OReilly linux in a nutshell 4th edition jun 2003 ISBN 0596004826

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TableofContents
Index
Reviews
ReaderReviews
Errata

LinuxinaNutshell,4thEdition
ByStephenFiggins,EllenSiever,

AaronWeber

Publisher :O'Reilly
PubDate :June2003
ISBN :0-596-00482-6
Pages :944
Slots :1



Comprehensivebutconcise,Linuxina
Nutshellisanessentialdesktopreferencefor
thecommandsthatusersofLinuxutilize
everyday.Itcoversallsubstantialuser,

programming,administration,andnetworking
commandsforthemostcommonLinux
distributions.It'sseveralquickreferences
rolledintoone:sed,gawk,RCS,CVS,vi,
Emacs,bash,tcsh,regularexpressions,
packagemanagement,bootloaders,and


desktopenvironmentsareallcoveredinthis
clear,to-the-pointvolume,alongwithcore
command-lineutilities.



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•
•
•
•


TableofContents
Index
Reviews
ReaderReviews
Errata

LinuxinaNutshell,4thEdition
ByStephenFiggins,EllenSiever,

AaronWeber

Publisher :O'Reilly
PubDate :June2003
ISBN :0-596-00482-6
Pages :944
Slots :1




Copyright

Preface
OtherResources

Conventions




We'dLiketoHearfromYou
Acknowledgments


Chapter1.Introduction
Section1.1.TheExcitementofLinux

Section1.2.DistributionandSupport

Section1.3.CommandsonLinux




Section1.5.SourcesandLicenses

Section1.4.WhatThisBookOffers
Section1.6.Beginner'sGuide


Chapter2.SystemandNetworkAdministrationOverview
Section2.1.CommonCommands

Section2.2.OverviewofNetworking






Section2.3.OverviewofTCP/IP




Section2.5.OverviewofNFS

Section2.7.AdministeringNIS

Section2.4.OverviewofFirewallsandMasquerading
Section2.6.OverviewofNIS
Section2.8.RPCandXDR


Chapter3.LinuxCommands
Section3.1.AlphabeticalSummaryofCommands


Chapter4.BootMethods
Section4.1.TheBootProcess

Section4.2.LILO:TheLinuxLoader




Section4.3.GRUB:TheGrandUnifiedBootloader




Section4.5.Loadlin:BootingfromMS-DOS

Section4.7.Boot-TimeKernelOptions

Section4.4.GRUBCommands
Section4.6.Dual-BootingLinuxandWindowsNT/2000/XP
Section4.8.initrd:UsingaRAMDisk


Chapter5.RedHatandDebianPackageManagers
Section5.1.TheRedHatPackageManager

Section5.2.TheDebianPackageManager


Chapter6.TheLinuxShells:AnOverview
Section6.1.PurposeoftheShell

Section6.2.ShellFlavors




Section6.3.CommonFeatures
Section6.4.DifferingFeatures


Chapter7.bash:TheBourne-AgainShell
Section7.1.InvokingtheShell

Section7.2.Syntax




Section7.3.Variables




Section7.5.CommandHistory



Section7.7.Built-inCommands

Section7.4.ArithmeticExpressions
Section7.6.JobControl


Chapter8.tcsh:AnExtendedCShell
Section8.1.OverviewofFeatures

Section8.2.InvokingtheShell




Section8.3.Syntax

Section8.4.Variables




Section8.5.Expressions




Section8.6.CommandHistory




Section8.8.JobControl

Section8.7.Command-LineManipulation
Section8.9.Built-inCommands


Chapter9.PatternMatching
Section9.1.FilenamesVersusPatterns

Section9.2.Metacharacters,ListedbyLinuxProgram




Section9.3.Metacharacters

Section9.4.ExamplesofSearching


Chapter10.TheEmacsEditor
Section10.1.EmacsConcepts

Section10.2.TypicalProblems




Section10.3.NotesontheTables




Section10.5.SummaryofCommandsbyKey

Section10.4.SummaryofCommandsbyGroup
Section10.6.SummaryofCommandsbyName


Chapter11.TheviEditor
Section11.1.ReviewofviOperations

Section11.2.viCommand-LineOptions

Section11.3.exCommand-LineOptions




Section11.5.EditCommands




Section11.7.AccessingMultipleFiles




Section11.9.InteractingwiththeShell




Section11.11.MiscellaneousCommands




Section11.13.SyntaxofexCommands



Section11.15.viConfiguration

Section11.4.MovementCommands
Section11.6.SavingandExiting
Section11.8.WindowCommands
Section11.10.Macros
Section11.12.AlphabeticalListofKeysinCommandMode
Section11.14.AlphabeticalSummaryofexCommands


Chapter12.ThesedEditor
Section12.1.Command-LineSyntax

Section12.2.SyntaxofsedCommands




Section12.3.GroupSummaryofsedCommands
Section12.4.AlphabeticalSummaryofsedCommands




Chapter13.ThegawkScriptingLanguage




Section13.1.Command-LineSyntax

Section13.3.gawkSystemVariables




Section13.5.Operators




Section13.7.GroupListingofgawkCommands

Section13.2.PatternsandProcedures
Section13.4.PROCINFOArray
Section13.6.VariableandArrayAssignments
Section13.8.AlphabeticalSummaryofCommands


Chapter14.RCS
Section14.1.OverviewofRCSCommands

Section14.2.BasicRCSOperations




Section14.3.GeneralRCSSpecifications

Section14.4.AlphabeticalSummaryofRCSCommands


Chapter15.CVS
Section15.1.BasicConcepts

Section15.2.CVSCommandFormat




Section15.3.CommonGlobalOptions




Section15.5.CVSAdministratorReference

Section15.4.Gotchas
Section15.6.CVSUserReference


Chapter16.GraphicalDesktopOverview
Section16.1.DesktopEnvironmentsandWindowManagers

Section16.2.DesktopDifferences:Development


Chapter17.GNOME
Section17.1.DesktopOverview

Section17.2.ThePanel




Section17.3.TheGNOMEMenuandtheMenuPanelMenus



Section17.5.HistoryandChangesinGNOME2

Section17.4.TheGNOMEControlCenter


Chapter18.KDE
Section18.1.DesktopOverview

Section18.2.ThePanel



Section18.3.TheKDEControlCenter


Chapter19.AnAlternativeWindowManager:fvwm2
Section19.1.Runningfvwm2

Section19.2.ImplementingWindowManagerCustomizations

Section19.3.AddingKeyboardShortcuts




Section19.4.CustomizingMenus



Section19.5.TheWinList:SwitchingtheFocus




Colophon
Index


Copyright©2003,2000,1999,1997O'Reilly&Associates,Inc.
PrintedintheUnitedStatesofAmerica.
PublishedbyO'Reilly&Associates,Inc.,1005Gravenstein
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NutshellHandbook,theNutshellHandbooklogo,andthe

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Inc.Manyofthedesignationsusedbymanufacturersand
sellerstodistinguishtheirproductsareclaimedastrademarks.
Wherethosedesignationsappearinthisbook,andO'Reilly&
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designationshavebeenprintedincapsorinitialcaps.The
associationbetweentheimageofanArabianhorseandthe
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Whileeveryprecautionhasbeentakeninthepreparationofthis
book,thepublisherandauthorsassumenoresponsibilityfor
errorsoromissions,orfordamagesresultingfromtheuseof
theinformationcontainedherein.


Preface
ThisisabookaboutLinux,afreelyavailablecloneoftheUnix
operatingsystemwhoseusesrangefromembeddedsystems
andpersonaldataassistants(PDAs)tocorporateservers,web
servers,andmassiveclustersthatperformsomeoftheworld's
mostdifficultcomputations.
WhetheryouareusingLinuxforpersonalsoftwareprojects,for
asmallofficeorhomeoffice(theso-calledSOHOenvironment),
toprovideservicestoasmallgroupofcolleagues,orto
administerasiteresponsibleformillionsofemailandweb
connectionseachday,youneedquickaccesstoinformationon
awiderangeoftools.Thisbookcoversallaspectsof
administeringandmakingeffectiveuseofLinuxsystems.
Amongitstopicsarebooting,packagemanagement,andthe
configurationoftheGNOMEandKDEdesktops.Butforemostin
LinuxinaNutshellaretheimmeasurableutilitiesand

commandsthatmakeLinuxoneofthemostpowerfuland
flexiblesystemsavailable.
Inadditiontothetoolsandfeatureswrittenspecificallyforit,
LinuxhasinheritedmanyfromtheFreeSoftwareFoundation's
GNUproject,theBerkeleySoftwareDistribution(BSD),theX
WindowSystem(XFree86),andcontributionsfrommajor
corporationsaswellasthecompaniesthatcreatedthemajor
Linuxdistributions.MorerecentprojectsextendLinuxin
excitingways,somethroughchangestothekernelandsome
throughlibrariesandapplicationsthatradicallychangethe
user'sexperience;theGNOMEandKDEdesktopsarethemost
prominentexamples.
Thisbookisaquickreferenceforthebasiccommandsand
featuresoftheLinuxoperatingsystem.Aswithotherbooksin
O'Reilly's"InaNutshell"series,thisbookisgearedtoward
userswhoknowwhattheywanttodoandhavesomeideahow


todoit,butcan'talwaysrememberthecorrectcommandor
option.


OtherResources
Thisbookdoesn'ttellyouhowtoinstallandcomeuptospeed
onaLinuxsystem.Forthat,youwillprobablywantO'Reilly's
LearningRedHatLinux,whichcontainsaLinuxdistributionon
CD-ROMandprovideshelpwithinstallationandconfiguration.
Alternatively,RunningLinuxisanin-depthguidesuitableforall
majordistributions.Fornetworkinginformation,checkoutthe
LinuxNetworkAdministrator'sGuide.Inadditiontotheseand

otherLinuxtitles,O'Reilly'swiderangeofUnix,X,Perl,and
JavatitlesmayalsobeofinteresttotheLinuxuser.

OnlineDocumentation
TheInternetisfullofinformationaboutLinux.Oneofthebest
resourcesistheLinuxDocumentationProjectat
(oroneofthedozensofmirrorsites
aroundtheworld),whichhasnumerousshortguidescalled
HOWTOs,alongwithsomefullmanuals.Foronlineinformation
abouttheGNUutilitiescoveredinthisbook,consult
(alsowidelymirrored).TheFreeSoftware
Foundation,whichisinchargeoftheGNUproject,publishesits
documentationinanumberofhard-copyandonlinebooks
aboutvarioustools.
Eachdistributionmaintainsitsownwebsite,andcontains
documentationforthesoftwareitprovidesaswellasguidesto
maintainingyoursystemunderthatdistribution.

WebSites
Asbefitsahotphenomenon,Linuxisthecentralsubjectof


severalwebsitesandafrequenttopicofdiscussiononothers.
Somesitesofferoriginalcontent;othersjusthavelinksto
articlespostedelsewhereandthreadeddiscussions(whichcan
beausefulservice).AmongthesitesfrequentedbyLinuxusers
are:

LinuxWeeklyNews,asitewithweeklyin-deptharticlesand
frequentnewsupdates

LinuxGazette,asitepublishedmonthlybyLinuxJournal
witharticlesandtipsinmanylanguages

LinuxSecurity,acollectionofsecurity-relatednews

Slashdot,afamousdiscussionlist

LinuxInsider,anewsfeed

LinuxToday,anothernewsfeed

NewsForge,amoregeneralcomputing-relatednewsfeed

LinuxJournalandLinuxMagazine


LinuxJournalandLinuxMagazinearemonthlymagazinesfor
theLinuxcommunity,writtenandpublishedbyanumberof
Linuxactivists.Withbothprinteditionsandwebsites,they
offerarticlesrangingfromnovicequestionsandanswersto
kernelprogramminginternals.LinuxJournal,at
,istheoldermagazineandis
publishedbyS.S.C.Incorporated,.Linux
Magazineisat.

