IT training RH124 RHEL7

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Red Hat System

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Administration I
Student Workbook

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RH124-RHEL7-en-1-20140606
MAN-RH124SKE-R2


Comprehensive, hands-on training that solves real world problems

Red Hat System
Administration I
Student Workbook

©

2014 Red Hat, I n c .

R H 1 24- R H EL 7-en-1-201406 0 6


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RED HAT SYSTEM

ADMINISTRATION I


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RH124

Red Hat Enterprise Linux 7 RH124

Red Hat System Administration I

Edition 1

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Authors:

Susan Lauber, Philip Sweany , Rudolf Kastl, George Hacker

Editor:

Steven Bonneville

Copyright©

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2014 Red Hat. Inc.

The contents of this course and all its modules and related materials, including handouts to
audience members, are Copyright©

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2014 Red Hat, Inc.
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No part of this publication may be stored in a retrieval system, transmitted or reproduced in
any way, including, but not limited to, photocopy, photograph, magnetic, electronic or other
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record, without the prior written permission of Red Hat, Inc.
This instructional program, including all material provided herein, is supplied without any
guarantees from Red Hat. Inc. Red Hat, Inc. assumes no liability for damages or legal action

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arising from the use or misuse of contents or details contained herein.
If you believe Red Hat training materials are being used, copied, or otherwise improperly
distributed please e-mail or phone toll-free (USA)
or

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+1(866) 626-2994

+1(919)754-3700.

Red Hat, Red Hat Enterprise Linux, the Shadowman logo, JBoss, Hibernate, Fedora, the
Infinity Logo, and RHCE are trademarks of Red Hat. Inc., registered in the United States and
other countries.
Linux® is the registered trademark of Linus Torvalds in the United States and other
countries.
Java® is a registered trademark of Oracle and/or its affiliates.

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XFS® is a registered trademark of Silicon Graphics International Corp. or its subsidiaries in
the United States and/or other countries.

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The OpenStack® Word Mark and OpenStack Logo are either registered trademarks/service

marks or trademarks/service marks of the OpenStack Foundation, in the United States

and other countries and are used with the OpenStack Foundation's permission. We are not

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affiliated with, endorsed or sponsored by the OpenStack Foundation, or the OpenStack
community.

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All other trademarks are the property of their respective owners.

C o n t r i buto rs: Rob Locke, Bowe Stri c k l a n d , Scott M c B r i e n , Wa n d e r Boesse n ko o l , Fo rrest Tay l o r

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Reviewers: M i c h a e l P h i l l i ps, D a v i d B u c k n e l l , A a ro n H i c ks, J a y R a m s u rr u n
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D o c u m e n t C o nve n t i o n s

ix

N otes a n d Wa r n i n g s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i x
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I ntro d u c t i o n

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1.

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27
The L i n u x F i l e System H i e ra rchy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Practice: File Syste m H i e ra rchy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Locat i n g Fi l es by N a m e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Practice: Locat i n g F i l e s and D i rectories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
M a n a g i n g F i l es U s i n g C o m m a n d - L i n e Too l s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Pract ice: Co m m a n d- L i n e F i l e M a n a g e m e n t . . .. . . . . . . . .. .. . . . . . . . . . . . . .. . . .. .. .. . . . .. . . . . . .. .. .. .. .. . . . . . . 46
M a tc h i n g F i l e N a mes U s i n g Pat h N a m e E x p a n s i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Pract ice: Pat h N a m e E x p a n s i o n .. .. .. .. . . . . . . .. . . . . . . . . .. . . . .. .. . . . . . . . . . . . . . . . . . . . .. . .. .. .. . . . . . . .. .. .. .. . . . . 52
Lab: M a n a g i n g F i l es with S h e l l Expa n s i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

M a n a g i n g F i l es Fro m t h e C o m m a n d L i n e

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Gett i n g He l p in R e d Hat E nt e r p r i s e L i n u x

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Rea d i n g Docu m e ntation U s i n g m a n C o m m a n d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Practice: U s i n g t h e m a n C o m m a n d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Rea d i n g Docu m e ntation U s i n g pi nfo C o m m a n d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Practice: U s i n g the p i nto Co m m a n d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Rea d i n g D o c u m e ntation in /u s r/s h a re/d o c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Practice: V i ew i n g Package D o c u m e n t at i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Gett i n g H e l p Fro m Red Hat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . 74
P ractice: C rea t i n g a n d View i n g a n SoS R e p o rt . .. . . . . .. . . . . . . . . . . .. .. .. .. .. . . . . . . . . . . .. .. .. . . . . . . . . .. . . . 79
L a b : V i ew i n g and Printing Help Doc u m e nt a t i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

4 . Creat i n g, V i e w i n g, a n d E d i t i n g Text F i l e s

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Red i re c t i n g O u t p u t to a F i l e or Pro g r a m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Practice: 1/0 Red i rection and P i pe l i n es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
E d i t i n g Text F i l es from t h e S h e l l Pro m p t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 5
P ractice: E d it i n g F i l es with V i m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Editing Text F i l es with a G ra p h i ca l Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Practice: Copy i n g Text Between W i n d ows . .. . . . . . . .. .. .. . .. .. . . . . . .. .. . . . . .. .. .. . . . .. .. . .. .. .. .. .. . . . . .. . 1 03
L a b : C reat i n g , V i e w i n g , a n d E d i t i n g Text F i l es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0 5

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1
Access i n g t h e C o m m a n d L i n e U s i n g t h e Loca l Conso l e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
P ractice: Loca l C o n s o l e Access Ter m s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Access i n g t h e C o m m a n d L i n e U s i n g t h e D e s ktop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
P ractice: The G N O M E 3 Desktop Envi ro n m e n t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3

Exe c u t i n g Com m a n d s U s i n g t h e Ba s h S h e l l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5
P ractice: Bash C o m m a n d s a n d Keyb o a rd S h o rtcuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 9
L a b : Acces s i n g t h e Com m a n d L i n e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2

Acces s i n g t h e C o m m a nd L i n e

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R e d H a t Syst e m A d m i n istra t i o n I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x i
O r i e n t a t i o n to t h e C l assroom E n v i ro n m e n t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x i i
I nternati o n a l i z a t i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x i i i

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U sers a n d G r o u p s
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Practice: U s e r a n d G ro u p Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 6
G a i n i n g S u p e r u s e r Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 8
P ractice: R u n n i n g C o m m a n d s a s root . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 2
M a n a g i n g L o c a l U s e r Accou nts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 5

M a n a g i n g Loca l L i n u x Us e rs a n d Gro u p s

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Practice: C reat i n g U s e rs U s i n g Co m m a n d - l i n e Too l s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M a n a g i n g Loca l G ro u p Acco u nts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: M a n a g i n g G r o u p s U s i n g Co m m a n d - l i n e Too l s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M a n a g i n g U s e r Passwords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pra c t i ce: M a n a g i n g U s e r Pa ssword Aging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lab: M a n a g i n g Loca l L i n u x Users and G ro u ps . . . .. . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.

