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78-677: Emacs has over 10,000 built-in commands and its user interface allows the user to combine these commands into macros to automate work. Implementations of Emacs typically feature a dialect of the Lisp programming language, allowing users and developers to write new commands and applications for the editor. Extensions have been written to, among other things, manage files , remote access , e-mail , outlines , multimedia , Git integration, RSS feeds, and collaborative editing , as well as implementations of ELIZA , Pong , Conway's Life , Snake , Dunnet , and Tetris . The original EMACS

156-438: A data serialisation format akin to, but simpler and more general than, well known ones such as XML , JSON , and YAML . In this way there is little difference in practice between customising existing features and writing new ones, both of which are accomplished in the same basic way. This is operatively different from most modern extensible editors, for instance such as VS Code , in which separate languages are used to implement

234-429: A free software alternative to the proprietary Gosling Emacs. GNU Emacs was initially based on Gosling Emacs, but Stallman's replacement of its Mocklisp interpreter with a true Lisp interpreter required that nearly all of its code be rewritten. This became the first program released by the nascent GNU Project. GNU Emacs is written in C and provides Emacs Lisp , also implemented in C, as an extension language. Version 13,

312-411: A human–machine interface ( HMI ) that typically interfaces machines with physical input hardware (such as keyboards, mice, or game pads) and output hardware (such as computer monitors , speakers, and printers ). A device that implements an HMI is called a human interface device (HID). User interfaces that dispense with the physical movement of body parts as an intermediary step between the brain and

390-450: A mode line at the bottom (usually displaying buffer name, the active modes and point position of the buffer among others). The bottom of every frame is used for output messages (then called 'echo area') and text input for commands (then called 'minibuffer'). In general, Emacs display elements (windows, frames, etc.) do not belong to any specific data or process. Buffers are not associated with windows, and multiple windows can be opened onto

468-477: A buffer but not bundled into a mode can be handled by simply focussing that buffer and live modifying the relevant data directly. Any interaction with the editor (like key presses or clicking a mouse button) is realized by evaluating Emacs Lisp code, typically a command , which is a function explicitly designed for interactive use. Keys can be arbitrarily redefined and commands can also be accessed by name; some commands evaluate arbitrary Emacs Lisp code provided by

546-458: A default line editor known as Tape Editor and Corrector (TECO). Unlike most modern text editors, TECO used separate modes in which the user would either add text, edit existing text, or display the document. One could not place characters directly into a document by typing them into TECO, but would instead enter a character ('i') in the TECO command language telling it to switch to input mode, enter

624-691: A different dialect of Lisp or a different programming language altogether. Although not all are still actively maintained, these clones include: Emacs is primarily a text editor and is designed for manipulating pieces of text, although it is capable of formatting and printing documents like a word processor by interfacing with external programs such as LaTeX , Ghostscript or a web browser. Emacs provides commands to manipulate and differentially display semantic units of text such as words , sentences , paragraphs and source code constructs such as functions . It also features keyboard macros for performing user-defined batches of editing commands. GNU Emacs

702-550: A general package of functions and commands relevant to a buffer's data and the way users might be interacting with it (e.g. editing source code in a specific language, editing hex , viewing the filesystem, interacting with git , etc.), and minor modes define subsidiary collections of functionality applicable across many major modes (such as auto-save-mode ). Minor modes can be toggled on or off both locally to each buffer as well as globally across all buffers, while major modes can only be toggled per-buffer. Any other data relevant to

780-420: A history going back to 1902 and had already become well-established in newsrooms and elsewhere by 1920. In reusing them, economy was certainly a consideration, but psychology and the rule of least surprise mattered as well; teleprinters provided a point of interface with the system that was familiar to many engineers and users. The widespread adoption of video-display terminals (VDTs) in the mid-1970s ushered in

858-408: A job to a batch machine involved first preparing a deck of punched cards that described a program and its dataset. The program cards were not punched on the computer itself but on keypunches , specialized, typewriter-like machines that were notoriously bulky, unforgiving, and prone to mechanical failure. The software interface was similarly unforgiving, with very strict syntaxes designed to be parsed by

