text editor

Introduction

Texteditorisakindofcomputersoftware.Mainlyusedtowriteandviewtextfiles.Therearesomespecialtexteditorsthatsupportaddingtheirownformatstoenrichthepresentationformofthedocument.Theoperatingsystemorintegrateddevelopmentenvironmentusuallyhasaneditorthatcanviewandeditplaintext,andthetexteditorthatcanincreasetheformatisusuallyusedbyindividualusersorcompaniesintheproductionoffilesthatrequireaformat.Becauseprogramsandprogramconfigurationfilesareusuallystoredinplaintext,programmersalsoneedtouseaplaintexteditortoeditprogramsandconfigurationfiles.

Texteditorsundercommonsystems

CommononesareNotepadunderWindows,texteditorunderMacOSX,vi,LinuxunderLinuxemacs,gedit,editunderDOS,etc.

Useundereachsystem

1.Windowsstart/run,entertheeditcommandtoenterthetexteditortoeditthetext;youcanalsoentereditundercmdtoenterthetexteditor.Thetexteditorissimilartotheclanguageinterface.Itisaverypracticaltexteditingsoftware.

2.ForMacOSX,findthetexteditor.app(sourcename:TextEdit.app)intheapplicationfolderunderthediskorLaunchpad(MacOSXLion10.7orabove),andopenit.Createanewdocumentandimplementediting.Texteditingsupportsrichtextformat(.rtf),richtextformatwithattachments(.rtfd),(.html),Webarchive(.webarchive),OpenDocumenttext(.odt),Word2007format(.docx),Word2003format(.xml),Word1997format(.doc)andplaintext(.txt)fileproduction,andexportoftheabovefilesinportabledocumentformat(.pdf).ThetexteditorcanopenalmostalldocumentformatscompatiblewithMacOSX.

3.EntertheterminalunderLinux,enterthenameofthetexteditor,andpressEntertorun.

Type

Sometexteditorsareshortandpowerful,andsometexteditorsproviderichandcomplexfunctions.Forexample,bothUnixandUnix-likeoperatingsystemsprovidethevieditor(oritsvariants),butsomeoperatingsystemsalsoprovidetheEmacseditor.Windowssystemprovidesaverysimplenotepad,butmanypeople,especiallythoseprogrammers,preferothereditorswithricherfunctionsunderWindows.IntheclassicMacOSofAppleMacintosh,SimpleTextwasincluded.Later,TextEditreplacedit.Someeditorssupporttwomodesofoperation,bothasatexteditorandasawordprocessor.WordStarisanexample.

Thetexteditorsusedbyprofessionalcomputerusersoftendonotlimitthesizeofopenfiles.Sucheditorsstillstartquicklywheneditinglargefiles,andtheycanalsoeditfilesthatexceedthememorysize.Asimpletexteditorusuallyreadsthefiledirectlyintomemory.Inthisway,thespeedisslowerwhenprocessinglargerfiles,anditsimplycannotbeprocessedforlargerfiles.

Professionalcomputersneedtheabilitytohandlelargefiles.Forexample,systemadministratorsneedtoreadverylonglogfiles;programmersneedtomodifyverylargesourcecodefiles,orcheckunusuallylargefiles,suchasfilesusedtostoreentiredictionaries.

Sometexteditorscontainspecialcomputerlanguages,whichcanbecustomizedusingthislanguage(programmableeditor).Forexample,youcancustomizeEmacswithLispprograms.Usingthismethod,theusercanusuallysimulatetheshortcutkeycombinationofacertaineditorandsomeotherfeaturesasanothereditor,sothattheuserdoesnotneedtolearnthecommandcombinationofthiseditor.

TherearealsosomeprogrammableeditorsthatuseREXXastheirscriptinglanguage.TheseeditorssupportdirectinputofcommandsorREXXstatementsatthebottomofthescreen.Peopleusuallythinkoftheseeditorsasorthodoxeditors.Inthistypeofeditor,themostrepresentativeisthefollow-upproductofXedit,andXeditisIBM'seditorinVM/CMS.Somevifollow-upproducts,suchasVim,alsosupportfoldingandmacros,andtherearecommandlinesatthebottom.Peoplethinkofthemasanotherkindoforthodoxeditor.