7.

C o n t ro l l i n g Access to F i l es w it h L i n u x F i l e Syst e m Pe r m i s s i o n s

L i n u x F i l e Syste m Pe r m i s s i o n s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: I nterpret i n g F i l e a n d D i rectory Pe r m i s s i o n s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M a n a g i n g F i l e Syst e m Perm i s s i o n s from the C o m m a n d L i n e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: M a n a g i n g F i l e Secu rity f r o m t h e C o m m a n d L i n e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M a n a g i n g Defa u l t P e r m i s s i o n s a n d F i l e Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: Contro l l i n g N e w F i l e Pe r m i s s i o n s a n d O w n e rs h i p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lab: C o n t ro l l i n g Access to Fi l es with L i n u x F i l e Syst e m Permissions . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M o n itori n g a n d M a n a g i n g L i n u x Processes

Processes
Pra c t i ce: Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contro l l i n g J o b s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: B a c kg ro u n d and Fo re g ro u n d Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
K i l l i n g Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: K i l l i n g P rocesses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M o n i t o r i n g P rocess Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: M o n i t o r i n g P rocess Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lab: M o n it o r i n g a n d M a na g i n g L i n u x Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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8.

C o n t ro l l i n g S e rv i c e s a n d D a e m o n s

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C o nfi g u r i n g a n d S ec u r i n g O p e n S S H S e r v i c e

I d e n t ify i n g Auto m a t ica l l y Started System Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: I d e ntify t h e S t a t u s o f sys t emd U n its . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contro l l i n g Syst e m Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: Using sys t emc t l to M a n a g e S e rvices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lab: Contro l l i n g S e rvices a n d Daemons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10.

128
130
132
134
137
139
143
144
148
150
1 53
155
1 59
1 61
165
166
170
172
175
177
1 81

1 83
1 87
189
195
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2 07

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Access i n g t h e R e m ote C o m m a n d L i n e w i t h S S H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Practice: Access i n g t h e Remote Co m m a n d Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1 5
Conf i g u r i n g S S H Key-based A u t h e ntication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Pra c t i ce: U s i n g SSH Key-based A u t h e n t i c a t i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
Custo m i z i n g SSH Service Config u ra t i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 0
Prac t i ce: Rest r i c t i n g S S H Log i n s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 2
Lab: Confi g u ri n g a n d S e c u r i n g O p e n S S H Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 5

A n a l yz i n g a n d Sto r i n g L o g s

System Log Arch itect u re . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: Syste m Log g i n g C o m p o n e nts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rev i ew i n g Sys log F i l es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: F i n d i n g Log Entries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Review i n g syst e m d J o u r n a l Entries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: F i n d i n g Eve nts With j o u rn a l ct l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prese rvi n g the syst e m d J o u r n a l .. .. . . . . . .. .. .. . . . . . . .. . . . . . . . . . . . . . . . . .. . . .. . . . . . . . . . . .. . . . . . . . . . . . .. . . . . . .
Practice: Confi g u re a Persistent syste md J o u r n a l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M a i n ta i n i n g Acc u rate T i m e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Prac t i ce: Adj u s t i n g System Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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L a b : A n a l y z i n g a n d Sto r i n g Logs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
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N etwo r k i n g Concepts
258
Practice: Netwo r k i n g C o n ce pts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
Va l id a t i n g N etwo r k Confi g u ra t i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
Practice: Exa m i n i n g N etwork Config u rati o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
Config u ri n g N etwo r k i n g w i t h nmcli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Practice: Config u r i n g Netwo r k i n g with nmcli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
E d i t i n g N etwo rk Config u ra t i o n F i l es .. . . . . . . . . . . . . . . . . . . . . .. .. . . . . . . . .. . . . . . . . . . . . . . . . .. .. . . . . . . . . . . . . . .. .. 279
Practice: E d i t i n g N etwo r k Confi g u ra t i o n F i l es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
Config u ri n g H ost N a mes and N a me Reso l ut i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
Practice: Config u r i n g Host N a m es and N a m e Reso l ut i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 8 5
L a b : M a n a g i n g Red Hat E n t e r p rise L i n u x N etwo r k i n g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 8 8

M a n a g i n g R e d H a t E nt e r p r i s e L i n u x N etwo r k i n g

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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12.

A r c h i v i n g a n d C o py i n g F i l e s Between Syst e m s

13.

I n sta l l i n g a n d Upd a t i n g S oftware Pa c ka g e s

14.

Acces s i n g Li n u x F i l e Syste m s

15.

Us i n g V i r t u a l ized Syste m s

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M a n a g i n g C o m p ressed t a r A rc h ives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: Backing Up and Restor i n g F i l es Fro m a t a r A r c h ive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Copy i n g F i l es Between Syst e m s S e c u re l y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: Copy i n g F i l es Over the N etwo r k W i t h s c p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
S y n c h ro n i z i n g Fi l es Betwee n Syste m s S e c u re l y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: Sy n c h ro n i z i n g Two D i recto ries S e c u re l y With r sync . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lab: A rc h i v i n g and Copy i n g F i l es Betwee n Systems .. .. . . . .. . . . .. . . . . .. .. . . . . . . . . . . . . . . . . . . . . . . . . .. .
Atta c h i n g Syste m s to S u b s c r i p t i o n s for Software U pdates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: Red H a t S u bs c r i p t i o n M a n a g e m e n t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
R P M Softwa re Pa ckages and Yu m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: R P M Softwa re Pa c k a g e s . . . . . . .. .. . . . .. . . . . . .. .. .. .. .. . .. . . . .. .. . . . . .. . . . . . . . . . .. .. . . . .. . . . . . . .. ..
M a n a g i n g Softwa re U p d ates w i t h yum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: Insta l l i n g a n d U pd a t i n g Softwa re with y um . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
E n a b l i n g yum Softwa re Repositories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: E n a b l i n g S oftwa re Repositories . . . .. . . . . . . . . . . . . . . . . . . . . .. . . . . . .. . . . . . .. . . . . . . . . . . . . . . . . . . . .. ..
E xa m i n i ng R P M Package F i l es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: Wo r k i n g with R P M Package F i l es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
L a b : I nsta l l i ng a n d U pd a t i n g S oftwa re Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I d e ntifying F i l e Syste m s a n d Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: I d e ntifyi n g F i l e Syst e m s a n d Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M o u nt i n g a n d U n m o u n t i n g F i l e Syste ms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: M o u n t i n g and U n m o u nt i n g File Syste m s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M a k i n g L i n ks Betwee n F i l e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: Making L i n ks Betwee n F i l e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Loca t i n g F i l es o n the Syste m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ..
Practice: Locat i n g F i l es o n the System . . . . . . . . . . .. . . . . . . . . . . . . .. . .. .. . .. .. .. . . . .. . . .. . . . . . . . . . . . . . . . . . . . .
Lab: Acces s i n g L i n u x F i l e Systems . . . . . . . . . . . . . . . . . . . . . . . .. .. . . . . . . .. . . . .. .. .. . . . . . .. .. . . . . . . . . . . .. . . . . . . . .
M a n a g i n g a Loca l V i rt u a l i z a t i o n H ost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Practice: M a n a g i n g a Loca l V i r t u a l izatio n H ost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I n sta l l i n g a New V i rt u a l M a c h i n e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
P r a c t i c e : I nsta l l i n g a New V i rt u a l M a c h i n e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C h a pter Test: U s i n g V i rt u a l i z e d Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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403
Red H a t System A d m i n istra t i o n I C o m p re h e n s ive Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404
L a b : C o m p re h e n s i ve Review
408

