Perl predefined variables - Perldoc Browser

CONTENTS. General Variables; Variables related to regular expressions; Variables related to filehandles. Variables related to formats. 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Variablesrelatedtoformats ErrorVariables Variablesrelatedtotheinterpreterstate Deprecatedandremovedvariables Fulldocumentationofpredefinedvariables:perlvar #GeneralVariables $_-Thedefaultinputandpattern-searchingspace @_-Withinasubroutinethearray@_containstheparameterspassedtothatsubroutine $"-Whenanarrayoranarraysliceisinterpolatedintoadouble-quotedstringorasimilarcontextsuchas/.../,itselementsareseparatedbythisvalue $$-TheprocessnumberofthePerlrunningthisscript $0-Containsthenameoftheprogrambeingexecuted $(-Therealgidofthisprocess $)-Theeffectivegidofthisprocess $-Theeffectiveuidofthisprocess $;-Thesubscriptseparatorformultidimensionalarrayemulation $a,$b-Specialpackagevariableswhenusingsort(),see"sort"inperlfunc %ENV-Thehash%ENVcontainsyourcurrentenvironment $]-Therevision,version,andsubversionofthePerlinterpreter,representedasadecimaloftheform5.XXXYYY,whereXXXistheversion/1e3andYYYisthesubversion/1e6 $^F-Themaximumsystemfiledescriptor,ordinarily2.Systemfiledescriptorsarepassedtoexec()edprocesses,whilehigherfiledescriptorsarenot @F-Thearray@Fcontainsthefieldsofeachlinereadinwhenautosplitmodeisturnedon @INC-Thearray@INCcontainsthelistofplacesthatthedoEXPR,require,oruseconstructslookfortheirlibraryfiles %INC-Thehash%INCcontainsentriesforeachfilenameincludedviathedo,require,oruseoperators $^I-Thecurrentvalueoftheinplace-editextension @ISA-Eachpackagecontainsaspecialarraycalled@ISAwhichcontainsalistofthatclass'sparentclasses,ifany $^M-Perlcanusethecontentsof$^Masanemergencymemorypoolafterdie()ing $^O-ThenameoftheoperatingsystemunderwhichthiscopyofPerlwasbuilt,asdeterminedduringtheconfigurationprocess %SIG-Thehash%SIGcontainssignalhandlersforsignals $^T-Thetimeatwhichtheprogrambeganrunning,insecondssincetheepoch(beginningof1970) $^V-Therevision,version,andsubversionofthePerlinterpreter,representedasaversionobject $^X-ThenameusedtoexecutethecurrentcopyofPerl,fromC'sargv[0]or(wheresupported)/proc/self/exe #Variablesrelatedtoregularexpressions $($1,$2,...)-Containsthesubpatternfromthecorrespondingsetofcapturingparenthesesfromthelastsuccessfulpatternmatch,notcountingpatternsmatchedinnestedblocksthathavebeenexitedalready @{^CAPTURE}-Anarraywhichexposesthecontentsofthecapturebuffers,ifany,ofthelastsuccessfulpatternmatch,notcountingpatternsmatchedinnestedblocksthathavebeenexitedalready $&-Thestringmatchedbythelastsuccessfulpatternmatch(notcountinganymatcheshiddenwithinaBLOCKoreval()enclosedbythecurrentBLOCK) ${^MATCH}-Thisissimilarto$&($MATCH)exceptthatitdoesnotincurtheperformancepenaltyassociatedwiththatvariable $`-Thestringprecedingwhateverwasmatchedbythelastsuccessfulpatternmatch,notcountinganymatcheshiddenwithinaBLOCKorevalenclosedbythecurrentBLOCK ${^PREMATCH}-Thisissimilarto$`($PREMATCH)exceptthatitdoesnotincurtheperformancepenaltyassociatedwiththatvariable $'-Thestringfollowingwhateverwasmatchedbythelastsuccessfulpatternmatch(notcountinganymatcheshiddenwithinaBLOCKoreval()enclosedbythecurrentBLOCK) ${^POSTMATCH}-Thisissimilarto$'($POSTMATCH)exceptthatitdoesnotincurtheperformancepenaltyassociatedwiththatvariable $+-Thetextmatchedbythehighestusedcapturegroupofthelastsuccessfulsearchpattern $^N-Thetextmatchedbytheusedgroupmost-recentlyclosed(i.e.thegroupwiththerightmostclosingparenthesis)ofthelastsuccessfulsearchpattern @+-Thisarrayholdstheoffsetsoftheendsofthelastsuccessfulsubmatchesinthecurrentlyactivedynamicscope %+-Similarto@+,the%+hashallowsaccesstothenamedcapturebuffers,shouldtheyexist,inthelastsuccessfulmatchinthecurrentlyactivedynamicscope @--$-[0]istheoffsetofthestartofthelastsuccessfulmatch %--Similarto%+,thisvariableallowsaccesstothenamedcapturegroupsinthelastsuccessfulmatchinthecurrentlyactivedynamicscope $^R-Theresultofevaluationofthelastsuccessful(?