In computing , Common Gateway Interface ( CGI ) is an interface specification that enables web servers to execute an external program to process HTTP or HTTPS user requests.
83-473: Such programs are often written in a scripting language and are commonly referred to as CGI scripts , but they may include compiled programs. A typical use case occurs when a web user submits a web form on a web page that uses CGI. The form's data is sent to the web server within an HTTP request with a URL denoting a CGI script. The web server then launches the CGI script in a new computer process , passing
166-446: A Perl 4 binary with Oracle Call Interface compiled in. This has however since been replaced by a library (Perl Module), DBD::Oracle . Other complex and task-oriented applications may incorporate and expose an embedded programming language to allow their users more control and give them more functionality than can be available through a user interface, no matter how sophisticated. For example, Autodesk Maya 3D authoring tools embed
249-517: A URL that it serves as a reference to a CGI script. A common convention is to have a cgi-bin/ directory at the base of the directory tree and treat all executable files within this directory (and no other, for security) as CGI scripts. When a Web browser requests a URL that points to a file within the CGI directory (e.g., http://example.com/cgi-bin/printenv.pl/with/additional/path?and=a&query=string ), then, instead of simply sending that file ( /usr/local/apache/htdocs/cgi-bin/printenv.pl ) to
332-750: A Windows Script Host engine (VBScript, JScript and VBA by default in Windows and third-party engines including implementations of Rexx, Perl, Tcl, Python, XSLT, Ruby, Modern Pascal, Delphi , and C). A majority of applications can access and use operating system components via the object models or its own functions. Other devices like programmable calculators may also have glue languages; the operating systems of PDAs such as Windows CE may have available native or third-party macro tools that glue applications together, in addition to implementations of common glue languages—including Windows NT , DOS , and some Unix shells , Rexx, Modern Pascal, PHP, and Perl. Depending upon
415-525: A bytecode interpreter . npm is the pre-installed package manager for the Node.js server platform. It installs Node.js programs from the npm registry, organizing the installation and management of third-party Node.js programs. Node.js registers with the operating system so the OS notifies it of asynchronous I/O events such as new connections. Within the Node.js runtime, events trigger callbacks and each connection
498-408: A script is a relatively short and simple set of instructions that typically automate an otherwise manual process. The act of writing a script is called scripting . Scripting language or script language describes a programming language that is used for scripting. Originally, scripting was limited to automating an operating system shell and languages were relatively simple. Today, scripting
581-418: A "common" language, the user gets the advantage of being able to transfer skills from application to application. A more generic alternative is simply to provide a library (often a C library) that a general-purpose language can use to control the application, without modifying the language for the specific domain. JavaScript began as and primarily still is a language for scripting inside web browsers ; however,
664-487: A Web server creates a new CGI process for handling it and destroys the CGI process after the HTTP request has been handled. Creating and destroying a process can consume more CPU time and memory resources than the actual work of generating the output of the process, especially when the CGI program still needs to be interpreted by a virtual machine. For a high number of HTTP requests, the resulting workload can quickly overwhelm
747-741: A client, various alternatives were developed. In 1993, the National Center for Supercomputing Applications (NCSA) team wrote the specification for calling command line executables on the www-talk mailing list. The other Web server developers adopted it, and it has been a standard for Web servers ever since. A work group chaired by Ken Coar started in November 1997 to get the NCSA definition of CGI more formally defined. This work resulted in RFC 3875, which specified CGI Version 1.1. Specifically mentioned in
830-463: A computer program, the shell. Calvin Mooers in his TRAC language is generally credited with inventing command substitution , the ability to embed commands in scripts that, when interpreted, insert a character string into the script. Multics calls these active functions . Louis Pouzin wrote an early processor for command scripts called RUNCOM for CTSS around 1964. Stuart Madnick at MIT wrote
913-515: A function: escape_shell_cmd() . The function was supposed to sanitize its argument, which came from user input and then pass the input to the Unix shell, to be run in the security context of the Web server. The script did not correctly sanitize all input and allowed new lines to be passed to the shell, which effectively allowed multiple commands to be run. The results of these commands were then displayed on
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#1732791318344996-401: A general-purpose language. A scripting language may lack the functionality to write complex applications. Typically, a script starts executing at the first line of code whereas an application typically starts at a special point in the code called the entry point . For example, Java is not script-like since an application starts at the function named main which need not be at the top of