UsenetNewsgroups
MostpeoplecanreceiveUsenetnewsatworkorthroughtheir
ISPs.Whilethiscommunicationstechnologyhaslostgroundin
thepastseveralyearstoweb-basedthreadeddiscussions,itis

stillavaluablesourceofhelpandcommunityconnectionson
manytopics.ThefollowingLinux-relatednewsgroupsare
popular:
comp.os.linux.announce
Amoderatednewsgroupcontainingannouncementsofnew
software,distributions,bugreports,andgoings-oninthe
Linuxcommunity.AllLinuxusersshouldreadthisgroup.
Submissionsmaybemailedto
comp.os.linux.help
Generalquestionsandanswersaboutinstallingorusing
Linux.
comp.os.linux.admin
DiscussionsrelatingtosystemsadministrationunderLinux.
comp.os.linux.development


DiscussionsaboutdevelopingtheLinuxkernelandthe
systemitself.
comp.os.linux.networking
DiscussionsrelatingtonetworkingwithLinux.
comp.os.linux.security
Helpwithfirewalls,securingservers,andothersecurity
issues.
comp.os.linux.x
HelpongettingtheXgraphicalwindowsystemtowork.
ThislistusedtoseesomeofthehighesttrafficofanyLinux
groupbackwhendistributionshadmoretroublesettingup
graphicsautomatically.Thisisnolongerthecase,thanksto
theincreasingsophisticationofautodetectionand
configurationsoftware.

TherearealsoseveralnewsgroupsdevotedtoLinuxin
languagesotherthanEnglish,suchasfr.comp.os.linuxin
Frenchandde.comp.os.linuxinGerman.

OnlineLinuxSupport
Therearemanywaysofobtaininghelponline,wherevolunteers
fromaroundtheworldofferexpertiseandservicestoassist
userswithquestionsandproblems.
ThefreenodeIRCserviceisanInternetrelaychatnetwork
devotedtoso-called"peer-directed"projects,particularlythose
involvingfreesoftware.Someofitschannelsaredesignedto
provideonlineLinuxsupportservices.
Internetrelaychatisanetworkservicethatallowsyoutotalk


interactivelyontheInternettootherusers.IRCnetworks
supportmultiplechannelswheredifferentgroupsofpeopletype
theirthoughts.Whateveryoutypeinachannelisseenbyall
otherusersofthatchannel.
ThereareanumberofactivechannelsonthefreenodeIRC
networkwhereyouwillfindusers24hoursaday,7daysa
weekwhoarewillingandabletohelpyousolveanyLinux
problemsyoumayhave,orjustchat.Youcanusethisservice
byinstallinganIRCclient(somedistributionsinstallthemby
default),connectingtoservernameirc.freenode.org:6667,and
joiningachannelfocusingonLinux,suchas:
#linpeople

Generalhelpanddiscussion.

#debian

HelpforDebiandistribution.

#gentoo

HelpforGentoodistribution.

#redhat

HelpforRedHatdistribution.

#suse

HelpforSuSEdistribution.

Andsoon.Pleasebesuretoreadupontherulesofchat
etiquettebeforechatting.Inparticular,theparticipantsinthese
groupstendtoexpectpeopletoreaddocumentationanddo
someexperimentationbeforeaskingforhelpwithaproblem.

LinuxUserGroups
ManyLinuxUserGroupsaroundtheworldofferdirectsupport
tousers.Typically,LinuxUserGroupsengageinsuchactivities
asinstallationdays,talksandseminars,demonstrationnights,
andpurelysocialevents.LinuxUserGroupsareagreatwayof


meetingotherLinuxusersinyourarea.Thereareanumberof
publishedlistsofLinuxUserGroups.Someofthebetter-known

onesare:
GroupsofLinuxUsersEverywhere:
/>LUGregistry: />

Conventions
Thisdesktopquickreferencefollowscertaintypographic
conventions:
Bold
isusedforcommands,programs,andoptions.Allterms
showninboldaretypedliterally.
Italic
isusedtoshowargumentsandvariablesthatshouldbe
replacedwithuser-suppliedvalues.Italicisalsousedto
indicatefilenamesanddirectoriesandtohighlight
commentsinexamples.
ConstantWidth
isusedtoshowthecontentsoffilesortheoutputfrom
commands.
ConstantWidthBold
isusedinexamplestoshowcommandsorothertextthat
shouldbetypedliterallybytheuser.
ConstantWidthItalic
isusedinexamplestoshowtextthatshouldbereplaced
withuser-suppliedvalues.
%,$
areusedinsomeexamplesasthetcshshellprompt(%)
andastheBourneorbashshellprompt($).


[]

surroundoptionalelementsinadescriptionofsyntax.(The
bracketsthemselvesshouldneverbetyped.)Notethat
manycommandsshowtheargument[files].Ifafilenameis
omitted,standardinput(e.g.,thekeyboard)isassumed.
Endwithanend-of-filecharacter.
EOF
indicatestheend-of-filecharacter(normallyCtrl-D).
|
isusedinsyntaxdescriptionstoseparateitemsforwhich
onlyonealternativemaybechosenatatime.

Thisiconindicatesanote,whichisanimportantasidetoitsnearby
text.

Thisiconindicatesawarning.

Afinalwordaboutsyntax.Inmanycases,thespacebetween
anoptionanditsargumentcanbeomitted.Inothercases,the
spacing(orlackofspacing)mustbefollowedstrictly.For
example,-wn(nointerveningspace)mightbeinterpreted
differentlyfrom-wn.It'simportanttonoticethespacingused
inoptionsyntax.


We'dLiketoHearfromYou
Wehavetestedandverifiedalloftheinformationinthisbook
tothebestofourability,butyoumayfindthatfeatureshave
changed(oreventhatwehavemademistakes!).Pleaseletus
knowaboutanyerrorsyoufind,aswellasyoursuggestionsfor
futureeditions,bywriting:

O'Reilly&Associates,Inc.
1005GravensteinHighwayNorth
Sebastopol,CA95472
(800)998-9938(intheUnitedStatesorCanada)
(707)829-0515(internationalorlocal)
(707)829-0104(fax)
Thereisawebpageforthisbook,whichlistserrata,examples,
oranyadditionalinformation.Youcanaccessthispageat:
/>Tocommentorasktechnicalquestionsaboutthisbook,send
emailto:

Formoreinformationaboutbooks,conferences,Resource
Centers,andtheO'ReillyNetwork,seetheO'Reillywebsiteat:



Acknowledgments
ThisfourtheditionofLinuxinaNutshellistheresultofthe
cooperativeeffortsofmanypeople.ThankstoAndyOramfor
hiseditorialskills,aswellasforpitchingintocheckexisting
chaptersandupdateandwritenewmaterialasneeded.
Fortechnicalreview,thanksgotoMattWelshofRunningLinux
andInstallationandGettingStartedGuidefame,MichaelK.
JohnsonofRedHatSoftware,RobertJ.Chassell,PhilHughesof
LinuxJournal,LaurieLynneTucker,ArnoldRobbins,JulianT.J.
Midgley,MatthiasKalleDalheimer,TerryDawson,DougMoreen,
RonPasserini,andMarkStone.


Chapter1.Introduction

ItishardtocharttheriseofLinuxoveritstwelveyearsof
existencewithoutriskingtheappearanceofexaggerationand
hyperbole.Duringthepastfiveyearsalone,Linuxhasgrown
fromastudent/hackerplaygroundtoanupstartchallengerin
theservermarkettoawell-respectedsystemtakingitsrightful
placeineducationalandcorporatenetworks.Manyserious
analystsclaimthatitstrajectoryhasjustbegun,andthatitwill
eventuallybecometheworld'smostwidespreadoperating
system.
LinuxwasfirstdevelopedbyLinusTorvaldsattheUniversityof
HelsinkiinFinland.FromhiscurrentlocationinSiliconValley,
Linuscontinuestocentrallycoordinateimprovements.The
Linuxkernelcontinuestodevelopunderthededicated
cultivationofahostofotherprogrammersandhackersallover
theworld,joinedbymembersofprogrammingteamsatmajor
computercompanies,allconnectedthroughtheInternet.
By"kernel,"wemeanthecoreoftheoperatingsystemitself,
nottheapplications(suchasthecompiler,shells,andsoforth)
thatrunonit.Today,theterm"Linux"isoftenusedtomeana
softwareenvironmentwithaLinuxkernelalongwithalargeset
ofapplicationsandothersoftwarecomponents.Inthislarger
meaning,manypeoplepreferthetermGNU/Linux,which
acknowledgesthecentralroleplayedbytoolsfromtheFree
SoftwareFoundation'sGNUprojectinthedevelopmentofthe
kernel.
Linuxsystemscannotbetechnicallyreferredtoasa"versionof
Unix,"astheyhavenotundergonetherequiredtestsand
licensing.[1]However,Linuxoffersallthecommonprogramming
interfacesofstandardUnixsystems,andasyoucanseefrom
thisbook,allthecommonUnixutilitieshavebeen

reimplementedonLinux.Itisapowerful,robust,fullyusable


systemforthosewholikeUnix.
[1]Beforeanoperatingsystemcanbecalled"Unix,"itmustbebrandedbyTheOpenGroup.

ThehistoricalimpactofLinuxgoesbeyonditsroleasa
challengetoallversionsofUnixaswellasMicrosoftWindows,
particularlyonservers.Linux'ssuccesshasalsoinspired
countlessotherfreesoftwareoropensource(definedat
)projects,includingSamba,GNOME,and
amind-bogglingcollectionofinnovativeprojectsthatyoucan
browseatnumeroussiteslikeSourceForge
().Asbothaplatformforother
developersandadevelopmentmodel,Linuxgaveatremendous
boosttotheGNUproject,andhasalsobecomeapopular
platformforJavadevelopment.Inshort,Linuxisacentral
participantinthemostexcitingandproductivefreesoftware
movementeverseen.
Ifyouhaven'tobtainedLinuxyet,orhaveitbutdon'tknow
exactlyhowtogetstartedusingit,seeOtherResourcesinthe
preface.


1.1TheExcitementofLinux
Linuxis,firstofall,freesoftware:anyonecandownloadthe
sourcefromtheInternetorbuyitonalow-costCD-ROM.But
Linuxisbecomingwellknownbecauseit'smorethanfree
softwareit'sunusuallygoodsoftware.Youcangetmorefrom
yourhardwarewithLinuxandbeassuredoffewercrashes;

evenitssecurityisbetterthanmanycommercialalternatives.
Linuxfirstappearedinorganizationsasadhocinstallationsby
hackersrunningmodestwebserversordevelopmentsystems
atuniversitiesandresearchinstitutions,butnowextends
deeplyintocorporationsaroundtheworld.Peopledeploying
Linuxformission-criticalsystemstendtotalkaboutitsample
practicaladvantages,suchastheabilitytodeliveralotofbang
forthebuckandtheeaseofdeployingotherpowerfultoolson
LinuxsuchasApache,Samba,andJavaenvironments.They
alsociteLinux'sabilitytogrowandsproutnewfeaturesof
interesttolargenumbersofusers.Buttheseadvantagescanbe
tracedbacktotheconceptofsoftwarefreedom,whichisthe
rootofthebroadwaveofinnovationdrivingLinux.
Asfreesoftware,Linuxrevivesthegrandcreativityandthe
communityofsharingthatUnixwaslongknownfor.The
unprecedentedflexibilityandopennessofUnixwhichnewcomers
usuallyfoundconfusingandfrustrating,buteventuallyfound
theycouldn'tlivewithoutcontinuallyinspiredextensions,new
toolslikePerl,andexperimentsincomputersciencethat
sometimesendedupinmainstreamcommercialcomputer
systems.
ManyprogrammersfondlyrememberthedayswhenAT&T
provideduniversitieswithUnixsourcecodeatnocharge,and
theUniversityofBerkeleystarteddistributingitsversioninany
mannerthatallowedpeopletogetit.Fortheseolderhackers,
Linuxbringsbackthespiritofworkingtogetherallthemoreso


becausetheInternetisnowsowidespread.Andforthemany
whoaretooyoungtorememberthefirstroundofopensystems

orwhosepriorexperiencehasbeenconstrictedbytryingto
exploreandadaptproprietaryoperatingsystems,nowisthe
timetodiscoverthewondersoffreelydistributablesourcecode
andinfinitelyadaptableinterfaces.
TheeconomicpowerbehindLinux'spopularityisitssupportfor
anenormousrangeofhardware.Peoplewhoareaccustomedto
MS-DOSandMicrosoftWindowsareoftenamazedathowmuch
fastertheirhardwareappearstoworkwithLinuxitmakes
efficientuseofitsresources.
Forthefirstseveralyears,userswereattractedtoLinuxfora
varietyoffinancialandpoliticalreasons,butsoonthey
discoveredanunexpectedbenefit:Linuxworksbetterthan
manycommercialsystems.WiththeSambafileandprint
server,forinstance,Linuxservesalargenumberofend-user
PCswithoutcrashing.WiththeApachewebserver,itprovides
moreoftheusefulfeatureswebadministratorswantthan
competingproductsdo.EmbeddedversionsoftheLinuxkernel
areingrowingusebecause,althoughtheyarelargerthanthe
moststripped-downoperatingsystems,theydeliverarangeof
powerfulfeatureswithinaremarkablysmallfootprint.
OpinionsstilldifferonhowsuitableLinuxisasageneralpurposedesktopsystem.Butthetremendousadvancesin
usabilityandstabilityofthedesktopsoftwareandits
applicationsareundisputed.Soon(ifnottoday),onewillfind
Linuxinmanyofficesandotherend-userenvironments.
Meanwhile,thestridesmadebyLinuxineverydaycomputing
tasksarereflectedinthenewaudioandCD-relatedcommands
foundinthisedition.


1.2DistributionandSupport

Whileitisconvenienttodownloadoneortwonewprograms
overtheInternetandfairlyfeasibletodownloadsomethingas
largeastheLinuxkernel,gettinganentireworkingsystemover
theInternetisdifficultwithoutahigh-speedInternet
connection.Overtheyears,therefore,commercialand
noncommercialpackagescalleddistributionshaveemerged.
Thefirstdistributionconsistedofapproximately50diskettes,at
leastoneofwhichwouldusuallyturnouttobebadandhaveto
bereplaced.WhenCD-ROMdrivesbecamewidespread,Linux
reallytookoff.
AftergettingLinux,theaverageuserisconcernednextwith
support.WhileUsenetnewsgroupsofferveryquickresponses
andmeettheneedsofmanyintrepidusers,youcanalsobuy
supportfromthevendorsofthemajordistributionsanda
numberofindependentexperts.Linuxissupportedatleastas
wellascommercialsoftware.Whenyoubuyadistributionfrom
avendor,youtypicallyareentitledtoaperiodoffreesupportas
well.
Intel'sx86familyandothercompatiblechipsarestillbyfarthe
mostcommonhardwarerunningLinux,butLinuxisalsonow
commerciallyavailableonanumberofotherhardwaresystems,
notablythePowerPC,the64-bitIntelItaniumprocessor,Sun
Microsystems'SPARC,andtheAlpha(createdbyDigital
EquipmentCorporation).