Addison wesley the ruby way solutions and techniques in ruby programming 2nd edition nov 2006 ISBN 0672328844 (1)

TheRubyWay:SolutionsandTechniquesinRuby
Programming,SecondEdition
ByHalFulton
...............................................
Publisher:AddisonWesleyProfessional
PubDate:October25,2006
PrintISBN-10:0-672-32884-4
PrintISBN-13:978-0-672-32884-8
Pages:888

TableofContents|Index

Rubyisanagileobject-orientedlanguage,borrowingsomeofthebestfeaturesfromLISP,
Smalltalk,Perl,CLU,andotherlanguages.Itspopularityhasgrowntremendouslyinthe
fiveyearssincethefirsteditionofthisbook.
TheRubyWaytakesa"how-to"approachtoRubyprogrammingwiththebulkofthe
materialconsistingofmorethan400examplesarrangedbytopic.Eachexampleanswers
thequestion"HowdoIdothisinRuby?"Workingalongwiththeauthor,youarepresented
withthetaskdescriptionandadiscussionofthetechnicalconstraints.Thisisfollowedbya
step-by-steppresentationofonegoodsolution.Alongtheway,theauthorprovides
detailedcommentaryandexplanationstoaidyourunderstanding.
Coverageincludes
•AnoverviewofRuby,explainingterminologyandbasicprinciples
•Operationsonlow-leveldatatypes(numbers,strings,regularexpressions,dates)
•Thenewregularexpressionengine(Oniguruma)
•Internationalization(I18N)andmessagecatalogsinRuby
•Operationsonhashes,arrays,andotherdatastructuressuchasstacks,trees,and
graphs
•WorkingwithgeneralI/O,files,andpersistentobjects
•DatabasecoverageincludingMySQL,SQLite,Oracle,DBI,andmore
•Ruby-specifictechniquesinOOPanddynamicprogramming

•GraphicalinterfacesinRuby(Tk,GTK+,Fox,andQt)
•WorkingwithRubythreadsforlightweightmultitasking


•EverydayscriptingandsystemadministrationinRuby
•Workingwithimagefiles,PDFs,YAML,XML,RSS,andAtom
•Testing,debugging,profiling,andpackagingRubycode
•Low-levelnetworkprogrammingandclient-serverinteraction
•WebdevelopmenttoolsincludingRails,Nitro,Wee,IOWA,andmore
•WorkingwithdistributedRuby,Rinda,andRing
•RubydevelopmenttoolssuchasIDEs,documentationtools,andmore
Thesourcecodeforthebookcanbedownloadedfromwww.rubyhacker.com
HalFultonhasworkedforover15yearswithvariousformsofUnix,includingAIX,Solaris,
andLinux.HewasfirstexposedtoRubyin1999,andin2001hebeganworkonthefirst
editionofthisbookthesecondRubybookpublishedintheEnglishlanguage.Hehas
attendednumerousRubyconferencesandhasgivenpresentationsatseveralofthose,
includingthefirstEuropeanRubyConference.
HehastwodegreesincomputersciencefromtheUniversityofMississippiandtaught
computerscienceforfouryearsbeforemovingtoAustin,Texastoworkasacontractorfor
variouscompanies,includingIBMAustin.HalcurrentlyworksatBroadwing
CommunicationsinAustin,Texas,maintainingalargedatawarehouseandrelatedtelecom
applications,workingdailywithC++,Oracle,and,ofcourse,Ruby.


TheRubyWay:SolutionsandTechniquesinRuby
Programming,SecondEdition
ByHalFulton
...............................................
Publisher:AddisonWesleyProfessional
PubDate:October25,2006

PrintISBN-10:0-672-32884-4
PrintISBN-13:978-0-672-32884-8
Pages:888

TableofContents|Index

Copyright

Foreword
Acknowledgments
AbouttheAuthor
Introduction
Chapter1.RubyinReview
Section1.1.AnIntroductiontoObjectOrientation
Section1.2.BasicRubySyntaxandSemantics
Section1.3.OOPinRuby
Section1.4.DynamicAspectsofRuby
Section1.5.TrainingYourIntuition:ThingstoRemember
Section1.6.RubyJargonandSlang
Section1.7.Conclusion
Chapter2.WorkingwithStrings
Section2.1.RepresentingOrdinaryStrings

Section2.2.RepresentingStringswithAlternateNotations
Section2.3.UsingHere-Documents
Section2.4.FindingtheLengthofaString
Section2.5.ProcessingaLineataTime
Section2.6.ProcessingaByteataTime
Section2.7.PerformingSpecializedStringComparisons