1079-399: A high level of abstraction, or as a control language , particularly for job control languages on mainframes. The term scripting language is sometimes used in a wider sense, to refer to dynamic high-level programming languages in general. Some are strictly interpreted languages , while others use a form of compilation. In this context, the term script refers to a small program in such
1162-480: A language for writing extensions to the browser itself, and several standard embedded languages for controlling the browser, including JavaScript (a dialect of ECMAScript ) or XUL . Scripting languages can be categorized into several different types, with a considerable degree of overlap among the types. Scripting is often contrasted with system programming , as in Ousterhout's dichotomy or " programming in
1245-470: A language; typically, contained in a single file, and no larger than a few thousand lines of code. The scope of scripting languages ranges from small to large, and from highly domain-specific language to general-purpose programming languages . A language may start as small and highly domain-specific and later develop into a portable and general-purpose language; conversely, a general-purpose language may later develop special domain-specific dialects. Script
1328-550: A long-term support release cycle. By 2016, the io.js website recommended returning to Node.js and announced no further io.js releases, effectively ending the fork and solidifying the merger's success. In 2019, the JS Foundation and Node.js Foundation merged to form the OpenJS Foundation . On September 6, 2023, Node.js 20.6.0 was released. The update brought the addition of built-in support for .env files,
1411-483: A macro language built into the editor, e.g., The SemWare Editor (TSE), vi improved (VIM), or using an external implementation, e.g., XEDIT , or both, e.g., KEDIT . Sometimes text editors and edit macros are used under the covers to provide other applications, e.g., FILELIST and RDRLIST in CMS . A major class of scripting languages has grown out of the automation of job control , which relates to starting and controlling
1494-509: A native Windows version of Node.js. The first Node.js build supporting Windows was released in July 2011. In January 2012, Dahl yielded management of the project to npm creator Isaac Schlueter. In January 2014, Schlueter announced that Timothy J. Fontaine would lead the project. In December 2014, Fedor Indutny created io.js, a fork of Node.js created because of dissatisfaction with Joyent's governance as an open-governance alternative with
1577-475: A scripting language for IBM's CP/CMS in 1966. He originally called this processor COMMAND, later named EXEC . Multics included an offshoot of CTSS RUNCOM, also called RUNCOM. EXEC was eventually replaced by EXEC 2 and REXX . Languages such as Tcl and Lua were specifically designed as general-purpose scripting languages that could be embedded in any application. Other languages such as Visual Basic for Applications (VBA) provided strong integration with
1660-539: A scripting language, notably the Google Chrome T-rex game. Early mainframe computers (in the 1950s) were non-interactive, instead using batch processing . IBM's Job Control Language (JCL) is the archetype of languages used to control batch processing. The first interactive shells were developed in the 1960s to enable remote operation of the first time-sharing systems, and these used shell scripts , which controlled running computer programs within
1743-649: A separate technical committee. The goal was to enable a structure that would be more receptive to community input, including the updating of io.js with the latest Google V8 JavaScript engine releases, diverging from Node.js's approach at that time. The Node.js Foundation, formed to reconcile Node.js and io.js under a unified banner, was announced in February 2015. The merger was realized in September 2015 with Node.js v0.12 and io.js v3.3 combining into Node v4.0. This merge brought V8 ES6 features into Node.js and started
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#17327913183441826-503: A simplified model that uses callbacks to signal the completion of a task. Node.js connects the ease of a scripting language (JavaScript) with the power of Unix network programming. Node.js was built on top of Google's V8 JavaScript engine since it was open-sourced under the BSD license , and it contains comprehensive support for fundamental protocols such as HTTP , DNS and TCP . JavaScript's existing popularity made Node.js accessible to
1909-476: A single programming language , as opposed to using different languages for the server- versus client-side programming. Node.js has an event-driven architecture capable of asynchronous I/O . These design choices aim to optimize throughput and scalability in web applications with many input/output operations, as well as for real-time Web applications (e.g., real-time communication programs and browser games ). The Node.js distributed development project
1992-447: A single application. A number of languages have been designed for the purpose of replacing application-specific scripting languages by being embeddable in application programs. The application programmer (working in C or another systems language) includes "hooks" where the scripting language can control the application. These languages may be technically equivalent to an application-specific extension language but when an application embeds