C o m p re h e n s ive Review

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Document Conventions
N otes a n d Wa r n i n g s

Note
" N otes" a re t i ps, s h o rtcuts or a l te r n a t ive a p p roaches to t h e t a s k at h a n d . I g n o r i n g a
note s h o u l d have no neg ative c o n seq u e n ces, but you m i g h t m i s s o u t o n a t r i c k t h a t
m a kes yo u r l ife e a s i e r.

'

Important
" I m porta n t " boxes deta i l t h i n g s t h a t a re e a s i l y m i ssed: confi g u ra t i o n c h a n g e s t h a t
o n l y a p p l y to t h e c u rrent sess i o n , o r s e r v i c e s t h a t need resta rt i n g befo re a n u pdate
w i l l a p p l y. I g n o r i n g a box l a b e l e d " I m porta n t " w i l l n ot cause data loss, but m a y cause
i r r i t a t i o n a n d f r u st ra t i o n .

Warning
" Wa r n i n g s " s h o u l d n ot be i g n o red. I g n o r i n g wa r n i n g s w i l l most l i k e l y c a u s e data l oss.

R

References
" Refere n ces" d e s c r i b e w here to f i n d exte r n a l d o c u m entation re l eva n t to a s u bject.

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Introduction
Red H at Syste m Ad m i n ist ra t i o n I
Red Hat System Administration I ( R H1 24) is d e s i g n e d for I T p rofess i o n a l s without prev i o u s
L i n u x system a d m i n i stration e x p e r i e n ce. T h e cours e i s i nt e n d e d to p rovide s t u d e n t s w i t h L i n u x
a d m i n istra t i o n " s u rviva l s k i l l s " by foc u s i n g o n core a d m i n istra t i o n tas ks. Red Hat System
Administration I a l so p rovides a fo u n d a t i o n fo r students p l a n n i n g to become fu l l -t i m e L i n u x
syste m a d m i n istrators by i n t ro d u c i n g key com m a n d - l i n e c o n c e pts a n d e nterprise- l evel too l s .
These con cepts a re f u r t h e r deve l o ped i n t h e fol l ow-on cou rse, Red Hat System Administration I I
( R H1 34).

C ourse o bjectives
•

•

G a i n s u ff i c i e nt s k i l l to pe rfo r m core syste m a d m i n is t rat i o n t a s ks on Red Hat Enterprise L i n u x .

B u i l d fo u n datio n a l s ki l l s needed by a n R H CSA-ce rtified R e d Hat Enterprise L i n u x system
a d m i n i st rator.

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Audience
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•

IT p rofessiona l s a c ross a broad ra n g e of d i s c i p l i n es w h o n e e d to p e rfo rm esse nti a l L i n u x
a d m i n istration tas ks, i n c l u d i n g i n s ta l l at i o n , esta b l is h i n g network c o n n ectivity, m a n a g i n g
physica l storage a n d b a s i c s e c u rity a d m i n istra t i o n .

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P rere quisites
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T h e re a re no fo rma l prere q u i s ites for t h i s course; however, p rev i o u s system a d m i n istrat i o n
e x p e r i e n c e on ot h e r o p e rat i n g syste ms wi l l be ve ry b e n e fi c i a l .

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I nt ro d u c t i o n
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O rie ntat i o n to t h e C l ass ro o m E nvi ro n m e n t
I n t h i s cou rse, students w i l l d o most h a n d s-on practice exercises a n d l a b work with two c o m p u t e r
syste ms, w h i c h w i l l be refe rred to a s d e s k t o p a n d s e rve r. These m a c h i n e s h a v e t h e h o s t
n a m es d e s ktop X.exa m p l e.com a n d se rverX.exa m p l e.com, w h e re t h e X i n t h e comp uters' host
n a m es w i l l be a n u m be r that w i l l vary from st u d e n t to stu d e n t . Both m a c h i n es have a sta n d a rd
u s e r accou nt. student, with t h e password student. T h e root password o n both system s is redhat.

I n a l ive i n st r uctor- l e d c l a s s room, s t u d e nts w i l l be a s s i g n e d a p hys i ca l computer ( " fo u n d a t i o nX"),
w h i c h wi l l b e used to access t h ese two m a c h i nes. The d e s k t o p a n d se rve r system s a re v i rtu a l
m a c h i nes r u n n i n g on t h a t host. S t u d e nts s h o u l d l o g into t h i s m a c h i n e a s u s e r kiosk w i t h t h e
pa ssword redhat.
O n fo u n d a t i o nX, a spec i a l co m m a n d ca l l e d r h t - vmc t l is used to work w i t h t h e d e s k t o p a n d
se rve r m a c h i nes. T h e co m m a n d s i n t h e fo l l ow i n g ta b l e s h o u l d be r u n a s t h e kiosk u s e r o n
fo u nd a t i o nx, a n d c a n be u s e d w i t h s e rver (a s i n t h e exa m p l es) o r d e s k t op.

rht - vmc t l

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Commands

Action

Co m m a n d

Start se rve r m a ch i n e

r h t - vmc t l s t a r t se rve r

V i ew " p hysica l conso l e " to l o g i n a n d work
with se rve r m a c h i n e

r h t - vmc t l view se rver

Reset se rve r mach i n e to its prev i o u s state
a n d resta rt v i rt u a l m a c h i n e

r h t - vm c t l r e s e t server

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A t t h e start o f a l a b exerc ise, if t h e i n st r u ct i o n " reset yo u r se rve r " a p p e a rs, t h a t mea n s t h e
c o m m a n d r h t - vm c t l r e s e t s e r ve r s h o u l d b e r u n i n a p ro m pt o n t h e f o u n d a t i o nX system a s
u s e r kiosk. L i kewi se, if t h e i n st r u c t i o n " reset you r desktop" a p p e a rs, t h a t m e a n s t h e co m m a n d
r h t - vmc t l reset d e s k t o p s h o u l d b e r u n on fou n d a t i o nX a s u s e r kiosk.
E a c h st u d e n t is on t h e 1 Pv4 network 172.25.X.0/24, w h e re t h e X matches t h e n u m b e r
o f t h e i r d e s ktopX a n d se rve r X syst e m s. T h e i n st r u ctor r u n s a c e n t ra l u t i l ity server,
c l a s s room .exa m p l e.co m , w h i c h acts a s a ro uter for t h e c l a s s ro o m n etworks a n d provides D N S,
D H C P, H T T P, a n d other content services.
Classroom Machines

