer
route Displays routing table information, and can be used to
configure routing
rsh Executes commands on a remote computer
showmount Lists clients that have mounted volumes on a server
telnet Connects to a remote computer on a network
traceroute Shows the route along a network between the source device
and the destination, such as from a computer to a server
wvdial Controls a modem dialer for dial-up connections over a phone
line

43. LINUX in a Network
• Linux has the most robust networking tools and support
• All the possible means of connecting to the internet
work on Linux
– Digital Subscriber Line (DSL)
– Cable Modem
– Dial-up Networking
– Wireless Internet access points
• Works seamlessly in a Local Area Network and has
inbuilt security tools
• Configurable network management files/tools, located
in the /etc directory.
• An arsenal of Network troubleshooting tools

44. LINUX – Network Configuration
• Linux network configuration files are –
– /etc/hosts This contains addresses of hosts that can be
contacted without using an external naming service like
DNS. It always contains 127.0.0.1
– /etc/resolv.conf This file configures access to a DNS
server. It contains your domain name and the name
server(s) to contact
– /etc/nsswitch.conf This file defines the order in which to
contact different name services.
• Linux Network configuration commands include –
– ifconfig to display and configure the network interfaces
– ip is a newer and better command. Sample use include ip
addr show and ip route show

45. LINUX – Network Troubleshooting
• Linux network commands are –
– host to display information on hosts or domains. e.g. host
www.telemit.com
– ping to check if a host is alive. You can interrupt by
pressing Ctrl+C
– traceroute to check the route that packets follow to a
network host. e.g. traceroute www.telemit.com
– whois to lookup a specific domain information
• In addition you can install several network
troubleshooting and optimizing tools for free on
Linux.

46. Linux Internet

47. LINUX and your Internet needs
• Mozilla Firefox, Konqueror, Epiphany, Chromium and
Opera Browser to access the web
• Mozilla Thunderbird, Evolution, Zimbra, kontact and
Kmail to do exactly what Outlook does
• Graphical FTP clients like gFTP, KFTPGrabber and
even Firefox, in addition to the commandline tool
FTP
• Linux can be configured as a Mail server, web server,
FTP server, call manager, CMS server or Database
server. And all without buying a complex expensive
software.

48. Linux Security

49. Linux Security - Security Framework
• Determine security requirements
• Perform risk assessments
• Establish a security policy
• Implement a robust software + hardware
security solution
• Continuously monitor and manage the
security solution

50. Linux Security – Security Threats
• Denial of Service attacks
• Unauthorized Access
• Unauthorized release of confidential
information
• Configuration loopholes
• Network loopholes

51. Linux Security – Security Solutions
• Authentication
• Access Control
• Encryption
• Password policies
• Firewalls
• Physical security of all hardware and data
• Intrusion Prevention systems
• Intrusion detection systems

52. Linux Servers

53. Linux Servers
• Web server
• FTP server
• Mail server
• DNS server
• InterNetNews (INN) server
• DB Server
• SIP Server

54. Linux Servers – File sharing
• Network File System
– For sharing files with other Linux/UNIX systems (or PCs
with NFS client software)
• Samba
– For file sharing and print sharing Windows systems

55. Linux
Programming

56. Linux Programming
• Linux comes with software development
tools pre-installed
• Compiling source code applications
• Shell Scripting
– Most powerful tool of a Linux administrator
– Used to automate routine administrative tasks
– Used to monitor system performance and vital directories
(especially database directories for enough free space)
– Makes administration of lots of computers extremely
easy and less error-prone

57. Linux Programming – Shell Scripting
• Bash shell scripts are the most used
• A simple shell script is
#!/bin/bash
clear
echo "Good morning, world.“
# save it as morning in any folder of choice e.g. ~/Documents
# to run the script give it the executable file permission
# using chmod 755 ~/Documents/morning
# to run the script, type ~/Documents/morning

58. Additional Online Resources
• Introduction to Linux
http://tille.garrels.be/training/tldp/index.html
• Linux Newbie Administration Guide
http://lnag.sourceforge.net/downloads/LinuxNe
wbieAdministratorGuide.pdf
• Bash Guide for Beginners
http://tille.garrels.be/training/bash/
• Ubuntu Pocket Guide & Reference
http://ubuntupocketguide.com/download_main
.html

59. INTERESTED?

60. CALL: +234-808-938-2423
E-MAIL: MICHAEL@OLAFUSIMICHAEL.COM