2075-402: A specific general-purpose language (e.g. QuakeC , modeled after C), they have custom features that distinguish them. Emacs Lisp , while a fully formed and capable dialect of Lisp , contains many special features that make it most useful for extending the editing functions of Emacs. An application-specific scripting language can be viewed as a domain-specific programming language specialized to
2158-581: A substantial amount of logic is written in script, it is better characterized as simply another software component, not "glue". Glue languages are especially useful for writing and maintaining: Glue language examples: Macro languages exposed to operating system or application components can serve as glue languages. These include Visual Basic for Applications , WordBasic , LotusScript , CorelScript , Hummingbird Basic, QuickScript, Rexx, SaxBasic , and WinWrap Basic. Other tools like AWK can also be considered glue languages, as can any language implemented by
2241-431: A task, it informs the main thread of this, which in turn, wakes up and executes the registered callback. A downside of this single-threaded approach is that Node.js does not allow vertical scaling by increasing the number of CPU cores of the machine it is running on without using an additional module, such as cluster, StrongLoop Process Manager, or pm2. However, developers can increase the default number of threads in
2324-441: A touch-activated screen. These languages could in principle be used to control any GUI application; but, in practice their use is limited because their use needs support from the application and from the operating system . There are a few exceptions to this limitation. Some GUI scripting languages are based on recognizing graphical objects from their display screen pixels . These GUI scripting languages do not depend on support from
2407-443: Is a subjective characterization that generally includes the following attributes. A script is usually not compiled – at least not its usual meaning. Generally, they are interpreted directly from source code or from bytecode or run as native after just-in-time compilation . A script is generally relatively short and simple. As there is no limit on size or complexity, script is subjective. A few lines of code without branching
2490-409: Is handled as a small heap allocation . Traditionally, relatively heavyweight OS processes or threads handled each connection. Node.js uses an event loop for concurrent I/O, instead of processes or threads. In contrast to other event-driven servers, Node.js's event loop does not need to be called explicitly. Instead, callbacks are defined, and the server automatically enters the event loop at the end of
2573-443: Is more pervasive and some languages include modern features that allow them to be used for application development as well as scripting. A scripting language can be a general purpose language or a domain-specific language for a particular environment. When embedded in an application, it may be called an extension language . A scripting language is sometimes referred to as very high-level programming language if it operates at
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2656-405: Is often used to process input information from the user and produce the appropriate output. An example of a CGI program is one implementing a wiki . If the user agent requests the name of an entry, the Web server executes the CGI program. The CGI program retrieves the source of that entry's page (if one exists), transforms it into HTML , and prints the result. The Web server receives the output from
2739-415: Is probably considered a script. A codebase of multiple files, that performs sophisticated user or hardware interface or complicated algorithms or multiprogramming is probably not considered a script. A script usually automates a task that would otherwise be performed by a person in a more manual way. A language that is primarily intended for scripting generally has limited capabilities compared to
2822-544: Is released, the previous even version undergoes transition to Long Term Support (LTS), which gives that version 12 months of active support from the date it is designated LTS. After these 12 months expire, an LTS release receives an additional 18 months of maintenance support. An active version receives non-breaking backports of changes a few weeks after they land in the current release. A maintenance release receives only critical fixes and documentation updates. The LTS Working Group manages strategy and policy in collaboration with
2905-538: Is similar to Java Native Interface . In 2015, various branches of the greater Node.js community began working under the vendor-neutral Node.js Foundation. The stated purpose of the organization "is to enable widespread adoption and help accelerate development of Node.js and other related modules through an open governance model that encourages participation, technical contribution, and a framework for long-term stewardship by an ecosystem invested in Node.js' success." The Node.js Foundation Technical Steering Committee (TSC)
2988-402: Is stored at /usr/local/apache/htdocs/ in the local file system (its document root ), then the web server will respond to a request for http://www.example.com/index.html by sending to the browser a copy of the file /usr/local/apache/htdocs/index.html (if it exists). For pages constructed on the fly, the server software may defer requests to separate programs and relay the results to