Machine name

I P a d d resses

Role

d e s ktopX.exa m p l e.com

172.25.X.1 0

Stu d e nt " c l i e nt" c o m p u t e r

serverX.exa m p l e.com

172 .25.X.11

Student " s e rver" c o m p u t e r

c l a s s room .exa m p l e.com

172.25.254.254

C l a ss room u t i l ity s e rver

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Inte r n a t i o n a l i z a t i o n
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I nte rn a t i o n a I izat i o n
Language support
Red Hat Enterprise L i n u x 7 offi c i a l l y s u ppo rts 22 l a n g u a g es : E n g l i s h , Assa m ese, Ben g a l i , C h i n ese
( S i m p l ified), C h i n ese (Tra d it i o n a l), Fre n c h , G e r m a n , Guj a ra t i , H i n d i , I ta l ia n , J a p a n ese, Ka n n a d a ,
Kore a n , M a l a ya l a m , M a ra t h i , O d i a , Port u g u ese ( B ra z i l i a n), P u nj a b i , R u s s i a n , S p a n i s h , Ta m i l , a n d
Te l u g u .

Per-user language selection
U sers m a y p refe r to u s e a d ifferent l a n g u a g e for t h e i r d e s ktop e n v i ro n m e n t t h a n t h e syste m ­
wide defa u lt. They m a y a l so want to s e t t h e i r a c c o u nt to use a d iffe rent keyboa rd l ayout or i n p ut
method.
L a n g u a g e sett i n g s

I n the G N O M E d e s ktop enviro n m e nt , t h e u s e r m a y be p ro m pted t o s e t t h e i r prefe rred l a n g u a g e
a n d i n p ut method o n fi rst l o g i n . I f n ot. t h e n t h e e a s i est w a y for a n i n d i v i d u a l user to a dj u st t h e i r
prefe rred l a n g u a g e a n d i n p ut m e t h o d sett i n g s i s to use t h e R e g i o n & L a n g u a g e a p p l ication. R u n
t h e co m m a n d gnome - co n t rol - c e n t e r r e gion, or from t h e t o p b a r, s e l ect (User)> Sett i n g s .
I n the w i n d ow t h a t o p e n s , select R e g i o n & L a n g u a g e . The user ca n click t h e La n g u a g e box and
s e l ect their preferred l a n g u a g e from t h e l ist t h a t a p pea rs. T h i s wi l l a l so u pdate t h e Fo r m a t s
sett i n g to the defa u l t for that l a n g u age. T h e n ext time t h e user logs in, t h ese c h a n g e s w i l l t a ke
f u l l effect.
These sett i n g s affect the G N O M E d e s ktop e n v i ro n ment and any a p p l i c a t i o n s , i n c l u d i n g gnome ­

t e rminal, started i n s i d e it. H owever, t h ey d o n ot a p p l y to t h a t acco u nt if a ccessed t h ro u g h a n
s s h l o g i n from a remote system o r a l o c a l text c o n s o l e (s u c h a s t t y2).

Note

-

A u s e r c a n m a ke t h e i r s h e l l e n v i ro n m e nt u s e t h e s a m e LANG sett i n g as t h e i r g ra p h ic a l
e n v i ro n m e nt. eve n w h e n they l o g i n t h ro u g h a t e x t conso l e o r ove r s s h . O n e w a y to d o
t h i s i s to p l a c e code s i m i l a r to t h e fo l l ow i n g i n t h e u s e r ' s - / . bas h r c f i l e. T h i s exa m p l e
c o d e w i l l s e t t h e l a n g u a g e u s e d o n a text l o g i n to match t h e o n e c u rrent l y s e t f o r t h e
u s e r ' s G N O M E d e s ktop en vi ro n m e n t :

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i=$ (grep ' Language = ' /var/lib/AccountService/users/${USER} \
I sed ' s/Language=// ' )
if [ "$i" ! = " " ] ; then
export LANG=$i
fi

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J a p a n ese, Korea n , C h i n ese, o r ot h e r l a n g u a g es w i t h a non-Latin c h a racter set m a y not
d i s p l ay p ro p e r l y o n lo ca l text c o n s o l es.
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I n d iv i d u a l c o m m a n d s c a n be m a d e to use a n o t h e r l a n g u a g e by sett i n g the LANG va r i a b l e o n the
com m a n d l i n e :

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r
I

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[user@host -]$

LANG=fr_FR . utf8 date

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I n t roduction

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j eu . avril 24 17 : 55 : 01 CDT 2014

L-- ---�-- -·· -------

S u bs e q u e n t c o m m a n d s w i l l reve rt to u s i n g t h e syste m ' s defa u lt l a n g u a g e for o u t p u t . T h e locale
com m a n d ca n b e used to c h e c k the c u rrent va l u e of LANG and ot h e r re l ated e nv i ro n m e n t
va r i a b les.

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I n p u t m e t h o d setti n g s

GNOME 3 i n Red Hat E n t e r p rise Linux 7 a uto m a t i c a l l y uses t h e I B u s i n p u t method s e l ection
system, which m a kes it easy to change keyboa rd layouts and i n put methods q u i c k l y.
The

Reg i o n & L a n g u a g e

a p p l ication c a n a l so be u s e d to e n a b l e a l te r n a t ive i n p u t m e t h o d s. I n t h e
a p p l ication's w i n d ow, t h e I n p u t S o u rces b o x s h ows w h a t i n put m e t h o d s a re

c u rre n t l y ava i l a b l e . By defa u lt, E n g l i s h (US) m a y be t h e o n l y ava i l a b l e m e t h o d . H i g h l i g h t E n g l i s h
(US) a n d c l i c k t h e key b o a rd i c o n to see t h e c u r re n t keyb o a rd l ayout.
Region & Language