Section2.8.TokenizingaString
Section2.9.FormattingaString
Section2.10.UsingStringsAsIOObjects
Section2.11.ControllingUppercaseandLowercase

Section2.12.AccessingandAssigningSubstrings
Section2.13.SubstitutinginStrings
Section2.14.SearchingaString
Section2.15.ConvertingBetweenCharactersandASCIICodes
Section2.16.ImplicitandExplicitConversion
Section2.17.AppendinganItemOntoaString
Section2.18.RemovingTrailingNewlinesandOtherCharacters
Section2.19.TrimmingWhitespacefromaString
Section2.20.RepeatingStrings
Section2.21.EmbeddingExpressionsWithinStrings
Section2.22.DelayedInterpolationofStrings
Section2.23.ParsingComma-SeparatedData
Section2.24.ConvertingStringstoNumbers(DecimalandOtherwise)
Section2.25.EncodingandDecodingrot13Text
Section2.26.EncryptingStrings
Section2.27.CompressingStrings
Section2.28.CountingCharactersinStrings
Section2.29.ReversingaString
Section2.30.RemovingDuplicateCharacters
Section2.31.RemovingSpecificCharacters
Section2.32.PrintingSpecialCharacters
Section2.33.GeneratingSuccessiveStrings
Section2.34.Calculatinga32-BitCRC
Section2.35.CalculatingtheMD5HashofaString
Section2.36.CalculatingtheLevenshteinDistanceBetweenTwoStrings
Section2.37.EncodingandDecodingbase64Strings
Section2.38.EncodingandDecodingStrings(uuencode/uudecode)
Section2.39.ExpandingandCompressingTabCharacters
Section2.40.WrappingLinesofText
Section2.41.Conclusion

Chapter3.WorkingwithRegularExpressions
Section3.1.RegularExpressionSyntax
Section3.2.CompilingRegularExpressions
Section3.3.EscapingSpecialCharacters
Section3.4.UsingAnchors

Section3.5.UsingQuantifiers
Section3.6.PositiveandNegativeLookahead
Section3.7.AccessingBackreferences
Section3.8.UsingCharacterClasses
Section3.9.ExtendedRegularExpressions
Section3.10.MatchingaNewlinewithaDot

Section3.11.UsingEmbeddedOptions
Section3.12.UsingEmbeddedSubexpressions
Section3.13.RubyandOniguruma
Section3.14.AFewSampleRegularExpressions
Section3.15.Conclusion
Chapter4.InternationalizationinRuby
Section4.1.BackgroundandTerminology
Section4.2.CodinginaPost-ASCIIWorld
Section4.3.UsingMessageCatalogs
Section4.4.Conclusion
Chapter5.PerformingNumericalCalculations
Section5.1.RepresentingNumbersinRuby
Section5.2.BasicOperationsonNumbers
Section5.3.RoundingFloatingPointValues
Section5.4.ComparingFloatingPointNumbers
Section5.5.FormattingNumbersforOutput
Section5.6.FormattingNumberswithCommas
Section5.7.WorkingwithVeryLargeIntegers
Section5.8.UsingBigDecimal
Section5.9.WorkingwithRationalValues
Section5.10.MatrixManipulation
Section5.11.WorkingwithComplexNumbers
Section5.12.Usingmathn
Section5.13.FindingPrimeFactorization,GCD,andLCM
Section5.14.WorkingwithPrimeNumbers
Section5.15.ImplicitandExplicitNumericConversion
Section5.16.CoercingNumericValues
Section5.17.PerformingBit-levelOperationsonNumbers
Section5.18.PerformingBaseConversions
Section5.19.FindingCubeRoots,FourthRoots,andsoon

Section5.20.DeterminingtheArchitecture'sByteOrder
Section5.21.NumericalComputationofaDefiniteIntegral
Section5.22.TrigonometryinDegrees,Radians,andGrads

Section5.23.MoreAdvancedTrigonometry
Section5.24.FindingLogarithmswithArbitraryBases
Section5.25.FindingtheMean,Median,andModeofaDataSet
Section5.26.VarianceandStandardDeviation
Section5.27.FindingaCorrelationCoefficient
Section5.28.GeneratingRandomNumbers
Section5.29.CachingFunctionswithmemoize
Section5.30.Conclusion
Chapter6.SymbolsandRanges