3071-1037: Is that most functions in PHP block until completion (commands execute only after previous commands finish), while Node.js functions are non-blocking (commands execute concurrently and use callbacks to signal completion or failure), thus opening up new attack surfaces that are inherently absent in most web server applications. Node.js is officially supported by Linux , macOS and Microsoft Windows 8.1 and Server 2012 (and later), with Tier 2 support for SmartOS and IBM AIX and experimental support for FreeBSD . OpenBSD also works, and LTS versions are available for IBM i (AS/400). The source code may also be built on similar operating systems that are not officially supported, such as NonStop OS and Unix servers. Node.js enables development of fast web servers in JavaScript using event-driven programming . Developers can create scalable servers without using threading by using
3154-558: Is the technical governing body of the Node.js Foundation. The TSC is responsible for the core Node.js repo as well as dependent and adjacent projects. Generally the TSC delegates the administration of these projects to working groups or committees. The LTS group that manages long term supported releases is one such group. Other current groups include Website, Streams, Build, Diagnostics, i18n, Evangelism, Docker, Addon API, Benchmarking, Post-mortem, Intl, Documentation, and Testing. In August 2017,
3237-476: The Maya Embedded Language , or Blender which uses Python to fill this role. Some other types of applications that need faster feature addition or tweak-and-run cycles (e.g. game engines ) also use an embedded language. During the development, this allows them to prototype features faster and tweak more freely, without the need for the user to have intimate knowledge of the inner workings of
3320-520: The V8 JavaScript engine , and executes JavaScript code outside a web browser . Node.js lets developers use JavaScript to write command line tools and for server-side scripting . The ability to run JavaScript code on the server is often used to generate dynamic web page content before the page is sent to the user's web browser. Consequently, Node.js represents a "JavaScript everywhere" paradigm , unifying web-application development around
3403-1099: The web-development community . There are thousands of open-source libraries for Node.js, most of which are hosted on the npm website. Multiple developer conferences and events are held that support the Node.js community, including NodeConf, Node Interactive and Node Summit, as well as a number of regional events. The open-source community has developed web frameworks to accelerate the development of applications. Such frameworks include Express.js , Socket.IO , Sails.js , Next.js and Meteor . Various packages have also been created for interfacing with other languages or runtime environments such as Microsoft .NET . Modern desktop IDEs provide editing and debugging features specifically for Node.js applications. Such IDEs include Atom , Brackets , JetBrains WebStorm , Microsoft Visual Studio (with Node.js Tools for Visual Studio, or TypeScript with Node definitions ), NetBeans , Nodeclipse Enide Studio ( Eclipse -based) and Visual Studio Code . Some online IDEs also support Node.js, such as Codeanywhere , Eclipse Che , Cloud9 IDE and
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3486-656: The API that partially alleviate the problem. They simplify interfaces, but as a side effect they may also introduce complexity which maintainers have to deal with. Even though the core functionality of Node.js resides in a JavaScript built-in library, modules written in C++ can be used to enhance capabilities and to improve performance of applications. In order to produce such modules one needs to have an appropriate C++ compiler and necessary headers (the latter are typically shipped with Node.js itself), e.g., gcc , clang or MSVC++ . The N-API
3569-417: The CGI program and transmits it to the user agent. Then if the user agent clicks the "Edit page" button, the CGI program populates an HTML textarea or other editing control with the page's contents. Finally if the user agent clicks the "Publish page" button, the CGI program transforms the updated HTML into the source of that entry's page and saves it. CGI programs run, by default, in the security context of
3652-526: The HTTP environment. For instance, if a slash and additional directory name(s) are appended to the URL immediately after the name of the script (in this example, /with/additional/path ), then that path is stored in the PATH_INFO environment variable before the script is called. If parameters are sent to the script via an HTTP GET request (a question mark appended to the URL, followed by param=value pairs; in
3735-459: The N-API relies on internal C/C++ Node.js and V8 objects requiring users to import ( #include ) Node.js specific headers into their native source code. As the Node.js API is subject to breaking changes at a binary level, modules have to be built and shipped against specific Node.js versions to work properly. To address the issue, third parties have introduced open-sourced С/С++ wrappers on top of
3818-1034: The OS version, WSH and the default script engines (VBScript and JScript) are available. Programmable calculators can be programmed in glue languages in three ways. For example, the Texas Instruments TI-92 , by factory default can be programmed with a command script language. Inclusion of the scripting and glue language Lua in the TI-NSpire series of calculators could be seen as a successor to this. The primary on-board high-level programming languages of most graphing calculators (most often Basic variants, sometimes Lisp derivatives, and more uncommonly, C derivatives) in many cases can glue together calculator functions—such as graphs, lists, matrices, etc. Third-party implementations of more comprehensive Basic version that may be closer to variants listed as glue languages in this article are available—and attempts to implement Perl, Rexx, or various operating system shells on