{code})regularexpressionassertion(seeperlre) ${^RE_COMPILE_RECURSION_LIMIT}-Thecurrentvaluegivingthemaximumnumberofopenbutunclosedparentheticalgroupstheremaybeatanypointduringaregularexpressioncompilation ${^RE_DEBUG_FLAGS}-Thecurrentvalueoftheregexdebuggingflags ${^RE_TRIE_MAXBUF}-Controlshowcertainregexoptimisationsareappliedandhowmuchmemorytheyutilize #Variablesrelatedtofilehandles $ARGV-Containsthenameofthecurrentfilewhenreadingfrom<> @ARGV-Thearray@ARGVcontainsthecommand-lineargumentsintendedforthescript ARGV-Thespecialfilehandlethatiteratesovercommand-linefilenamesin@ARGV ARGVOUT-Thespecialfilehandlethatpointstothecurrentlyopenoutputfilewhendoingedit-in-placeprocessingwith-i $,-Theoutputfieldseparatorfortheprintoperator $.-Currentlinenumberforthelastfilehandleaccessed $/-Theinputrecordseparator,newlinebydefault $\-Theoutputrecordseparatorfortheprintoperator $|-Ifsettononzero,forcesaflushrightawayandaftereverywriteorprintonthecurrentlyselectedoutputchannel ${^LAST_FH}-Thisread-onlyvariablecontainsareferencetothelast-readfilehandle #Variablesrelatedtoformats $^A-Thecurrentvalueofthewrite()accumulatorforformat()lines $^L-Whatformatsoutputasaformfeed $%-Thecurrentpagenumberofthecurrentlyselectedoutputchannel $--Thenumberoflinesleftonthepageofthecurrentlyselectedoutputchannel $:-Thecurrentsetofcharactersafterwhichastringmaybebrokentofillcontinuationfields(startingwith^)inaformat $=-Thecurrentpagelength(printablelines)ofthecurrentlyselectedoutputchannel $^-Thenameofthecurrenttop-of-pageformatforthecurrentlyselectedoutputchannel $~-Thenameofthecurrentreportformatforthecurrentlyselectedoutputchannel #ErrorVariables ${^CHILD_ERROR_NATIVE}-Thenativestatusreturnedbythelastpipeclose,backtick(``)command,successfulcalltowait()orwaitpid(),orfromthesystem()operator $^E-Errorinformationspecifictothecurrentoperatingsystem $^S-Currentstateoftheinterpreter $^W-Thecurrentvalueofthewarningswitch,initiallytrueif-wwasused,falseotherwise,butdirectlymodifiable ${^WARNING_BITS}-Thecurrentsetofwarningchecksenabledbytheusewarningspragma $!-Whenreferenced,$!retrievesthecurrentvalueoftheCerrnointegervariable %!-Eachelementof%!hasatruevalueonlyif$!issettothatvalue $?-Thestatusreturnedbythelastpipeclose,backtick(``)command,successfulcalltowait()orwaitpid(),orfromthesystem()operator $@-ThePerlerrorfromthelastevaloperator,i.e.thelastexceptionthatwascaught #Variablesrelatedtotheinterpreterstate $^C-Thecurrentvalueoftheflagassociatedwiththe-cswitch $^D-Thecurrentvalueofthedebuggingflags ${^GLOBAL_PHASE}-Thecurrentphaseoftheperlinterpreter $^H-Thisvariablecontainscompile-timehintsforthePerlinterpreter %^H-The%^Hhashprovidesthesamescopingsemanticas$^H ${^OPEN}-AninternalvariableusedbyPerlIO $^P-Theinternalvariablefordebuggingsupport ${^TAINT}-Reflectsiftaintmodeisonoroff ${^SAFE_LOCALES}-Reflectsifsafelocaleoperationsareavailabletothisperl(whenthevalueis1)ornot(thevalueis0) ${^UNICODE}-ReflectscertainUnicodesettingsofPerl ${^UTF8CACHE}-ThisvariablecontrolsthestateoftheinternalUTF-8offsetcachingcode ${^UTF8LOCALE}-ThisvariableindicateswhetheraUTF-8localewasdetectedbyperlatstartup #Deprecatedandremovedvariables $#-$#wasavariablethatcouldbeusedtoformatprintednumbers $*-$*wasavariablethatyoucouldusetoenablemultilinematching $[-Thisvariablestorestheindexofthefirstelementinanarray,andofthefirstcharacterinasubstring ${^ENCODING}-ItusedtoholdtheobjectreferencetotheEncodeobjectthatwasusedtoconvertthesourcecodetoUnicode ${^WIN32_SLOPPY_STAT}-Thisvariablenolongerhasanyfunction PerldocBrowserismaintainedbyDanBook(DBOOK).PleasecontacthimviatheGitHubissuetrackeroremailregardinganyissueswiththesiteitself,search,orrenderingofdocumentation. 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