Section6.1.Symbols
Section6.2.Ranges
Section6.3.Conclusion
Chapter7.WorkingwithTimesandDates
Section7.1.DeterminingtheCurrentTime
Section7.2.WorkingwithSpecificTimes(Post-epoch)
Section7.3.DeterminingtheDayoftheWeek
Section7.4.DeterminingtheDateofEaster
Section7.5.FindingtheNthWeekdayinaMonth
Section7.6.ConvertingBetweenSecondsandLargerUnits
Section7.7.ConvertingToandFromtheEpoch
Section7.8.WorkingwithLeapSeconds:Don't!
Section7.9.FindingtheDayoftheYear
Section7.10.ValidatingaDate/Time
Section7.11.FindingtheWeekoftheYear
Section7.12.DetectingLeapYears
Section7.13.ObtainingtheTimeZone
Section7.14.WorkingwithHoursandMinutesOnly
Section7.15.ComparingDate/TimeValues
Section7.16.AddingIntervalstoDate/TimeValues
Section7.17.ComputingtheDifferenceinTwoDate/TimeValues
Section7.18.WorkingwithSpecificDates(Pre-epoch)
Section7.19.InterconvertingBetweenTime,Date,andDateTime
Section7.20.RetrievingaDate/TimeValuefromaString
Section7.21.FormattingandPrintingDate/TimeValues
Section7.22.TimeZoneConversions
Section7.23.DeterminingtheNumberofDaysinaMonth
Section7.24.DividingaMonthintoWeeks
Section7.25.Conclusion
Chapter8.Arrays,Hashes,andOtherEnumerables

Section8.1.WorkingwithArrays
Section8.2.WorkingwithHashes
Section8.3.EnumerablesinGeneral
Section8.4.Conclusion
Chapter9.MoreAdvancedDataStructures
Section9.1.WorkingwithSets
Section9.2.WorkingwithStacksandQueues
Section9.3.WorkingwithTrees
Section9.4.WorkingwithGraphs
Section9.5.Conclusion
Chapter10.I/OandDataStorage
Section10.1.WorkingwithFilesandDirectories
Section10.2.PerformingHigher-LevelDataAccess
Section10.3.UsingKirbyBase
Section10.4.ConnectingtoExternalDatabases

Section10.5.Conclusion
Chapter11.OOPandDynamicFeaturesinRuby
Section11.1.EverydayOOPTasks
Section11.2.MoreAdvancedTechniques
Section11.3.WorkingwithDynamicFeatures
Section11.4.Conclusion
Chapter12.GraphicalInterfacesforRuby
Section12.1.Ruby/Tk
Section12.2.Ruby/GTK2
Section12.3.FXRuby(FOX)
Section12.4.QtRuby
Section12.5.OtherGUIToolkits
Section12.6.Conclusion
Chapter13.ThreadsinRuby
Section13.1.CreatingandManipulatingThreads
Section13.2.SynchronizingThreads
Section13.3.Conclusion
Chapter14.ScriptingandSystemAdministration
Section14.1.RunningExternalPrograms
Section14.2.Command-LineOptionsandArguments
Section14.3.TheShellLibrary
Section14.4.AccessingEnvironmentVariables
Section14.5.ScriptinginMicrosoftWindows
Section14.6.TheWindowsOne-ClickInstaller

Section14.7.LibrariesYouNeedtoKnowAbout
Section14.8.WorkingwithFiles,Directories,andTrees
Section14.9.MiscellaneousScriptingTasks
Section14.10.Conclusion
Chapter15.RubyandDataFormats
Section15.1.ParsingXMLwithREXML
Section15.2.WorkingwithRSSandAtom
Section15.3.ManipulatingImageDatawithRMagick
Section15.4.CreatingPDFDocumentswithPDF::Writer
Section15.5.Conclusion
Chapter16.TestingandDebugging
Section16.1.TestingwithTest::Unit
Section16.2.TheZenTestTools
Section16.3.UsingtheRubyDebugger
Section16.4.UsingirbAsaDebugger
Section16.5.MeasuringCodeCoverage
Section16.6.MeasuringPerformance
Section16.7.PrettyprintingObjects
Section16.8.Conclusion
Chapter17.PackagingandDistributingCode
Section17.1.UsingRDoc

Section17.2.InstallationandPackaging
Section17.3.RubyForgeandtheRAA
Section17.4.Conclusion
Chapter18.NetworkProgramming
Section18.1.NetworkServers
Section18.2.NetworkClients
Section18.3.Conclusion
Chapter19.RubyandWebApplications
Section19.1.CGIProgrammingwithRuby
Section19.2.UsingFastCGI
Section19.3.RubyonRails
Section19.4.WebDevelopmentwithNitro
Section19.5.AnIntroductiontoWee
Section19.6.WebDevelopmentwithIOWA
Section19.7.RubyandtheWebServer
Section19.8.Conclusion
Chapter20.DistributedRuby
Section20.1.AnOverview:Usingdrb

Section20.2.CaseStudy:AStockTickerSimulation
Section20.3.Rinda:ARubyTuplespace
Section20.4.ServiceDiscoverywithDistributedRuby
Section20.5.Conclusion
Chapter21.RubyDevelopmentTools
Section21.1.UsingRubyGems
Section21.2.UsingRake
Section21.3.Usingirb
Section21.4.TheriUtility
Section21.5.EditorSupport
Section21.6.IntegratedDevelopmentEnvironments
Section21.7.Conclusion
Chapter22.TheRubyCommunity
Section22.1.WebResources
Section22.2.NewsgroupandMailingLists
Section22.3.BlogsandOnlineMagazines
Section22.4.RubyChangeRequests
Section22.5.IRCChannels
Section22.6.RubyConferences
Section22.7.LocalRubyGroups
Section22.8.Conclusion
Index


Copyright
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TheRubyway:solutionsandtechniquesinRubyprogramming/HalFulto
-2nded.
p.cm.
Includesindex.
ISBN0-672-32884-4(pbk.:alk.paper)1.Objectorientedprogramming(Computerscience)2.Ruby

(Computerprogramlanguage)I.Title.

QA76.64.F852006
005.1'17dc22

Copyright©2007PearsonEducation,Inc.
Allrightsreserved.PrintedintheUnitedStatesofAmerica.This
publicationisprotectedbycopyright,andpermissionmustbe
obtainedfromthepublisherpriortoanyprohibited
reproduction,storageinaretrievalsystem,ortransmissionin
anyformorbyanymeans,electronic,mechanical,
photocopying,recording,orlikewise.Forinformationregarding
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TextprintedintheUnitedStatesonrecycledpaperatRR
DonnelleyinCrawfordsville,Indiana.
Firstprinting,October2006

Dedication
Tomyparents,withoutwhomIwouldnotbepossible



"Amongotherthings,thisbookexcelsatexplaining
metaprogramming,oneofthemostinterestingaspectsof
Ruby.ManyoftheearlyideasforRailswereinspiredby

thefirstedition,especiallywhatisnowchapter11.Itputs
youonarollercoasterridebetween'HowcouldIuse
this?'to'Thisissocool!'Onceyougetonthatroller
coaster,there'snoturningback."
DavidHeinemeierHansson,
CreatorofRubyonRails,
Partnerwith37signals
"Theappearanceofthesecondeditionofthisclassicbook
isanexcitingeventforRubyistsandforloversofsuperb
technicalwritingingeneral.HalFultonbringsalively
eruditionandanengaging,lucidstyletobearona
thoroughandmeticulouslyexactexpositionofRuby.You
palpablyfeelthepresenceofateacherwhoknowsa
tremendousamountandreallywantstohelpyouknowit
too."
DavidAlanBlack,
AuthorofRubyforRails
"Thisisanexcellentresourceforgaininginsightintohow
andwhyRubyworks.Assomeonewhohasworkedwith
Rubyforseveralyears,Istillfounditfullofnewtricksand
techniques.It'saccessiblebothasastraightreadandasa
referencethatonecandipintoandlearnsomethingnew."
ChetHendrickson,
Agilesoftwarepioneer


"IusethefirsteditionofHal'sbookfrequently,tolearn
aboutdetailsandstyleinRuby,becauseitcoversmany
topicsIcanfindnowhereelse.Theneweditioniseven
morecomprehensiveandwillbeevenmorevaluable."

RonJeffries,
Agileauthorandspeaker
"Ruby'sawonderfullanguagebutsometimesyoujustwant
togetsomethingdone.Hal'sbookgivesyouthesolution
andteachesagoodbitaboutwhythatsolutionisgood
Ruby."
MartinFowler
ChiefScientist,ThoughtWorks
AuthorofPatternsofEnterprise
ApplicationArchitecture




