scripting language designed web development general purpose programming language originally created reference implementation produced originally stood stands code embedded code combination web template systems web content management systems web code usually processed interpreter implemented module web common gateway interface cgi web combines results interpreted executed code type data including images generated web page code executed command line interface implement standalone graphical applications standard interpreter powered free software released widely ported deployed web operating system platform free charge language evolved written formal specification standard leaving canonical interpreter facto standard work gone create formal specification 2010s increased efforts code sharing applications projects form initiatives composer manager history early history development began wrote cgi programs maintain personal extended work web forms communicate called implementation personal home page forms interpreter build simple dynamic web applications accelerate bug reporting improve code initially announced release personal home page tools version discussion group june release basic functionality included like form handling ability resembled simpler limited consistent early intended new programming language grew noting retrospect don know stop intent write programming language absolutely idea write programming language kept adding logical step way development team began form months work beta testing officially released november fact originally designed instead developed led inconsistent naming functions inconsistent ordering parameters cases function names chosen match lower level libraries wrapping early versions length function names internally function names chosen improve distribution values rewrote formed base changing language acronym public testing began official launch came june started new rewrite core producing founded israel powered engine released august branch reached version longer development security updates released july released powered new engine included new features improved support object oriented programming extension defines lightweight consistent interface numerous performance enhancements stable version development late static binding missing added version high profile open source projects ceased support new code february initiative provided consortium developers promoting transition time available existing bit bit operating systems building source code pre built versions available microsoft windows bit builds requiring windows bit compatibility mode bit windows platform version bit builds available microsoft windows received mixed reviews lacking native support core language level project headed initiated bring native support library representing text strings internally cause major changes language user code planned release version language major features development shortage developers understood necessary changes performance problems arising conversion rarely web context led delays project result release created features ported notably march project current form officially abandoned release prepared containing remaining features traits closure binding initial hopes new plan formed integration adopted new major version developed numbered numbering version involved debate experiment released articles book titles referenced caused confusion new release reuse vote chosen foundation branch originally dubbed generation authored aimed performance engine retaining near complete language compatibility july based served main suite project showed increase performance changes expected easier improve performance future compact data structures changes seen better suited successful migration time significant changes reworked called engine succeeding major internal changes receive new major version number minor release according release process major versions allowed break backward compatibility code presented opportunity improvements require backward compatibility breaks particular involved following changes level legacy error mechanisms replaced modern object oriented exceptions variable reworked internally consistent complete allowing use operators arbitrary meaningful left hand expressions support legacy style methods behavior statement changed predictable classes built returned failure changed throw exception instead consistency application programming extensions removed core notably legacy extension behavior list operator changed remove support strings support legacy style code script language script removed oversight allowing switch statement multiple default clauses fixed support number support implicit conversions strings number types removed left shift right shift operators changed behave consistently platforms conversions floating point numbers implemented consistently platforms included new language features notably introduces return type functions complement existing type support types float string return type release history beginning june implemented timeline release new versions system release occur month year minor release occur include new features minor release supported years security bug followed year security total year release process minor release new features small self contained introduced minor release year release process mascot mascot project blue elephant logo designed differently colored toy form following hello world program written code embedded document requirement exists code embedded simplest version written like closing tag omitted preferred files containing pure code interpreter code outside processed text subject control structures described code common open close sections shortened form exists short makes script files portable support disabled local configuration discouraged recommendation use echo short tag prior short echo works short open tag configuration setting enabled later available purpose separate code content code form documents creates correctly formed processing instructions means resulting mixture code file formed dollar symbol type need specified advance introduced type allows functions force parameters objects specific class functions type hints types string unlike function class names variable names case sensitive double quoted strings provide ability variable value string treats manner free form language statements terminated types comment marks block comments line comments echo statement facilities provides output text web terms language similar style conditions loops function returns similar languages java data types stores platform dependent range bit bit signed equivalent language long type unsigned converted signed values certain situations behavior different programming languages assigned positive negative floating point numbers stored platform specific range specified floating point forms scientific native type similar native types java type conversion rules non zero values interpreted true zero false data type represents variable value allowed value data type resource type represent references resources external sources typically created functions particular extension processed functions extension examples include file image database resources contain elements type handle including resources objects order preserved lists values keys values supports strings single quotes double quotes attempts solve standard problems efficient data access classes functions defines large array functions core language available extensions functions documented online documentation built library wide variety naming conventions associated inconsistencies described history custom functions defined developer output sample program currently years old lieu function functions referenced string containing manner normal functions example function tables user defined functions created time functions defined inside code blocks permitting run time decision function defined function exists function determines function given defined function calls use exception zero argument class functions called operator new case optional support anonymous functions exist create function exists merely thin allows normal functions created program execution added define anonymous function closure capture surrounding scope example function creates closure passed argument use imports variable context takes additional argument returns created closure function class object meaning stored variable passed functions etc unusually language supports type function parameters enforced supported classes float string types type function return types expressed placing type list parameters preceded example function earlier example types like default type follow weak principles example type allow strings passed function convert strict mode conversions function calls returns file object oriented programming basic object oriented programming functionality added improved allowed gain making creative tasks easier programmers language object handling completely rewritten expanding feature set enhancing performance previous versions objects handled like value types method code heavy use reference wanted modify object passed creating copy new approach objects referenced handle value introduced private protected member methods abstract classes final classes abstract methods final methods introduced standard way declaring similar object oriented languages standard exception handling model furthermore added allowed multiple implemented special allow objects interact system objects implementing array objects implementing language construct virtual table feature engine static bound instead reference time developer creates copy object reserved word clone engine check clone method defined default clone copy object properties clone method defined responsible setting necessary properties created object convenience engine supply function imports properties source object programmer start value replica source object properties need changed following basic example object oriented programming visibility properties methods defined public private protected default public var var synonym public items declared public accessed protected limits access inherited classes class defines item private limits visibility class defines item objects type access private protected members instance member visibility features described highly useful described best irrelevant worst positively harmful original complete widely implementation powered known simply unofficially referred engine source code fly internal format execute works interpreter reference implementation formal specification define complex nuanced defined works difficult competing offer complete compatibility single request script execution model fact engine interpreter leads result products developed help improve performance order speed execution time source code time web page accessed scripts deployed engine internal format works compiled form script shared memory avoid overhead compiling code time script runs built version example widely available extension popular implementation developed support compilation offer performance benefits expense lacking compatibility alternative include following developed facebook available open source converts code high level commonly known intermediate language translated machine code time resulting performance improvements virtual machine designed run dynamic languages efficiently transforms source code intermediate representation translated executed virtual machine developed facebook available open source transforms scripts code resulting code reducing load early facebook favor multiple reasons including deployment difficulties lack support language including create function licensing free software released products derived software called appear prior written permission group indicate software works conjunction saying instead calling restriction use makes incompatible incompatible advertising clause similar original license development community includes free open source libraries source distribution uses resulting builds fundamentally internet aware system built file transfer protocol database including embedded database numerous functions familiar programmers family available standard builds allows developers write extensions add functionality language extensions compiled loaded numerous extensions written add support windows process management like operating systems strings popular compression formats features available extensions include integration dynamic generation images content layer speech synthesis language core functions dealing strings implemented extensions project extensions language projects provide ability extensions created high level language compiled native extensions approach instead writing extensions directly development extensions reduces time required programming testing consists people provides based exam programmers certified developers installation configuration primary ways adding support web native web module cgi direct module interface called supported web including defunct web support internet application programming interface microsoft web module interface module support web cgi case web use cgi process requests files process manager alternative implementation bundled official distribution version compared older implementation contains additional features useful heavily loaded web command line scripting command line interface needed supports main focus developing shell applications differences share behaviors direct module interface called different web case windows provided form file called module functions provides interface web implemented form understands form known different kinds web extensions example addition listed language include cgi command line interface writing graphical user interface applications extension included official distribution extension versions newer common way installing compiling source code installed cloud environments software development kits provided cloud specific features example provides windows windows numerous configuration options supported affecting core features extensions configuration file searched different locations depending way configuration file split sections configuration options set web configuration use general purpose scripting language especially suited web development case generally runs web code requested file executed usually create dynamic web page content dynamic images websites command line scripting client graphical user interface applications deployed web operating systems platforms database management systems web hosting providers support use clients available free charge provides complete source code users build extend use acts primarily filter taking input file stream containing text instructions stream data commonly output data image audio formats input produce processing giving improved performance interpreter predecessor originally designed create dynamic web pages focuses mainly scripting similar scripting languages provide dynamic content web client microsoft pages attracted development software provide building blocks design structure promote rapid application development include offering features similar web lamp architecture popular web industry way deploying web applications commonly bundle alongside refer mix similar packages available windows letter standing respective operating system provided mac base install users packages seek simpler installation mechanism easily kept date april million internet domains web services hosted installed recorded popular module october programming language websites programming language known february percentage reached open source software enterprises web content management systems written include publish user facing portion facebook specific advanced usage scenarios offers defined documented way writing custom extensions extending language form additional libraries extensions providing way improving execution speed critical room improvements true compiled language offers defined ways software projects way easily internal scripting language project providing tight project specific internal data structures received mixed reviews lacking support core language level threads possible extension january million websites sampled installed million web security listed linked historically listed database linked technical security flaws language core libraries frequent total applies programs listed recognizing programmers mistakes languages include checking automatically detect lack input issues feature developed inclusion release rejected times past advanced protection patches patch especially designed web hosting environments certain language features configuration parameters primarily default values settings applications prone security issues magic quotes register configuration best known parameters opening path security allowing attacker set value global variable interfere execution script support magic quotes register removed example settings vulnerability comes failing disable execution engine configuration directive uploaded images stored leaving default settings result execution code embedded uploaded images leaving enabled dynamic loading extensions enable configuration directive shared web hosting environment lead security issues implied type conversions result incompatible values treated identical programmer intent lead security issues example result comparison comparison true compared value treated scientific having value zero feature resulted compared instead function identity operator results false analysis website published frequently technique exploitation file inclusion vulnerability related insecure usage functions include require allow
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