3901-483: The RFC are the following contributors: Historically CGI programs were often written using the C programming language . RFC 3875 "The Common Gateway Interface (CGI)" partially defines CGI using C, in saying that environment variables "are accessed by the C library routine getenv() or variable environ". The name CGI comes from the early days of the Web, where webmasters wanted to connect legacy information systems such as databases to their Web servers. The CGI program
3984-484: The TI and HP graphing calculators are also mentioned. PC-based C cross-compilers for some of the TI and HP machines used with tools that convert between C and Perl, Rexx, AWK, and shell scripts to Perl, Modern Pascal, VBScript to and from Perl make it possible to write a program in a glue language for eventual implementation (as a compiled program) on the calculator. A number of text editors support macros written either using
4067-567: The Technical Steering Committee of the Node.js Foundation. Node.js is a JavaScript runtime environment that processes incoming requests in a loop, called the event loop . Node.js uses libuv under the hood to handle asynchronous events. Libuv is an abstraction layer for network and file system functionality on both Windows and POSIX -based systems such as Linux, macOS , OSS on NonStop , and Unix. Node.js relies on nghttp2 for HTTP support. As of version 20, Node.js uses
4150-414: The Web browser, the HTTP server runs the specified script and passes the output of the script to the Web browser. That is, anything that the script sends to standard output is passed to the Web client instead of being shown in the terminal window that started the web server. Another popular convention is to use filename extensions ; for instance, if CGI scripts are consistently given the extension .cgi ,
4233-451: The Web server can be configured to interpret all such files as CGI scripts. While convenient, and required by many prepackaged scripts, it opens the server to attack if a remote user can upload executable code with the proper extension. The CGI specification defines how additional information passed with the request is passed to the script. The Web server creates a subset of the environment variables passed to it and adds details pertinent to
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#17327913183444316-532: The Web server. The computational overhead involved in CGI process creation and destruction can be reduced by the following techniques: The optimal configuration for any Web application depends on application-specific details, amount of traffic, and complexity of the transaction; these trade-offs need to be analyzed to determine the best implementation for a given task and time budget. Web frameworks offer an alternative to using CGI scripts to interact with user agents. Scripting language In computing,
4399-473: The Web server. If the security context of the Web server allowed it, malicious commands could be executed by attackers. This was the first widespread example of a new type of Web-based attack called code injection , where unsanitized data from Web users could lead to execution of code on a Web server. Because the example code was installed by default, attacks were widespread and led to a number of security advisories in early 1996. For each incoming HTTP request,
4482-407: The Web server. When first introduced a number of example scripts were provided with the reference distributions of the NCSA, Apache and CERN Web servers to show how shell scripts or C programs could be coded to make use of the new CGI. One such example script was a CGI program called PHF that implemented a simple phone book. In common with a number of other scripts at the time, this script made use of
4565-414: The ada library which provides up-to-date WHATWG URL compliance. As of version 19.5, Node.js uses the simdutf library for fast Unicode validation and transcoding. As of version 21.3, Node.js uses the simdjson library for fast JSON parsing. Node.js operates on a single-thread event loop , using non-blocking I/O calls, allowing it to support tens of thousands of concurrent connections without incurring
4648-475: The advent of graphical user interfaces, a specialized kind of scripting language emerged for controlling a computer. These languages interact with the same graphic windows, menus, buttons, and so on, that a human user would. They do this by simulating the actions of a user. These languages are typically used to automate user actions. Such languages are also called " macros " when control is through simulated key presses or mouse clicks, as well as tapping or pressing on
4731-443: The application or to rebuild it after each tweak (which can take a significant amount of time). The scripting languages used for this purpose range from the more common and more famous Lua and Python to lesser-known ones such as AngelScript and Squirrel . Node.js Node.js is a cross-platform , open-source JavaScript runtime environment that can run on Windows , Linux , Unix , macOS , and more. Node.js runs on
4814-445: The automation facilities of an underlying system. Embedding of such general-purpose scripting languages instead of developing a new language for each application also had obvious benefits, relieving the application developer of the need to code a language translator from scratch and allowing the user to apply skills learned elsewhere. Some software incorporates several different scripting languages. Modern web browsers typically provide