Foreword
ForewordtotheSecondEdition
InancientChina,people,especiallyphilosophers,thoughtthat
somethingwashiddenbehindtheworldandeveryexistence.It
canneverbetold,norexplained,nordescribedinconcrete
words.TheycalleditTaoinChineseandDoinJapanese.Ifyou
translateitintoEnglish,itisthewordforWay.ItistheDoin
Judo,Kendo,Karatedo,andAikido.Theyarenotonlymartial
arts,buttheyalsoincludeaphilosophyandawayoflife.
Likewise,Rubytheprogramminglanguagehasitsphilosophy
andwayofthinking.Itenlightenspeopletothinkdifferently.It
helpsprogrammershavemorefunintheirwork.Itisnot
becauseRubyisfromJapanbutbecauseprogrammingisan
importantpartofthehumanbeing(well,atleastsomehuman
beings),andRubyisdesignedtohelppeoplehaveabetterlife.
Asalways,"Tao"isdifficulttodescribe.Ifeelitbuthavenever

triedtoexplainitinwords.It'sjusttoodifficultforme,evenin
Japanese,mynativetongue.ButaguynamedHalFultontried,
andhisfirsttry(thefirsteditionofthisbook)wasprettygood.
ThissecondversionofhistrialtodescribetheTaoofRuby
becomesevenbetterwithhelpfrommanypeopleintheRuby
community.AsRubybecomesmorepopular(partlyduetoRuby
onRails),itbecomesmoreimportanttounderstandthesecret
ofprogrammers'productivity.Ihopethisbookhelpsyouto
becomeanefficientprogrammer.
HappyHacking.
Yukihiro"Matz"Matsumoto
August2006,Japan


ForewordtoFirstEdition
ShortlyafterIfirstmetwithcomputersintheearly80sI
becameinterestedinprogramminglanguages.SincethenI
havebeena"languagegeek."Ithinkthereasonforthis
interestisthatprogramminglanguagesarewaystoexpress
humanthought.Theyarefundamentallyhuman-oriented.
Despitethisfact,programminglanguageshavetendedtobe
machine-oriented.Manylanguagesweredesignedforthe
convenienceofthecomputer.
Butascomputersbecamemorepowerfulandlessexpensive,
thissituationgraduallychanged.Forexample,lookat
structuredprogramming.Machinesdonotcarewhether
programsarestructuredwell;theyjustexecutethembitbybit.
Structuredprogrammingisnotformachines,butforhumans.
Thisistrueofobject-orientedprogrammingaswell.
Thetimeforlanguagedesignfocusingonhumanshasbeen

coming.
In1993,Iwastalkingwithacolleagueaboutscripting
languages,abouttheirpowerandfuture.Ifeltscriptingtobe
thewayfutureprogrammingshouldbehuman-oriented.
ButIwasnotsatisfiedwithexistinglanguagessuchasPerland
Python.IwantedalanguagethatwasmorepowerfulthanPerl
andmoreobject-orientedthanPython.Icouldn'tfindtheideal
language,soIdecidedtomakemyown.
Rubyisnotthesimplestlanguage,butthehumansoulisnot
simpleinitsnaturalstate.Itlovessimplicityandcomplexityat
thesametime.Itcan'thandletoomanycomplexthings,nor
toomanysimplethings.It'samatterofbalance.


Sotodesignahuman-orientedlanguage,Ruby,Ifollowedthe
PrincipleofLeastSurprise.Iconsiderthateverythingthat
surprisesmelessisgood.AsaresultIfeelanaturalfeeling,
evenakindofjoy,whenprogramminginRuby.Andsincethe
firstreleaseofRubyin1995,manyprogrammersworldwide
haveagreedwithmeaboutthejoyofRubyprogramming.
AsalwaysI'dliketoexpressmygreatestappreciationtothe
peopleintheRubycommunity.TheyaretheheartofRuby's
success.
Iamalsothankfultotheauthorofthisbook,HalE.Fulton,for
declaringtheRubyWaytohelppeople.
ThisbookexplainsthephilosophybehindRuby,distilledfrom
mybrainandtheRubycommunity.Iwonderhowitcanbe
possibleforHaltoreadmymindtoknowandrevealthissecret
oftheRubyWay.Ihavenevermethimfacetoface;Ihopeto
meethimsoon.

IhopethisbookandRubybothservetomakeyour
programmingfunandhappy.
Yukihiro"Matz"Matsumoto
September2001,Japan




