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Perl Software
Perl is a high-level, general-purpose, interpreted, dynamic programming language. Though Perl is not officially an acronym, there are various backronyms in use, including "Practical Extraction and Reporting Language". Perl was developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions. Perl originally was not capitalized and the name was changed to being capitalized by the time Perl 4 was released. The latest release is Perl 5, first released in 1994. From 2000 to October 2019 a sixth version of Perl was in development; the sixth version's name was changed to Raku. Both languages continue to be developed independently by different development teams which liberally borrow ideas from each other. Perl borrows features from other programming languages including C, sh, AWK, and sed. It provides text processing facilities without the arbitrary data-length limits of man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multi-paradigm
Programming languages can be grouped by the number and types of Programming paradigm, paradigms supported. Paradigm summaries A concise reference for the programming paradigms listed in this article. * Concurrent programming language, Concurrent programming – have language constructs for concurrency, these may involve multi-threading, support for distributed computing, message passing, shared resources (including shared memory), or Futures and promises, futures ** Actor model, Actor programming – concurrent computation with ''actors'' that make local decisions in response to the environment (capable of selfish or competitive behaviour) * Constraint programming – relations between variables are expressed as constraints (or constraint networks), directing allowable solutions (uses constraint satisfaction or simplex algorithm) * Dataflow, Dataflow programming – forced recalculation of formulas when data values change (e.g. spreadsheets) * Declarative programming – describes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix Shell
A Unix shell is a Command-line_interface#Command-line_interpreter, command-line interpreter or shell (computing), shell that provides a command line user interface for Unix-like operating systems. The shell is both an interactive command language and a scripting language, and is used by the operating system to control the execution of the system using shell scripts. Users typically interact with a Unix shell using a terminal emulator; however, direct operation via serial hardware connections or Secure Shell are common for server systems. All Unix shells provide filename Wildcard character, wildcarding, Pipeline (Unix), piping, here documents, command substitution, Variable (programming), variables and control flow, control structures for Conditional (programming), condition-testing and iteration. Concept Generally, a ''shell'' is a program that executes other programs in response to text commands. A sophisticated shell can also change the environment in which other programs exe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regular Expression
A regular expression (shortened as regex or regexp), sometimes referred to as rational expression, is a sequence of characters that specifies a match pattern in text. Usually such patterns are used by string-searching algorithms for "find" or "find and replace" operations on strings, or for input validation. Regular expression techniques are developed in theoretical computer science and formal language theory. The concept of regular expressions began in the 1950s, when the American mathematician Stephen Cole Kleene formalized the concept of a regular language. They came into common use with Unix text-processing utilities. Different syntaxes for writing regular expressions have existed since the 1980s, one being the POSIX standard and another, widely used, being the Perl syntax. Regular expressions are used in search engines, in search and replace dialogs of word processors and text editors, in text processing utilities such as sed and AWK, and in lexical analysis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Gateway Interface
file:Common Gateway Interface logo.svg, The official CGI logo from the spec announcement 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. Such programs are often written in a scripting language and are commonly referred to as ''CGI scripts'', but they may include compiler, 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 a HTTP request with a URL denoting a CGI script. The web server then launches the CGI script in a new computer process, passing 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 HTTP response, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Expressive Power (computer Science)
In computer science, the expressive power (also called expressiveness or expressivity) of a language is the breadth of ideas that can be represented and communicated in that language. The more expressive a language is, the greater the variety and quantity of ideas it can be used to represent. For example, the Web Ontology Language expression language profile (OWL2 EL) lacks ideas (such as negation) that can be expressed in OWL2 RL (rule language). OWL2 EL may therefore be said to have less ''expressive power'' than OWL2 RL. These restrictions allow for more efficient ( polynomial time) reasoning in OWL2 EL than in OWL2 RL. So OWL2 EL trades some expressive power for more efficient reasoning (processing of the knowledge representation language). Information description The term ''expressive power'' may be used with a range of meaning. It may mean a measure of the ideas expressible in that language: * regardless of ease (''theoretical expressivity'') * concisely and readily ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
O'Reilly Media