4897-520: The behavior of system programs (in this sense, one might think of shells as being descendants of IBM's JCL, or Job Control Language , which was used for exactly this purpose). Many of these languages' interpreters double as command-line interpreters such as the Unix shell or the MS-DOS COMMAND.COM . Others, such as AppleScript offer the use of English-like commands to build scripts. With
4980-728: The callback definition. Node.js exits the event loop when there are no further callbacks to be performed. Node.js supports WebAssembly and as of Node 14 has experimental support of WASI , the WebAssembly System Interface. Node.js provides a way to create "add-ons" via a C -based API called N-API, which can be used to produce loadable (importable) .node modules from source code written in C/C++. The modules can be directly loaded into memory and executed from within JS environment as simple CommonJS modules. The implementation of
5063-422: The code. The following code starts at main , then calls printHelloWorld which prints "Hello World". In contrast, the following Python code prints "Hello World" without the main function or other syntax such as a class definition required by Java. Scripts are often created or modified by the person executing them, but they are also often distributed, such as when large portions of games are written in
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#17327913183445146-477: The complexity of writing server applications. JavaScript is the only language that Node.js supports natively, but many compile-to-JS languages are available. As a result, Node.js applications can be written in CoffeeScript , Dart , TypeScript , ClojureScript and others. Node.js is primarily used to build network programs such as web servers. The most significant difference between Node.js and PHP
5229-466: The cost of thread context switching . The design of sharing a single thread among all the requests that use the observer pattern is intended for building highly concurrent applications, where any function performing I/O must use a callback . To accommodate the single-threaded event loop, Node.js uses the libuv library—which, in turn, uses a fixed-sized thread pool that handles some of the non-blocking asynchronous I/O operations. A thread pool handles
5312-554: The cross-platform nature of the runtime. The Rocket Turtle was chosen as the official Node.js mascot in February 2024 following a design contest. Node.js allows the creation of web servers and networking tools using JavaScript and a collection of "modules" that handle various core functionalities. Modules are provided for file system I/O, networking ( DNS , HTTP , TCP , TLS/SSL or UDP ), binary data (buffers), cryptography functions, data streams and other core functions. Node.js's modules use an API designed to reduce
5395-470: The document type (e.g. HTML, PDF, or plain text), et cetera. Initially, there were no standardized methods for data exchange between a browser, the HTTP server with which it was communicating and the scripts on the server that were expected to process the data and ultimately return a result to the browser. As a result, mutual incompatibilities existed between different HTTP server variants that undermined script portability . Recognition of this problem led to
5478-465: The example, ?and=a&query=string ), then those parameters are stored in the QUERY_STRING environment variable before the script is called. Request HTTP message body , such as form parameters sent via an HTTP POST request, are passed to the script's standard input . The script can then read these environment variables or data from standard input and adapt to the Web browser's request. CGI
5561-416: The execution of parallel tasks in Node.js. The main thread function call posts tasks to the shared task queue, which threads in the thread pool pull and execute. Inherently non-blocking system functions such as networking translate to kernel-side non-blocking sockets, while inherently blocking system functions such as file I/O run in a blocking way on their own threads. When a thread in the thread pool completes
5644-410: The form data to it. The CGI script passes its output, usually in the form of HTML , to the Web server, and the server relays it back to the browser as its response to the browser's request. Developed in the early 1990s, CGI was the earliest common method available that allowed a web page to be interactive. Due to a necessity to run CGI scripts in a separate process every time the request comes in from
5727-505: The inaugural European JSConf on November 8, 2009. Node.js combined Google 's V8 JavaScript engine, an event loop , and a low-level I/O API . In January 2010, a package manager was introduced for the Node.js environment called npm . The package manager allows programmers to publish and share Node.js packages , along with the accompanying source code, and is designed to simplify the installation, update and uninstallation of packages. In June 2011, Microsoft and Joyent implemented
5810-432: The large and programming in the small ". In this view, scripting is glue code , connecting software components , and a language specialized for this purpose is a glue language . Pipelines and shell scripting are archetypal examples of glue languages, and Perl was initially developed to fill this same role. Web development can be considered a use of glue languages, interfacing between a database and web server . But if