Manytexteditorsusedtodevelopsoftwaresupportsyntaxhighlightingandauto-completionofsourcecode,whichmakestheprogrameasiertoreadandwrite.Theprogrameditorusuallyallowsyoutoselectasubroutineorvariable,thenjumptoitsdefinitionpart,andthenjumpbacktotheoriginalposition.Additionaltoolslikectagsarespecificallyusedtolocatethedefinitionpart.

Withthedevelopmentofcomputernetworks,texteditorsthatcanbeeditedbymultiplepeoplehavebeenborn,suchasNetpadundertheWindowsoperatingsystem,whichallowsmultiplepeopletoeditorreadthesametextfileatthesametime.

Therearealsosomegoodopensourcetexteditors,suchasNotePad++,PSPad,Komodo,Coda,etc.

Typicalfunctions

FindandReplace

Findawordoracharacterstringinatextfile,andreplaceonecharacterstringwithanothercharacterstring.Variousmethodscanbeadopted:globalsearchandreplacement,conditionalsearchandreplacement,andunconditionalsearchandreplacement.

Cut,Copy,Paste

Mosttexteditorssupportcopyingormovingwithinorbetweenfiles.

Texttypesetting

Texteditorsusuallysupportbasictypesettingfunctions,suchasscrolling,automaticindentation,linenumbertypesetting,commenttypesettingandsoon.

Undoandredo

Likewordprocessors,texteditorsalsosupportundoandredo.Usually,especiallyoldtexteditors,onlysupportone-leveleditinghistory,andcanonlyundoorrestoretothelastchange.Modernandcomplextexteditorssupportmulti-leveleditinghistory,sothatitcanbeundoneorrestoredtoanyhistoricalstate.Thenumberofchangesthatcanberecordedvarieswithdifferenteditors,andisusuallyconfigurable.

Import

Readormergethecontentofanothertextfiletothefilecurrentlybeingedited.Sometexteditorssupportinsertingtheoutputofoperatingsystemcommands.

Filtering

Someadvancedtexteditorsallowyoutosendthefileyouareeditingtoanothertoolandreadbackthefilteredresultstothisfile.Forexample,thismethodcansortsomerows,orperformmathematicalcalculations.

History

Aboxofpunchedcardscontainingseveralprograms.

Beforetheadventoftexteditors,peopleusedpunchingmachinestopunchcomputertextonpunchcards.Thetextisstoredinaboxcontainingsuchathincard,whichcanbereadwithacardreader.

Thefirsttexteditorisalineeditor,whichrunsonatypingterminal.Thiseditordoesnothavethefunctionofdisplayinginwindowsandscreens.Itcontainssomeveryshortcommands(inordertoreducetheamountoftyping).Oneofthecommandscanprintoutthespecifiedpartofthefilethroughatypewriter.Theeditcursorisanimaginaryinsertionpoint,whichcanbemovedtothelinewherethespecificcontentstringislocatedthroughspecialcommands.Subsequently,thecontentstringwasexpandedintoregularexpressions.Ifyouwanttoseethechangesinthefile,youneedtoprintitout.Comparedwiththepuncher,peoplethinkthatthisline-basedtexteditorisarevolutionaryadvancement.Withoutit,usersneedtomarkthosecommandsforprocessingtextintospecialcardsandusethesecardswheneditingfiles.

Whencomputerterminalswithdisplayscreensappeared,texteditorsbasedondisplayscreensbecamepopular.Oneoftheearliestfull-screeneditorswascalledO26,whichwasmadein1967fortheoperationconsoleofCDC6000seriesmachines.Anotherearlyfull-screeneditorwasvi.viwasborninthe1970s,anditisstillthestandardeditorforUnixandLinux.Thefull-screeneditorhasplayedaroleinpromotingthesalesofvideoterminals.

Comparison

Thistablecomparesthegeneralinformationofeacheditor: