perl linux command man page

Perl officially stands for Practical Extraction and Report Language, except when it doesn't. ... Perl was originally a language optimized for ... Togglenavigation LinuxCommands Manpages Allmanualsections Section1:UserCommands Section2:SystemCalls Section3:CLibraryFunctions Section4:DevicesandSpecialFiles Section5:FileFormatsandConventions Section6:Gameset.al. Section7:Miscellanea Section8:SystemAdministrationtoolsandDaemons Blog PERL Section:PerlProgrammersReferenceGuide(1)Updated:2016-07-22Index ReturntoMainContents   NAME perl-ThePerl5languageinterpreter   SYNOPSIS perl   [ -sTtuUWX ]         [ -hv ] [ -V[:configvar] ]         [ -cw ] [ -d[t][:debugger] ] [ -D[number/list] ]         [ -pna ] [ -Fpattern ] [ -l[octal] ] [ -0[octal/hexadecimal] ]         [ -Idir ] [ -m[-]module ] [ -M[-]'module...' ] [ -f ]         [ -C [number/list] ]         [ -S ]         [ -x[dir] ]         [ -i[extension] ]         [ [-e|-E] 'command' ] [ -- ] [ programfile ] [ argument ]... Formoreinformationontheseoptions,youcanrun"perldocperlrun".   GETTINGHELP Theperldocprogramgivesyouaccesstoallthedocumentationthatcomes withPerl.Youcangetmoredocumentation,tutorialsandcommunitysupport onlineat. Ifyou'renewtoPerl,youshouldstartbyrunning"perldocperlintro", whichisageneralintroforbeginnersandprovidessomebackgroundtohelp younavigatetherestofPerl'sextensivedocumentation.Run"perldoc perldoc"tolearnmorethingsyoucandowithperldoc. Foreaseofaccess,thePerlmanualhasbeensplitupintoseveralsections.   Overview perlPerloverview(thissection) perlintroPerlintroductionforbeginners perlrunPerlexecutionandoptions perltocPerldocumentationtableofcontents   Tutorials perlreftutPerlreferencesshortintroduction perldscPerldatastructuresintro perllolPerldatastructures:arraysofarrays perlrequickPerlregularexpressionsquickstart perlretutPerlregularexpressionstutorial perlootutPerlOOtutorialforbeginners perlperfPerlPerformanceandOptimizationTechniques perlstylePerlstyleguide perlcheatPerlcheatsheet perltrapPerltrapsfortheunwary perldebtutPerldebuggingtutorial perlfaqPerlfrequentlyaskedquestions perlfaq1GeneralQuestionsAboutPerl perlfaq2ObtainingandLearningaboutPerl perlfaq3ProgrammingTools perlfaq4DataManipulation perlfaq5FilesandFormats perlfaq6Regexes perlfaq7PerlLanguageIssues perlfaq8SystemInteraction perlfaq9Networking   ReferenceManual perlsynPerlsyntax perldataPerldatastructures perlopPerloperatorsandprecedence perlsubPerlsubroutines perlfuncPerlbuilt-infunctions perlopentutPerlopen()tutorial perlpacktutPerlpack()andunpack()tutorial perlpodPerlplainolddocumentation perlpodspecPerlplainolddocumentationformatspecification perlpodstylePerlPODstyleguide perldiagPerldiagnosticmessages perllexwarnPerlwarningsandtheircontrol perldebugPerldebugging perlvarPerlpredefinedvariables perlrePerlregularexpressions,therestofthestory perlrebackslashPerlregularexpressionbackslashsequences perlrecharclassPerlregularexpressioncharacterclasses perlrerefPerlregularexpressionsquickreference perlrefPerlreferences,therestofthestory perlformPerlformats perlobjPerlobjects perltiePerlobjectshiddenbehindsimplevariables perldbmfilterPerlDBMfilters perlipcPerlinterprocesscommunication perlforkPerlfork()information perlnumberPerlnumbersemantics perlthrtutPerlthreadstutorial perlportPerlportabilityguide perllocalePerllocalesupport perluniintroPerlUnicodeintroduction perlunicodePerlUnicodesupport perlunicookPerlUnicodecookbook perlunifaqPerlUnicodeFAQ perlunipropsIndexofUnicodepropertiesinPerl perlunitutPerlUnicodetutorial perlebcdicConsiderationsforrunningPerlonEBCDICplatforms perlsecPerlsecurity perlmodPerlmodules:howtheywork perlmodlibPerlmodules:howtowriteanduse perlmodstylePerlmodules:howtowritemoduleswithstyle perlmodinstallPerlmodules:howtoinstallfromCPAN perlnewmodPerlmodules:preparinganewmodulefordistribution perlpragmaPerlmodules:writingauserpragma perlutilutilitiespackagedwiththePerldistribution perlfilterPerlsourcefilters perldtracePerl'ssupportforDTrace perlglossaryPerlGlossary   InternalsandCLanguageInterface perlembedPerlwaystoembedperlinyourCorC++application perldebgutsPerldebugginggutsandtips perlxstutPerlXStutorial perlxsPerlXSapplicationprogramminginterface perlxstypemapPerlXSC/Perltypeconversiontools perlclibInternalreplacementsforstandardClibraryfunctions perlgutsPerlinternalfunctionsforthosedoingextensions perlcallPerlcallingconventionsfromC perlmroapiPerlmethodresolutionplugininterface perlreapiPerlregularexpressionplugininterface perlregutsPerlregularexpressionengineinternals perlapiPerlAPIlisting(autogenerated) perlinternPerlinternalfunctions(autogenerated) perliolCAPIforPerl'simplementationofIOinLayers perlapioPerlinternalIOabstractioninterface perlhackPerlhackersguide perlsourceGuidetothePerlsourcetree perlinterpOverviewofthePerlinterpretersourceandhowitworks perlhacktutWalkthroughthecreationofasimpleCcodepatch perlhacktipsTipsforPerlcoreCcodehacking perlpolicyPerldevelopmentpolicies perlgitUsinggitwiththePerlrepository   Miscellaneous perlbookPerlbookinformation perlcommunityPerlcommunityinformation perldocLookupPerldocumentationinPodformat perlhistPerlhistoryrecords perldeltaPerlchangessincepreviousversion perl5201deltaPerlchangesinversion5.20.1 perl5200deltaPerlchangesinversion5.20.0 perl5184deltaPerlchangesinversion5.18.4 perl5182deltaPerlchangesinversion5.18.2 perl5181deltaPerlchangesinversion5.18.1 perl5180deltaPerlchangesinversion5.18.0 perl5163deltaPerlchangesinversion5.16.3 perl5162deltaPerlchangesinversion5.16.2 perl5161deltaPerlchangesinversion5.16.1 perl5160deltaPerlchangesinversion5.16.0 perl5144deltaPerlchangesinversion5.14.4 perl5143deltaPerlchangesinversion5.14.3 perl5142deltaPerlchangesinversion5.14.2 perl5141deltaPerlchangesinversion5.14.1 perl5140deltaPerlchangesinversion5.14.0 perl5125deltaPerlchangesinversion5.12.5 perl5124deltaPerlchangesinversion5.12.4 perl5123deltaPerlchangesinversion5.12.3 perl5122deltaPerlchangesinversion5.12.2 perl5121deltaPerlchangesinversion5.12.1 perl5120deltaPerlchangesinversion5.12.0 perl5101deltaPerlchangesinversion5.10.1 perl5100deltaPerlchangesinversion5.10.0 perl589deltaPerlchangesinversion5.8.9 perl588deltaPerlchangesinversion5.8.8 perl587deltaPerlchangesinversion5.8.7 perl586deltaPerlchangesinversion5.8.6 perl585deltaPerlchangesinversion5.8.5 perl584deltaPerlchangesinversion5.8.4 perl583deltaPerlchangesinversion5.8.3 perl582deltaPerlchangesinversion5.8.2 perl581deltaPerlchangesinversion5.8.1 