Acknowledgments
AcknowledgmentsfortheSecondEdition
Commonsensesaysthatasecondeditionwillonlyrequirehalf
asmuchworkasthefirsteditionrequired.Commonsenseis
wrong.
Eventhoughalargepartofthisbookcamedirectlyfromthe
firstedition,eventhatparthadtobetweakedandtuned.Every
singlesentenceinthisbookhadtopassthrough(atthevery
least)afilterthatasked:Iswhatwastruein2001stilltruein
2006?Andthat,ofcourse,wasonlythebeginning.
Inshort,Iputinmanyhundredsofhoursofworkonthis
secondeditionnearlyasmuchtimeasonthefirst.AndyetIam
"onlytheauthor."
Abookispossibleonlythroughtheteamworkofmanypeople.
Onthepublisher'sside,IowethankstoDebraWilliamsCauley,
SonglinQiu,andMandieFrankfortheirhardworkandinfinite
patience.ThanksgotoGeneilBreezeforhertireless
copyeditingandpickingbitsoflintfrommyEnglish.Thereare
alsoothersIcan'tnamebecausetheirworkwascompletely
behindthescenes,andInevertalkedwiththem.
TechnicaleditingwasdoneprimarilybyShashankDateand
FrancisHwang.Theydidagreatjob,andIappreciateit.Errors

thatslippedthrougharemyresponsibility,ofcourse.
Thanksgotothepeoplewhosuppliedexplanations,wrote
samplecode,andanswerednumerousquestionsforme.These
includeMatzhimself(YukihiroMatsumoto),DaveThomas,
ChristianNeukirchen,ChadFowler,CurtHibbs,DanielBerger,
ArminRoehrl,StefanSchmiedl,JimWeirich,RyanDavis,Jenny


W.,JimFreeze,LyleJohnson,MartinDeMello,MattLawrence,
theinfamouswhytheluckystiff,RonJeffries,TimHunter,Chet
Hendrickson,NathanielTalbott,andBilKleb.
Specialthanksgoestotheheaviercontributors.Andrew
Johnsongreatlyenhancedmyregularexpressionknowledge.
PaulBattleymadegreatcontributionstotheinternationalization
chapter.MasaoMutohaddedtothatsamechapterandalso
contributedmaterialonGTK.AustinZieglertaughtmethe
secretsofwritingPDFfiles.CalebTennisaddedtotheQt
material.EricHodeladdedtotheRindaandRingmaterial,and
JamesBrittcontributedheavilytothewebdevelopment
chapter.
ThanksandappreciationagainmustgotoMatz,notonlyforhis
assistancebutforcreatingRubyinthefirstplace.Domoarigato
gozaimasu!
AgainIhavetothankmyparents.Theyhaveencouragedme
withoutceasingandarelookingforwardtoseeingthisbook.I
willmakeprogrammersofthembothyet.
Andonceagain,IhavetothankalloftheRubycommunityfor
theirtirelessenergy,productivity,andcommunityspirit.I
particularlythankthereadersofthisbook(inbotheditions).I
hopeyoufinditinformative,useful,andperhapseven

entertaining.

AcknowledgmentsfortheFirstEdition
Writingabookistrulyateameffort;thisisafactIcouldnot
fullyappreciateuntilIwroteonemyself.Irecommendthe
experience,althoughitisahumblingone.Itisasimpletruth
thatwithouttheassistanceofmanyotherpeople,thisbook
wouldnothaveexisted.
ThanksandappreciationmustfirstgotoMatz(Yukihiro


Matsumoto),whocreatedtheRubylanguageinthefirstplace.
Domoarigatogozaimasu!
ThanksgoestoConradSchneikerforconceivingtheoverallidea
forthebookandhelpingtocreateitsoverallstructure.Healso
didmetheserviceofintroducingmetotheRubylanguagein
1999.
Severalindividualshavecontributedmaterialtothebodyofthe
book.TheforemostofthesewasGuyHurst,whowrote
substantialpartsoftheearlierchaptersaswellastwoofthe
appendices.Hisassistancewasabsolutelyinvaluable.
Thanksalsogoestotheothercontributors,whomI'llnamein
noparticularorder.KevinSmithdidagreatjobontheGTK
sectionofChapter6,savingmefromapotentiallysteep
learningcurveonatightschedule.PatrickLogan,inthesame
chapter,shedlightonthemysteriesoftheFOXGUI.Chad
Fowler,inChapter9,plumbedthedepthsofXMLandalso
contributedtotheCGIsection.
Thankstothosewhoassistedinproofreadingorreviewingorin
othermiscellaneousways:DonMuchow,MikeStok,Miho