5893-550: The libuv thread pool. The server operating system (OS) is likely to distribute these threads across multiple cores. Another problem is that long-lasting computations and other CPU-bound tasks freeze the entire event-loop until completion. V8 is the JavaScript execution engine which was initially built for Google Chrome . It was then open-sourced by Google in 2008. Written in C++ , V8 compiles JavaScript source code to native machine code at runtime . As of 2016, it also includes Ignition,
5976-527: The operating system or application. When the GUI provides the appropriate interfaces, as in the IBM Workplace Shell , a generic scripting language, e.g. OREXX , can be used for writing GUI scripts. Application specific languages can be split in many different categories, i.e. standalone based app languages (executable) or internal application specific languages (postscript, xml, gscript as some of
6059-407: The requesting client (usually, a Web browser that displays the page to the end user). Such programs usually require some additional information to be specified with the request, such as query strings or cookies . Conversely, upon returning, the script must provide all the information required by HTTP for a response to the request: the HTTP status of the request, the document content (if available),
6142-539: The specification of how data exchange was to be carried out, resulting in the development of CGI. Web page-generating programs invoked by server software that adheres to the CGI specification are known as CGI scripts , even though they may actually have been written in a non-scripting language, such as C . The CGI specification was quickly adopted and continues to be supported by all well-known HTTP server packages, such as Apache , Microsoft IIS , and (with an extension) Node.js -based servers. An early use of CGI scripts
6225-572: The standardization of the language as ECMAScript has made it popular as a general-purpose embeddable language. In particular, the Mozilla implementation SpiderMonkey is embedded in several environments such as the Yahoo! Widget Engine . Other applications embedding ECMAScript implementations include the Adobe products Adobe Flash ( ActionScript ) and Adobe Acrobat (for scripting PDF files). Tcl
6308-441: The unflagging of import.meta.resolve , the introduction of a new node: module API register for module customization hooks and a new initialize hook. Additionally, the module customization load hook now supports CommonJS , and Node.js C++ add-ons have gained experimental support for cppgc (Oilpan), which is a C++ garbage collection library for V8. The Node.js logo features a green hexagon with overlapping bands to represent
6391-615: The visual flow editor in Node-RED . Node.js is supported across a number of cloud-hosting platforms such as Jelastic , Google Cloud Platform , AWS Elastic Beanstalk , Azure Web Apps and Joyent . New major releases of Node.js are cut from the GitHub main branch every six months. Even-numbered versions are cut in April and odd-numbered versions are cut in October. When a new odd version
6474-444: The widely distributed scripts, respectively implemented by Adobe, MS and Google) among others include an idiomatic scripting language tailored to the needs of the application user. Likewise, many computer game systems use a custom scripting language to express the programmed actions of non-player characters and the game environment. Languages of this sort are designed for a single application; and, while they may superficially resemble
6557-456: Was created as an extension language but has come to be used more frequently as a general-purpose language in roles similar to Python , Perl , and Ruby . On the other hand, Rexx was originally created as a job control language, but is widely used as an extension language as well as a general-purpose language. Perl is a general-purpose language, but had the Oraperl (1990) dialect, consisting of
6640-411: Was executed by the server and provided a common "gateway" between the Web server and the legacy information system. Traditionally a Web server has a directory which is designated as a document collection, that is, a set of files that can be sent to Web browsers connected to the server. For example, if a web server has the fully-qualified domain name www.example.com , and its document collection
6723-403: Was led by Dahl and later sponsored by Joyent . Dahl criticized the limited capability of Apache HTTP Server to handle many (10,000+) concurrent connections, as well as the dominant programming paradigm of sequential programming, in which applications could block entire processes or cause the creation of multiple execution stacks for simultaneous connections. Dahl demonstrated the project at
6806-613: Was previously governed by the Node.js Foundation, and has now merged with the JS Foundation to form the OpenJS Foundation . OpenJS Foundation is facilitated by the Linux Foundation 's Collaborative Projects program. Node.js was initially written by Ryan Dahl in 2009, about 13 years after the introduction of the first server-side JavaScript environment, Netscape's LiveWire Pro Web. The initial release supported only Linux and Mac OS X. Its development and maintenance
6889-534: Was to process forms. In the beginning of HTML, HTML forms typically had an "action" attribute and a button designated as the "submit" button. When the submit button is pushed the URI specified in the "action" attribute would be sent to the server with the data from the form sent as a query string. If the "action" specifies a CGI script then the CGI script would be executed, the script in turn generating an HTML page. A Web server that supports CGI can be configured to interpret
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