O'Reilly Media, Inc. (formerly O'Reilly & Associates) is an American learning company established by Tim O'Reilly that provides technical and professional skills development courses via an online learning platform. O'Reilly also publishes books about programming and other technical content. Its distinctive brand features a woodcut of an animal on many of its book covers. The company was known as a popular tech conference organizer for more than 20 years before closing the live conferences arm of its business. Company Early days The company began in 1978 as a private consulting firm doing technical writing, based in the Cambridge, Massachusetts area. In 1984, it began to retain publishing rights on manuals created for Unix vendors. A few 70-page "Nutshell Handbooks" were well-received, but the focus remained on the consulting business until 1988. After a conference displaying O'Reilly's preliminary Xlib manuals attracted significant attention, the company began increas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Unix Commands
This is a list of the shell commands of the most recent version of the Portable Operating System Interface (POSIX) IEEE Std 1003.1-2024 which is part of the Single UNIX Specification (SUS). These commands are implemented in many shells on modern Unix, Unix-like and other operating systems. This list does not cover commands for all versions of Unix and Unix-like shells nor other versions of POSIX. See also * GNOME Core Applications * GNU Core Utilities * List of GNU packages * List of KDE applications * List of Unix daemons * Unix philosophy The Unix philosophy, originated by Ken Thompson, is a set of cultural norms and philosophical approaches to Minimalism (computing), minimalist, Modularity (programming), modular software development. It is based on the experience of leading devel ... * References External links IEEE Std 1003.1,2004 specificationsIEEE Std 1003.1,2008 specificationsIEEE Std 1003.1,2024 specifications– configurable list of equivalent pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scripting Language
In computing, a script is a relatively short and simple set of instructions that typically automation, automate an otherwise manual process. The act of writing a script is called scripting. A scripting language or script language is 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 is more pervasive and some languages include modern features that allow them to be used for Application software, application development as well as scripting. Overview 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 a high level of abstraction, or as a control language, particularly for job control languages on mainframes. The te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix
Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others. Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Berkeley ( BSD), Microsoft (Xenix), Sun Microsystems ( SunOS/ Solaris), HP/ HPE ( HP-UX), and IBM ( AIX). The early versions of Unix—which are retrospectively referred to as " Research Unix"—ran on computers such as the PDP-11 and VAX; Unix was commonly used on minicomputers and mainframes from the 1970s onwards. It distinguished itself from its predecessors as the first portable operating system: almost the entire operating system is written in the C programming language (in 1973), which allows U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backronym
A backronym is an acronym formed from an already existing word by expanding its letters into the words of a phrase. Backronyms may be invented with either serious or humorous intent, or they may be a type of false etymology or folk etymology. The word is a portmanteau of ''back'' and ''acronym''. A normal acronym is a word derived from the initial letter(s) of the words of a phrase, such as ''radar'' from "radio detection and ranging". By contrast, a backronym is "an acronym deliberately formed from a phrase whose initial letters spell out a particular word or words, either to create a memorable name or as a fanciful explanation of a word's origin". Many list of fictional espionage organizations, fictional espionage organizations are backronyms, such as SPECTRE (special executive for counterintelligence, terrorism, revenge and extortion) from the ''James Bond'' franchise. For example, the Amber Alert missing-child program was named after Amber Hagerman, a nine-year-old girl w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic Programming Language
A dynamic programming language is a type of programming language that allows various operations to be determined and executed at runtime. This is different from the compilation phase. Key decisions about variables, method calls, or data types are made when the program is running, unlike in static languages, where the structure and types are fixed during compilation. Dynamic languages provide flexibility. This allows developers to write more adaptable and concise code. For instance, in a dynamic language, a variable can start as an integer. It can later be reassigned to hold a string without explicit type declarations. This feature of dynamic typing enables more fluid and less restrictive coding. Developers can focus on the logic and functionality rather than the constraints of the language. Implementation Eval Some dynamic languages offer an '' eval'' function. This function takes a string or abstract syntax tree containing code in the language and executes it. If this code ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interpreter (computing)
In computer science, an interpreter is a computer program that directly executes instructions written in a programming or scripting language, without requiring them previously to have been compiled into a machine language program. An interpreter generally uses one of the following strategies for program execution: # Parse the source code and perform its behavior directly; # Translate source code into some efficient intermediate representation or object code and immediately execute that; # Explicitly execute stored precompiled bytecode made by a compiler and matched with the interpreter's virtual machine. Early versions of Lisp programming language and minicomputer and microcomputer BASIC dialects would be examples of the first type. Perl, Raku, Python, MATLAB, and Ruby are examples of the second, while UCSD Pascal is an example of the third type. Source programs are compiled ahead of time and stored as machine independent code, which is then linked at run-ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