Ogishima,andothersalreadymentioned.ThankstoDavid
Eppstein,themathematicsprofessor,foransweringquestions
aboutgraphtheory.
OneofthegreatthingsaboutRubyisthesupportofthe
community.Thereweremanyonthemailinglistandthe
newsgroupwhoansweredquestionsandgavemeideasand
assistance.Againinnoparticularorder,theseareDave
Thomas,AndyHunt,Hee-SobPark,MikeWilson,AviBryant,
YasushiShoji("Yashi"),ShugoMaeda,JimWeirich,"arton,"and
MasakiSuketa.I'msorrytosayIhaveprobablyoverlooked
someone.
Tostatetheobvious,abookwouldneverbepublishedwithout
apublisher.Manypeoplebehindthescenesworkedhardto


producethisbook;primarilyIhavetothankWilliamBrown,
whoworkedcloselywithmeandwasaconstantsourceof
encouragement;andScottMeyer,whodelveddeeplyintothe
detailsofputtingthematerialtogether.OthersIcannoteven
namebecauseIhaveneverheardofthem.Youknowwhoyou
are.
Ihavetothankmyparents,whowatchedthisprojectfroma
distance,encouragedmealongtheway,andevenbotheredto
learnalittlebitofcomputerscienceformysake.
Awriterfriendofmineoncetoldme,"Ifyouwriteabookand
nobodyreadsit,youhaven'treallywrittenabook."So,finally,I
wanttothankthereader.Thisbookisforyou.Ihopeitisof
somevalue.

AbouttheAuthor
HalFultonhastwodegreesincomputersciencefromthe
UniversityofMississippi.Hetaughtcomputerscienceforfour
yearsatthecommunitycollegelevelbeforemovingtoAustin,
Texas,foraseriesofcontracts(mainlyatIBMAustin).Hehas
workedformorethan15yearswithvariousformsofUNIX,
includingAIX,Solaris,andLinux.HewasfirstexposedtoRuby
in1999,andin2001hebeganworkonthefirsteditionofthis
book,whichwasthesecondRubybookintheEnglishlanguage.
HehasattendedsixRubyconferencesandhasgiven
presentationsatfourofthose,includingthefirstEuropeanRuby
ConferenceinKarlsruhe,Germany.Hecurrentlyworksat
BroadwingCommunicationsinAustin,Texas,workingonalarge
datawarehouseandrelatedtelecomapplications.Heworks
dailywithC++,Oracle,andofcourse,Ruby.
HalisstillactivedailyontheRubymailinglistandIRCchannel,
andhasseveralRubyprojectsinprogress.Heisamemberof
theACMandtheIEEEComputerSociety.Inhispersonallife,he
enjoysmusic,reading,writing,art,andphotography.Heisa
memberoftheMarsSocietyandisaspaceenthusiastwho
wouldlovetogointospacebeforehedies.HelivesinAustin,
Texas.


Introduction
ThewaythatcanbenamedisnotthetrueWay.
LaoTse,TaoTeChing
ThetitleofthisbookisTheRubyWay.Thisisatitlethatbegs

foradisclaimer.
Ithasbeenmyaimtoalignthisbookwiththephilosophyof
RubyaswellasIcould.Thathasalsobeentheaimoftheother
contributors.Creditforsuccessmustbesharedwiththese
others,buttheblameforanymistakesmustrestsolelywith
me.
Ofcourse,Ican'tpresumetotellyouwithexactnesswhatthe
spiritofRubyisallabout.ThatisprimarilyforMatztosay,and
Ithinkevenhewouldhavedifficultycommunicatingallofitin
words.
Inshort,TheRubyWayisonlyabook;buttheRubyWayisthe
provinceofthelanguagecreatorandthecommunityasa
whole.Thisissomethingdifficulttocaptureinabook.
StillIhavetriedinthisintroductiontopindownalittleofthe
ineffablespiritofRuby.ThewisestudentofRubywillnottakeit
astotallyauthoritative.
Beawarethatthisisasecondedition.Manythingshavestayed
thesame,butmanythingshavechanged.Mostofthis
introductionhasbeenpreserved,butyouwillwanttovisitthe
upcomingsection,"AbouttheSecondEdition,"whereI
summarizethechangesandthenewmaterial.

AbouttheSecondEdition


Everythingchanges,andRubyisnoexception.AsIwritethis
introductioninAugust2006,thefirsteditionofthisbookis
nearlyfiveyearsold.Itiscertainlytimeforanupdate.
Therearemanychangesandmuchnewmaterialinthisedition.
TheoldChapter4("SimpleDataTasks")isnowsplitintosix