perl58deltaPerlchangesinversion5.8.0 perl561deltaPerlchangesinversion5.6.1 perl56deltaPerlchangesinversion5.6 perl5005deltaPerlchangesinversion5.005 perl5004deltaPerlchangesinversion5.004 perlexperimentAlistingofexperimentalfeaturesinPerl perlartisticPerlArtisticLicense perlgplGNUGeneralPublicLicense   Language-Specific perlcnPerlforSimplifiedChinese(inEUC-CN) perljpPerlforJapanese(inEUC-JP) perlkoPerlforKorean(inEUC-KR) perltwPerlforTraditionalChinese(inBig5)   Platform-Specific perlaixPerlnotesforAIX perlamigaPerlnotesforAmigaOS perlandroidPerlnotesforAndroid perlbs2000PerlnotesforPOSIX-BCBS2000 perlcePerlnotesforWinCE perlcygwinPerlnotesforCygwin perldosPerlnotesforDOS perlfreebsdPerlnotesforFreeBSD perlhaikuPerlnotesforHaiku perlhpuxPerlnotesforHP-UX perlhurdPerlnotesforHurd perlirixPerlnotesforIrix perllinuxPerlnotesforLinux perlmacosPerlnotesforMacOS(Classic) perlmacosxPerlnotesforMacOSX perlnetwarePerlnotesforNetWare perlopenbsdPerlnotesforOpenBSD perlos2PerlnotesforOS/2 perlos390PerlnotesforOS/390 perlos400PerlnotesforOS/400 perlplan9PerlnotesforPlan9 perlqnxPerlnotesforQNX perlriscosPerlnotesforRISCOS perlsolarisPerlnotesforSolaris perlsymbianPerlnotesforSymbian perlsynologyPerlnotesforSynology perltru64PerlnotesforTru64 perlvmsPerlnotesforVMS perlvosPerlnotesforStratusVOS perlwin32PerlnotesforWindows   StubsforDeletedDocuments perlboot perlbot perlrepository perltodo perltooc perltoot OnDebiansystems,youneedtoinstalltheperl-docpackagewhich containsthemajorityofthestandardPerldocumentationandthe perldocprogram. ExtensiveadditionaldocumentationforPerlmodulesisavailable,both thosedistributedwithPerlandthird-partymoduleswhicharepackaged orlocallyinstalled. YoushouldbeabletoviewPerl'sdocumentationwithyourman(1) programorperldoc(1). Somedocumentationisnotavailableasmanpages,soifa cross-referenceisnotfoundbyman,tryitwithperldoc.Perldoccan alsotakeyoudirectlytodocumentationforfunctions(withthe-f switch).See"perldoc--help"(or"perldocperldoc"or"manperldoc") forotherhelpfuloptionsperldochastooffer. Ingeneral,ifsomethingstrangehasgonewrongwithyourprogramandyou're notsurewhereyoushouldlookforhelp,trymakingyourcodecomplywith usestrictandusewarnings.Thesewilloftenpointoutexactly wherethetroubleis.   DESCRIPTION PerlofficiallystandsforPracticalExtractionandReportLanguage, exceptwhenitdoesn't. Perlwasoriginallyalanguageoptimizedforscanningarbitrary textfiles,extractinginformationfromthosetextfiles,andprinting reportsbasedonthatinformation.Itquicklybecameagoodlanguage formanysystemmanagementtasks.Overtheyears,Perlhasgrowninto ageneral-purposeprogramminglanguage.It'swidelyusedforeverything fromquick``one-liners''tofull-scaleapplicationdevelopment. Thelanguageisintendedtobepractical(easytouse,efficient, complete)ratherthanbeautiful(tiny,elegant,minimal).Itcombines (intheauthor'sopinion,anyway)someofthebestfeaturesofsed, awk,andsh,makingitfamiliarandeasytouseforUnixusersto whipupquicksolutionstoannoyingproblems.Itsgeneral-purpose programmingfacilitiessupportprocedural,functional,and object-orientedprogrammingparadigms,makingPerlacomfortable languageforthelonghaulonmajorprojects,whateveryourbent. Perl'srootsintextprocessinghaven'tbeenforgottenovertheyears. Itstillboastssomeofthemostpowerfulregularexpressionstobe foundanywhere,anditssupportforUnicodetextisworld-class.It handlesallkindsofstructuredtext,too,throughanextensive collectionofextensions.Thoselibraries,collectedintheCPAN, provideready-madesolutionstoanastoundingarrayofproblems.When theyhaven'tsetthestandardthemselves,theystealfromthebest ---justlikePerlitself.   