To a d d a n o t h e r i n p ut method, c l i c k the + b utto n a t the bottom l eft of the I n p u t S o u rces w i n d ow.
An A d d a n I n p u t S o u rc e w i n d ow w i l l o p e n . S e l ect yo u r l a n g u a ge, a n d t h e n y o u r p referred i n put
method o r key b o a rd l ayout.
O n ce more t h a n o n e i n p u t method is confi g u re d , the u s e r c a n switch betwee n them q u ic k l y by
typ i n g Supe r +Space (so metimes ca l l ed Windows+Space). A status indicator w i l l a l so a p pe a r
i n t h e G N O M E top b a r, w h i c h has t w o f u n c t i o n s : I t i n d icates w h i c h i n put m e t h o d is a ct i ve, a n d
a c t s a s a m e n u t h a t c a n be u s e d to s w i t c h betwee n i n put m e t h o d s o r s e l ect a d va n ce d featu res of
more co m p l ex i n put methods.
Some of t h e m e t h o d s a re m a rked w i t h g e a rs, which i n d icate t h a t those m e t h o d s have a d va nced
confi g u ra t i o n options and c a p a b i l it ies. Fo r exa m p l e, the J a pa nese Ja p a n e s e (Ka n a Ka nji) i n put
method a l l ows the user to p re-edit text i n Lat i n and u s e Down A r r ow and U p A r r ow keys to
sel ect the correct c h a racters to use.

2:5�

US E n g l i s h s p e a kers may f i n d a l s o t h i s u s ef u l . Fo r exa m p l e, u n d e r E n g l i s h (United States) i s t h e
keyboard layout E n g l i s h (i n t e r n at i o n a l A l t Gr d e a d keys), w h i c h t r e a t s A l t G r ( o r t h e r i g h t Alt )
on a P C 1 04/1 0 5-key key b o a rd as a "seco n d a ry-s h ift " m o d i f i e r key a n d d e a d k e y act ivati o n key
for ty p i n g a d d i t i o n a l c h a racters. There a re a l so Dvora k a n d ot h e r a l te r n ative l ayouts ava i l a b l e.

�-

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Note
Any U n i code c h a racter can be entered i n t h e G N O M E d es ktop e n v i ro n m e nt if t h e u s e r
knows t h e c h a racter's U n icode code point, by t y p i n g Ct r l+ S h if t + U , fol l owed by t h e
cod e poi nt. After C t r l+Shif t + U h a s b e e n typ e d , a n u n d e r l i ned u w i l l b e d i s p l ayed t o
i n d icate t h a t t h e system i s wa i t i n g for U n ic o d e code p o i n t ent ry.
For exa m p l e, t h e l owercase Greek l etter l a m bd a h a s t h e code p o i n t U + 0 3 B B, a n d c a n b e
entered by typi n g C t r l+Shift + U , t h e n 03bb, t h e n E n t e r .

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System-wide default language settings
T h e syste m ' s defa u lt l a n g u a g e is set to U S E n g l i s h , u s i n g t h e U T F-8 encod i n g of U n icode as its
c h a racter set (e n_US . u t f8), but t h i s can be c h a n g e d d u r i n g o r after i nsta l l at i o n .
Fro m t h e co m m a n d l i n e, root can c h a n g e t h e syste m-wide l o c a l e sett i n g s w i t h t h e locale c t l
co m m a n d . I f localec t l i s r u n with n o a rg u m e nts, it w i l l d i s p l ay t h e c u rrent syste m - w i d e l o ca l e
sett i n g s.

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L a n g u a g e packs
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To set t h e syste m-wide l a n g u a g e , run t h e co m m a n d localec t l s e t - locale LANG=1oca1e,

w h e re locale i s t h e a p p ropriate $ LANG from t h e " L a n g u a g e Codes Refe re nce" ta b l e
i n t h i s c h a pt e r. T h e c h a n g e w i l l ta ke effect f o r u s e rs o n t h e i r next l o g i n , a n d is stored i n
/ e t c / locale . cont.

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[ root@host -]#

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localectl set - locale LANG=f r_FR . u tf8

In G N O M E, an a d m i n istrative u s e r ca n c h a n g e t h i s sett i n g from R e g i o n & L a n g u a g e a n d c l i c k i n g
t h e L o g i n Screen button at t h e u p per-right c o r n e r o f t h e w i n d ow. C h a n g i n g t h e L a n g u a g e
of t h e l o g i n s c reen w i l l a l so a dj u st t h e syste m-wide defa u lt l a n g u a g e sett i n g sto red i n t h e
/ e t c/locale . c o n f confi g u ra t i o n f i l e .

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Important

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Loca l text consoles s u c h a s t ty2 a re m o re l i m ited i n t h e fo nts t h a t t h ey c a n d i s p l ay
t h a n gnome - t e rminal a n d s s h sess i o n s. For exa m p l e, J a p a n ese, Kore a n , a n d C h i nese
c h a racters may not d is p l ay a s ex pected o n a loca l text conso l e. Fo r t h is reas o n , it may
m a ke sense to u s e E n g l i s h o r a n ot h e r l a n g u a g e w i t h a L a t i n c h a racter set for the
syste m ' s text conso l e.

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L i kewise, l o c a l text c o n s o l e s a re m o re l i m ited i n t h e i n p u t m e t h o d s t h ey s u p p o rt, a n d
t h i s i s m a n a g e d s e p a rate l y from t h e g ra p h ic a l d e s ktop e n v i ro n m e nt. T h e ava i l a b l e
g l o b a l i n put sett i n g s c a n b e config u red t h ro u g h locale c t l f o r both loca l text v i rt u a l
c o n s o l e s a n d t h e X11 g ra ph i ca l e n v i ro n m e nt. S e e t h e localec t l(1), kbd(4), a n d
vconsole . conf(5) m a n pages f o r m o re i nform a t i o n .

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Language packs

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W h e n u s i n g n o n - E n g l i s h l a n g u a g es, you may want to i n sta l l a d d i t i o n a l " l a ng u a g e packs" to
p rovide a d d i t i o n a l t ra n s l at i o n s , d i c t i o n a ries, a n d so fort h . To v i ew t h e l i st of ava i l a b l e l a n g pa c ks,
run yum langavailable. To view the l ist of l a n g pa c ks c u r r e n t l y i n sta l l e d on the system,
r u n yum langlis t . To a d d a n a d d i t i o n a l l a n g pa c k to t h e syste m , r u n yum lan g i n s t all
code, w h e re code i s the code in s q u a re brac kets afte r the l a n g u a g e n a m e i n the o u t p u t of yum
langavailable.

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References
locale(7), localec tl(1), kbd (4), locale . conf(5), vconsole . conf(5),
u nicode(7 ) , u t f - 8(7), and yum - langpacks(8) man pages
Conversions betwee n the n a m e s of t h e g ra p h i c a l d e s kt o p e n v i ro n m e nt ' s
X11 l ayouts a n d t h e i r n a m es i n locale c t l can b e fo u n d i n t h e fi l e
/ u s r / s ha re/X11/xkb/ r u le s / base . ls t .

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Language Codes Reference
-

Language Codes
Lanquaqe

$LANG value

E n g l i s h ( U S)

e n_ U S.utf8

Assamese

as_I N . utf8

Benga l i

bn_IN. utf8

C h i n ese (S i m p l ified)

zh_C N . utf8

C h i n ese ( Tra d i t i o n a l )

z h_TW. utf8

Fre n c h

f r_FR.utf8

German

de_D E.utf8

G uj a rati

g u_I N .utf8

Hindi

h i_I N . u tf8

Ita l i a n

it_ I T.utf8

J a pa nese

j a_J P.utf8

Kannada

k n_ I N .utf8

Kore a n

ko_K R.utf8

M a l aya l a m

m l_I N .utf8

M a ra t h i

m r_I N .utf8

Odia

o r_IN . utf8

Port u g u ese ( B ra z i l i a n)

pt_B R.utf8

P u nj a b i

pa_I N . utf8

Russian

r u_R U .utf8

Spanish

es_ES.utf8

Ta m i l

ta_IN.utf8

Te l u g u

te_IN .utf8

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TRAINING

C H A PT E R 1

ACCESSING THE COMMAND
LINE

Overview

Goal

To log i n t o a Lin u x system a n d r u n s i m p l e c o m m a nds u s i n g
the shell.

Objectives

•

Use B a s h s h e l l syntax to enter c o m m a nds at a L i n ux
console.

•

•

L a u n c h a p p l i ca t i o n s i n a G N O M E desktop e n v i ro n me nt.
Use Bash features to run c o m m a nds from a s h e l l p ro m pt
u s i n g fewer keystrokes.

Sections

•

Acces s i n g t h e C o m m a nd Line U s i n g t h e Loc a l Console
(a nd P ra c t i ce)

•

Acces s i n g the C o m m a nd Line U s i n g the Desktop (a nd
Practice)

Lab

R H 1 24- R H E L7-en-1 -20140606

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Exec u t i n g C o m m a nds U s i n g t h e Bash S h e l l (and Pract ice)

•

Acces s i n g t h e C o m m a nd L i ne


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C h a pte r 1 . Acces s i n g t h e C o m m a n d L i n e
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Access i n g t h e Co m m a n d L i n e U s i n g t h e Loca l
Conso l e

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Objectives
After com p l et i n g t h i s sect i o n , students s h o u l d be a b l e to l o g i nto a L i n u x system on a loca l text
console a n d run s i m p l e co m m a n d s u s i n g the s h e l l .

The bash shell

-

A command line i s a text-based i nt e rface which c a n b e used to i n put i n st r u c t i o n s to a com puter
syste m. The L i n u x co m m a n d line i s p rovided by a p ro g ra m c a l l e d t h e shell. Over t h e long h i story
of U N IX - l i ke syste ms, m a ny s h e l l s have been deve l o pe d . The defa u lt s h e l l for u s e rs in Red H a t
E n t e r p r i s e L i n u x is t h e G N U Bourn e-Ag a i n S h e l l (bash). B a s h is a n i m p roved vers i o n of o n e o f
t h e m ost s u ccess f u l s h e l l s used o n U N I X- l i ke syste m s , t h e B o u r n e S h e l l ( s h ) .
W h e n a s h e l l i s used i nteractive l y, it d i s p l ays a stri n g w h e n it i s wa iting for a c o m m a n d from t h e
user. This is ca l l ed t h e shell prompt. W h e n a reg u l a r u s e r s t a r t s a s h e l l , t h e defa u lt p ro m pt e n d s
with a $ c h a racter.

[ student@desktopX -]$

r-

l

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T h e $ i s re p l a ced b y a # i f t h e sh e l l is r u n n i n g a s t h e s u pe r u s e r, root. T h i s m a kes it m o re obvious
t h a t it is a s u pe r u s e r s h e l l , which h e l ps to avo i d a c c i d e nts and m i sta kes i n t h e priv i l eg e d a ccou nt.

[ root@desktopX -]#

-

� - �����

I
i
I

L>=-SJ

-

U s i n g bash to execute co m m a n d s c a n be powerf u l . T h e bash s h e l l prov ides a s c r i pt i n g l a n g u a g e
t h a t can s u p port a ut o m a t i o n o f tas ks. The s h e l l h a s a d d i t i o n a l ca pa b i l ities t h a t c a n s i m p l ify o r
m a ke poss i b l e o p e rat i o n s t h a t a re h a rd to acco m p l i s h eff i c i e n t l y w i t h g ra p h i c a l too l s .

-�>,

Note

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The bash s h e l l is s i m i l a r i n concept to t h e com m a n d l i n e interpreter fou n d i n recent
vers i o n s of M ic rosoft W i n d ows cmd . exe, a l t h o u g h bash h a s a m o re s o p h isticated
scri pti n g l a n g u a g e. It i s a l so s i m i l a r to W i n d ows Powe r S h e l l i n W i n d ows 7 and W i n dows
Server 2008 R2. Mac O S X a d m i n ist rators who u s e the M a c i ntos h ' s Te r m i n a l u t i l ity
may b e p l eased to note that bash is the d e fa u l t s h e l l in Mac OS X.

Virtual consoles

-

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Users access t h e bash s h e l l t h ro u g h a terminal. A t e r m i n a l provides a key boa rd for u s e r i n put
a n d a d i s p l a y for output. O n text-based i n sta l l a t i o n s , this c a n b e t h e L i n u x m a c h i n e ' s physical
console, t h e h a rdware key b o a rd a n d d i s p l ay. Te r m i n a l access c a n a l so be config u red t h ro u g h
seria l ports.

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Another way to a ccess a s h e l l is from a virtual console. A L i n u x m a c h i n e ' s phys i c a l conso l e
s u p po rts m u l t i p l e v i rt u a l consoles w h i c h act l i ke s e p a rate term i n a l s. Each v i rt u a l co n s o l e

s u p po rts a n i n d e p e n d e n t l o g i n sess i o n .
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Shel l basics
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I f t h e g ra p h i c a l en vi ro n m e n t i s ava i l a b l e, it w i l l r u n on t h e first v i rt u a l conso l e i n Red H a t
E n te r p r i s e L i n u x 7. Five a d d i t i o n a l t e x t l o g i n p ro m pts a re a va i l a b l e o n conso l es t w o t h ro u g h s i x
(or o n e t h ro u g h f i v e if t h e g ra p h ica l e n v i ro n m e nt i s t u r n e d off). With a g ra p h ica l e n v i ro n m e n t
r u n n i n g , access a text l o g i n pro m pt o n a v i r t u a l conso l e by h o l d i ng Ct r l +Alt a n d p ress i n g a
f u n c t i o n key (F2 t h ro u g h F6). Press C t r l +Al t + F l to ret u r n to t h e fi rst virtua l conso l e a n d t h e
g ra p h i c a l d e s ktop.

Important

-

I n t h e p re-config u re d v i rt u a l i m a g es d e l ivered by Red H a t , l o g i n p ro m pts have b e e n
d i sa b l ed i n t h e v i rt u a l co n s o l es .

-

-

Note
I n Red H a t Enterprise L i n u x 5 a n d ea r l i e r, t h e f i rst six v i r t u a l c o n s o l e s a l ways p rovided
text login prom pts. When the g ra p h i ca l e n v i ro n m e nt was l a u n c h e d , it ran o n v i rt u a l
c o n s o l e seven (accessed t h ro u g h Ct r l +Al t + F 7 ) .

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Shell basics
C o m m a n d s entered at t h e s h e l l p ro m pt have t h ree basic pa rts:
Command to run
•

-

•

Options to adjust the b e h a v i o r of t h e com m a n d

•

Arguments, w h i c h a re typica l l y t a rg ets o f t h e co m m a n d

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-

T h e command is t h e n a m e o f t h e p ro g ra m t o r u n . I t may b e fo l l owed by o n e or m o re options,
w h i c h a dj u st t h e behavior of t h e c o m m a n d or w h a t it w i l l d o. O pt i o n s n o rm a l l y sta rt w i t h o n e o r
t w o d a s hes ( - a o r - - all, for exa m p l e) to d i st i n g u i s h t h e m from a rg u ments. Com m a n d s may a l so
b e fo l l owed by one or m o re arguments, w h i c h often i n d icate a t a rg et t h a t t h e co m m a n d s h o u l d
o p e rate o n .

-

-

-

Fo r exa m p l e, t h e com m a n d l i n e u s e r mod - L mo r gan h a s a com m a n d ( use rmod), a n option
( - L), and a n a rg u m e n t (mo r g an ) . T h e effect of t h i s com m a n d i s to l o c k t h e passwo rd o n user
m o rg a n ' s a ccount.
To u s e a com m a n d effect i ve l y, a user needs to k n ow w h a t options and a rg u ments it ta kes a n d
i n w h a t o rd e r i t expects t h e m (t h e syntax o f t h e com m a n d). M ost c o m m a n d s have a - - help
option. This causes t h e com m a n d to print a description of what it does, a " u sage state m e n t " t h a t
d e s c r i b e s t h e co m m a n d ' s sy n t a x , a n d a l i st o f t h e opt i o n s it a ccepts a n d w h at t hey d o .

-

U s a g e statements m a y seem c o m p l icated a n d d i ff i c u l t to rea d . T h e y b e c o m e m u c h s i m p l e r t o
u n d e rsta n d once a user beco m e s fa m i l i a r w i t h a few b a s i c convent i o n s :
-

•

S q u a re b ra c kets, [ ] , s u rro u n d o pt i o n a l ite m s .

•

Anyt h i n g fol lowed by ... represents a n a r b it ra ry- l e n g t h l i st o f items o f t h a t type.

•

M u lt i p l e items sepa rated by p i pes,

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I. m e a n s o n l y one of t h e m ca n b e specified.

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C h a pte r 1 . Access i n g t h e C o m m a n d L i n e
•

Text i n a n g l e b ra c kets, < > , represe n t s va r i a b l e data. Fo r exa m p l e, <filename> m e a n s " i n s e rt
t h e f i l e n a m e you w i s h to u s e h e re". S o m et i m es these va ria b l es a re s i m p l y written i n c a p ita l
l etters (e.g., F I L E N A M E).

C o n s i d e r t h e f i rst usage state m e n t for t h e da t e co m m a n d :

[student@desktopX -]$ date
date [OPTION] . . . [+FORMAT]

r·�
!

I

-

-

- - h elp

-

T h i s i n d icates t h a t d at e c a n take a n o pt i o n a l l i st of o p t i o n s ( [OPTION] . . . ), fo l l owed by a n
o pt i o n a l fo r m a t stri n g , prefixed w i t h a p l u s c h a racter, +, t h a t defines how t h e c u rrent date s h o u l d
b e d i s p l ayed ( [+FORMAT]). S i n ce b o t h o f these a re option a l , d a t e wi l l w o r k even if it i s n o t g i v e n
o p t i o n s o r a rg u me nts (it w i l l p r i n t t h e c u rrent date a n d t i m e u s i n g i t s defa u lt form at).

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Note
T h e man page for a com m a n d h a s a SY N O P S I S sect i o n t h a t p rovi d e s i nfor m a t i o n a b o u t
t h e co m ma n d ' s s y n t a x . T h e man - pages(7) m a n pa g e d e s c r i b e s how to interpret a l l
t h e s q u a re b rac kets, vertica l ba rs, a n d s o forth t h at u s e rs see i n SY N O PS I S o r a u s a g e
message.

W h e n a u s e r is f i n ished u s i n g t h e s h e l l a n d wa nts to q u it. t h e re a re a c o u p l e of ways to e n d t h e
s e s s i o n . T h e e x i t com m a n d ter mi nates t h e c u rrent s h e l l s e s s i o n . A n o t h e r w a y t o f i n i s h a sess i o n
is by typ i n g C t r l+D.

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References

R

in t r o(l), bash(l ) , console(4), p t s (4), a n d man - pages(7) m a n pages

-

Note: Some details of the console(4) man page, involving init(B) and inittab(S), are
outdated.

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Pract ice: Loca l Conso l e Access Te r m s
-

P ra ct i ce: Loca l Conso l e Access Te r m s
-

Quiz

-

-

-

-

M atch t h e fo l l ow i n g item s to t h e i r cou nterparts i n t h e t a b l e.

I
j

A rg u m e nt
P ro m pt

-

jI

18
I
!B I
Command

Shell

Te r m i n a l

Phys i ca l c o n s o l e

Vi r t u a l c o n s o l e

Description
-

-

-

Term

I

T h e i n t e r p rete r t h at exe c u tes co m m a n d s typed
a s st r i n g s.

T h e v i s u a l c u e t h a t i n d i cates a n i nt e ract ive s h e l l
i s wa i t i n g fo r t h e u s e r to type a co m m a n d .

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-

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T h e n a m e o f a p ro g ra m to r u n .

T h e pa rt o f t h e c o m m a n d l i n e t h a t a dj u sts t h e
b e h a v i o r o f a co m m a n d .

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T h e p a rt o f t h e co m m a n d l i n e t h a t s pe c i f i e s t h e
ta rget t h a t t h e co m m a n d s h o u l d o p e rate o n .

T h e h a rd wa re d i s p l a y a n d keyboa rd u s e d t o
i nt e ract w i t h a syst e m .

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O n e of m u lt i p l e l o g i ca l co n s o l es t h a t c a n e a c h
s u p po rt a n i n d e pe n d e n t l og i n sess i o n .

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C h a pte r 1 . Access i n g t h e C o m m a n d L i n e
-

Description

Term

A n inte rfa ce t h a t p rovid es a dis p l a y f o r o u t p u t
a n d a key boa rd fo r in p u t to a s h e l l sessio n.

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-

-

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RH124- R H E L 7 - e n -1-20140606

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Solution
-

Solution
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M atch t h e fo l l owi n g items to t h e i r cou nterparts i n t h e ta b l e.

Description

Term

T h e i nt e r p rete r t h a t executes com m a n ds ty p e d
a s st r i n g s .

Shell

T h e v i s u a l c u e t h a t i n d i cates a n i nt e ra ct ive s h e l l
is wa i t i n g for t h e u s e r to t y p e a co m m a nd .

Prom pt

T h e n a m e of a p rog ra m to r u n .

Co m m a n d

T h e p a rt of t h e c o m m a n d l i n e that a dj u sts t h e
b e h a v i o r of a co m m a n d .

Option

T h e pa rt of t h e c o m m a n d l i n e that s p e c i f i es t h e
ta rg et t h a t t h e c o m m a n d s h o u l d o p e rate o n .

A rg u m e nt

T h e h a rd wa re d i s p l ay a n d keybo a rd u s ed to
i nt e ra ct w i t h a syst e m .

Phys i ca l c o n s o l e

O n e of m u l t i p l e l o g i ca l c o n s o l es t h a t ca n e a c h
s u p p o rt a n i n d e p e n d e n t l og i n sess i o n .

V i rt u a l co n so l e

A n i nte rfa ce t h a t p rov i d es a d i s p l a y for o u t p u t
a n d a key boa rd for i n p u t to a s h e l l sess i o n .

Te r m i n a l

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-

-

-

-

-

-

-

-

·-

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C h a pter 1 . Accessi n g t h e C o m m a n d L i n e
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Access i n g t h e Co m m a n d L i n e U s i n g t h e
D es kt o p

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Objectives
Afte r com p l e t i n g t h i s sect i o n , students s h o u l d be a b l e to l o g i nto t h e L i n u x system u s i n g t h e
G N O M E 3 d es ktop enviro n m e n t to r u n c o m m a n d s f r o m a s h e l l p ro m pt i n a term i n a l p rog ra m .

-

The GNOME desktop environment

-

T h e desktop environment is t h e g ra p h ica l user i nterface on a L i n u x system. T h e defa u l t des ktop
e n v i ro n m e nt i n Red Hat Enterprise L i n u x 7 is provided by G N O M E 3. I t p rovides a n i ntegrated
d e s ktop for users and a u n ified deve l o p m e nt p l a tform o n top of a g ra p h i c a l framework p rovided
by the X W i n d o w System.
T h e GN O M E S h e l l provides the core user i nterface f u n ct i o n s for the G N O M E d esktop
e n v i ro n m e nt. The gnome - s hell a p p l ication i s h i g h l y custo m i z a b l e. By defa u lt, R H E L 7 u s e rs
u s e t h e " G N O M E C l assic" t h e m e for g nome - s hell, w h i c h i s s i m i l a r to t h e G N O M E 2 desktop
e n v i ro n m e nt. A n o t h e r ava i l a b l e o p t i o n i s t h e " m o d e r n " G N O M E 3 theme used by t h e u pstrea m
G N O M E p roj ect. E i t h e r t h e m e c a n b e s e l ected p e rs i ste n t l y at l o g i n by s e l e c t i n g the g e a r i c o n next
to the S i g n I n button when e n t e r i n g t h e user's password.
T h e f i rst time a new u s e r l o g s in, an i n i t i a l set u p program runs to h e l p them config u re b a s i c
acco u nt sett i n gs. The GN O M E He l p a p p l ication i s t h e n sta rted o n t h e Gett i n g Started w i t h
GN O M E screen. This screen i n c l u d e s v i d eos and documentation to help o r i e n t n ew u s e rs to the
G N O M E 3 e n v i ro n ment. GN O M E He l p c a n be q u i c k l y sta rted by t y p i n g F1 i n g nome - shell, by
selecting A p p l i c a t i o n s > D o c u m e n t a t i o n > He l p , o r by r u n n i n g t h e yelp com m a n d .

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The GN O M E desktop e nvi ronment

._ Applications

Ptaces

en2

�») 2

Fri 08:43

Q

Student User

1/4

Figure 1.1: An empty GNOME 3 desktop
Pa rts of t h e G N O M E S h e l l

The v a r i o u s pa rts of t h e GN O M E S h e l l have s p e cific na mes a nd pu r poses. These pa rts inc l u d e t h e
fo l l ow i n g :
top bar: The bar t h a t r u n s a l o ng t h e top of t h e s c r e e n . The top ba r p rovides t h e A p p l icat i o n s
and Places menus, a nd cont ro l s for vo l u m e, netwo rking , c a l e nd a r a ccess, a nd selecting
between keybo a rd input methods (if t h e re are m ore t h a n o n e config u re d ) . U nd e r t h e m e n u for
t h e u s er's nam e are opti ons to a d just a c c o u nt sett i ngs, l o c k t h e screen, switch u sers, log out of

t h e syst e m , o r s h u t it d own.
Applications menu: T h i s menu on t h e t o p ba r p rovides a way to start a p p l ications, categorized

into s u bm enus. T h e Activities Overview c a n a lso be started fro m t h i s m e n u .
Places menu: T h i s menu to t h e r i g ht o f t h e A p p l icat i o n s menu p rov i d e s q u i c k a ccess t h r o u g h
a g ra p h i c a l f i l e m a n a g e r t o i m po rtant m enus i n t h e use r's home d i re cto ry, to I , a nd to exports
and file s h a res o n the n etwork.
window list: The ba r that runs a lo n g t h e bottom of t h e screen. The w i ndow l i st p rovides a n easy

way to a ccess, m i ni m ize, a nd rest o re a l l w i nd ows in t h e c u rrent workspace. On t h e right corne r
is an i nd icator to tell t h e user w h i c h workspace t h ey are on a n d how m a ny a re ava i l a ble.
message tray: The messa g e t ra y p rovides a way to review notifications sent by a p p l icati ons or

system c o m p o ne nts to GN O M E. If a notification occ u rs, no r m a l ly the notification f i rst a p pears
briefly a s a s i n g l e l i ne at t h e bottom of the s c re e n , a nd a persistent i nd i cator a p pe a rs i n the
l ower right c o r n e r to i nform t h e user of how m a ny notifications have bee n recent l y received.

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