chapters,twoofwhich("RangesandSymbols"and
"InternationalizationinRuby")aretotallynew;theotherfour
alsohavenewexamplesandcommentaryaddedtothem.The
coverageofregualrexpressionsisparticularlyexpanded,
coveringnotonly"classic"regexesbutthenewerOniguruma
regexengine.
Chapters8and9wereoriginallyonechapter.Thiswassplitas
materialwasaddedandthechaptergrewtoobig.
Inthesameway,thecurrentchapters18,19,and20grewout
oftheoldchapter9asmaterialwasadded.Theappendices
weredeletedtomakeroomformorematerial.
Othernewchaptersare:
Chapter15,"RubyandDataFormats."ThiscoversXML,
RSS,imagefiles,writingPDFfiles,andmore.
Chapter16,"TestingandDebugging."Thisdealswithunit
testing,profiling,debugging,codecoverage,andsimilar
topics.
Chapter17,"PackagingandDistributingCode."Thischapter
coverstheuseofsetup.rb,thecreationofRubyGems,and
more.
Chapter21,"RubyDevelopmentTools."Thisoffersalookat
RubyeditorsupportandIDEs,theriutility,andRubyGems
fromauser'sperspective.


Chapter22,"TheRubyCommunity."Thischapter
summarizesallthemajorwebsites,mailinglists,
newsgroups,conferences,IRCchannels,andmore.
Inalargersense,everysinglechapterinthisbookis"new."I
haverevisedandupdatedeveryoneofthem,makinghundreds

ofminorchangesanddozensofmajorchanges.Ideleteditems
thatwereobsoleteoroflesserimportance;Ichangedmaterial
tofitchangesinRubyitself;andIaddednewexamplesand
commentarytoeverychapter.
Youmaywonderwhathasbeenaddedtotheoldchapters.
SomeofthehighlightsaretheOnigurumacoverage,whichI
alreadymentioned;coverageofmathlibrariesandclassessuch
asBigDecimal,mathn,andmatrix;andnewclassessuchasSetand
DateTime.
InChapter10,"I/OandDataStorage,"Iaddedmaterialon
readpartial,onnonblockingI/O,andontheStringIOclass.Ialso
addedmaterialonCSV,YAML,andKirbyBase.Inthedatabase
portionofthatsamechapterIaddedOracle,SQLite,DBI,anda
discussionofObject-RelationalMappers(ORMs).
Chapter11,"OOPandDynamicFeaturesinRuby,"nowincludes
morerecentadditionstoRubysuchasinitialize_copy,const_get,
const_missing,anddefine_method.Ialsoaddedcoverageof
delegationandforwardingtechniques.
AllofChapter12,"GraphicalInterfacesforRuby,"hadtobe
revised(especiallytheGTKandFoxsections).TheQtRuby
sectionistotallynew.
Chapter14,"ScriptingandSystemAdministration,"now
discussestheWindowsone-clickinstallerandafewsimilar
packages.Italsohasseveralimprovementsintheexample
code.


Chapter18,"NetworkProgramming,"nowhasasectionon
emailattachmentsandanothernewsectiononinteractingwith
anIMAPserver.ItalsohascoverageoftheOpenURIlibrary.

Chapter19,"RubyandWebApplications,"nowcoversRubyon
Rails,Nitro,Wee,IOWA,andotherwebtools.Italsohas
coverageofWEBrickandsomecoverageofMongrel.
Chapter20,"DistributedRuby,"hasnewmaterialexplaining
Rinda,theRubytuplespaceimplementation.ItalsocoversRing,
whichiscloselyrelated.
Werealltheseadditionsnecessary?Iassureyoutheywere.
Fortherecord,TheRubyWaywasthesecondRubybookinthe
Englishlanguage(followingthefamous"Pickaxe,"or
ProgrammingRuby,byDaveThomasandAndyHunt).Itwas
carefullydesignedtobecomplementarytothatbookrather
thanoverlappingit;thisisalargepartofthereasonforits
popularity.
WhenIbeganwritingthefirstedition,therewasno
internationalRubyconference.TherewasnoRubyForge,no
ruby-doc.org,andnorubygarden.orgwiki.Inessencetherewas
littleontheWebbesidesthemainRubysite.TheRuby
ApplicationArchivehadafewhundredentriesinit.
Atthattime,fewpublications(onlineoroff)seemedtoknowof
Ruby'sexistence.AnytimeanarticlewaspublishedaboutRuby,
itwascauseforustotakenotice;itwasannouncedonthe
mailinglistanddiscussedthere.
ManycommonRubytoolsandlibrariesalsodidnotexist.There
wasnoRDoc;therewasnoREXMLtoparseXML;themath
librarywasconsiderablylessrichthanitisnow.Database
supportwasspotty,andtherewasnoODBC.Tkwasbyfarthe
mostusedGUItoolkit.Themostcommonwayofdoingweb
developmentwasthelow-levelCGIlibrary.