AVAILABILITY Perlisavailableformostoperatingsystems,includingvirtually allUnix-likeplatforms.See``SupportedPlatforms''inperlport foralisting.   ENVIRONMENT Seeperlrun.   AUTHOR LarryWall,withthehelpofoodlesofotherfolks. IfyourPerlsuccessstoriesandtestimonialsmaybeofhelptoothers whowishtoadvocatetheuseofPerlintheirapplications, orifyouwishtosimplyexpressyourgratitudetoLarryandthe Perldevelopers,[email protected].   FILES "@INC"locationsofperllibraries   SEEALSO http://www.perl.org/thePerlhomepage http://www.perl.com/Perlarticles(O'Reilly) http://www.cpan.org/theComprehensivePerlArchive http://www.pm.org/thePerlMongers   DIAGNOSTICS Usingthe"usestrict"pragmaensuresthatallvariablesareproperly declaredandpreventsothermisusesoflegacyPerlfeatures. The"usewarnings"pragmaproducessomelovelydiagnostics.Onecan alsousethe-wflag,butitsuseisnormallydiscouraged,because itgetsappliedtoallexecutedPerlcode,includingthatnotunder yourcontrol. SeeperldiagforexplanationsofallPerl'sdiagnostics.The"use diagnostics"pragmaautomaticallyturnsPerl'snormallytersewarnings anderrorsintotheselongerforms. Compilationerrorswilltellyouthelinenumberoftheerror,withan indicationofthenexttokenortokentypethatwastobeexamined. (InascriptpassedtoPerlvia-eswitches,each -eiscountedasoneline.) Setuidscriptshaveadditionalconstraintsthatcanproduceerror messagessuchas``Insecuredependency''.Seeperlsec. Didwementionthatyoushoulddefinitelyconsiderusingtheusewarnings pragma?   BUGS Thebehaviorimpliedbytheusewarningspragmaisnotmandatory. Perlisatthemercyofyourmachine'sdefinitionsofvarious operationssuchastypecasting,atof(),andfloating-point outputwithsprintf(). Ifyourstdiorequiresaseekoreofbetweenreadsandwritesona particularstream,sodoesPerl.(Thisdoesn'tapplytosysread() andsyswrite().) Whilenoneofthebuilt-indatatypeshaveanyarbitrarysizelimits (apartfrommemorysize),therearestillafewarbitrarylimits:a givenvariablenamemaynotbelongerthan251characters.Linenumbers displayedbydiagnosticsareinternallystoredasshortintegers, sotheyarelimitedtoamaximumof65535(highernumbersusuallybeing affectedbywraparound). Youmaymailyourbugreports(besuretoincludefullconfiguration informationasoutputbythemyconfigprogramintheperlsource tree,orby"perl-V")[email protected]'vesucceeded incompilingperl,theperlbugscriptintheutils/subdirectory canbeusedtohelpmailinabugreport. PerlactuallystandsforPathologicallyEclecticRubbishLister,but don'ttellanyoneIsaidthat.   NOTES ThePerlmottois``There'smorethanonewaytodoit.''Divining howmanymoreisleftasanexercisetothereader. ThethreeprincipalvirtuesofaprogrammerareLaziness, Impatience,andHubris.SeetheCamelBookforwhy.  Index NAME SYNOPSIS GETTINGHELP Overview Tutorials ReferenceManual InternalsandCLanguageInterface Miscellaneous Language-Specific Platform-Specific StubsforDeletedDocuments DESCRIPTION AVAILABILITY ENVIRONMENT AUTHOR FILES SEEALSO DIAGNOSTICS BUGS NOTES