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936-493: A multi-monitor setup, or a terminal frame connected via ssh from a remote system and a graphical frame displaying the same Emacs process via the local system's monitor. Just as buffers don't require windows, running Emacs processes do not require any frames, and one common usage pattern is to deploy Emacs as an editing server : running it as a headless daemon and connecting to it via a frame-spawning client. This server can then be made available in any situation where an editor

1014-438: A relatively heavy mnemonic load on the user, requiring a serious investment of effort and learning time to master. The earliest command-line systems combined teleprinters with computers, adapting a mature technology that had proven effective for mediating the transfer of information over wires between human beings. Teleprinters had originally been invented as devices for automatic telegraph transmission and reception; they had

1092-573: A result on magnetic tape or generate some data cards to be used in a later computation. The turnaround time for a single job often spanned entire days. If one was very lucky, it might be hours; there was no real-time response. But there were worse fates than the card queue; some computers required an even more tedious and error-prone process of toggling in programs in binary code using console switches. The very earliest machines had to be partly rewired to incorporate program logic into themselves, using devices known as plugboards . Early batch systems gave

1170-508: A stable, practical, and responsive editing environment for novice users. The main text editing data structure is the buffer , a memory region containing data (usually text) with associated attributes. The most important of these are: Modes , in particular, are an important concept in Emacs, providing a mechanism to disaggregate Emacs' functionality into sets of behaviours and keybinds relevant to specific buffers' data. Major modes provide

1248-493: A time). Because of its relatively large vocabulary of commands, Emacs features a long-established command language , to concisely express the keystrokes necessary to perform an action. This command language recognises the following shift and modifier keys: Ctrl , Alt , ⇧ Shift , Meta , Super , and Hyper . Not all of these may be present on an IBM-style keyboard, though they can usually be configured as desired. These are represented in command language as

1326-450: Is a graphical user interface (GUI), which is composed of a tactile UI and a visual UI capable of displaying graphics . When sound is added to a GUI, it becomes a multimedia user interface (MUI). There are three broad categories of CUI: standard , virtual and augmented . Standard CUI use standard human interface devices like keyboards, mice, and computer monitors. When the CUI blocks out

1404-461: Is a real-time display editor, as its edits are displayed onscreen as they occur. This is standard behavior for modern text editors but EMACS was among the earliest to implement this. The alternative is having to issue a distinct command to display text, (e.g. before or after modifying it). This was common in earlier (or merely simpler) line and context editors, such as QED (BTS, CTSS, Multics), ed (Unix), ED (CP/M), and Edlin (DOS). Almost all of

1482-418: Is a general principle in the design of all kinds of interfaces. It is based on the idea that human beings can only pay full attention to one thing at one time, leading to the conclusion that novelty should be minimized. If an interface is used persistently, the user will unavoidably develop habits for using the interface. The designer's role can thus be characterized as ensuring the user forms good habits. If

1560-600: Is also used to express the actions needed to invoke commands with no assigned shortcut: for example, the command scratch-buffer (which initialises a buffer in memory for temporary text storage and manipulation), when invoked by the user, will be reported back as M-x scra <return> , with Emacs scanning the namespace of contextually available commands to return the shortest sequence of keystrokes which uniquely lexicate it. Because Emacs predates modern standard terminology for graphical user interfaces , it uses somewhat divergent names for familiar interface elements. Buffers,

1638-400: Is better described as a direct neural interface . However, this latter usage is seeing increasing application in the real-life use of (medical) prostheses —the artificial extension that replaces a missing body part (e.g., cochlear implants ). In some circumstances, computers might observe the user and react according to their actions without specific commands. A means of tracking parts of

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1716-483: Is implemented through a scripting language called Emacs Lisp . Because about 70% of GNU Emacs is written in the Emacs Lisp extension language, one only needs to port the C core which implements the Emacs Lisp interpreter. This makes porting Emacs to a new platform considerably less difficult than porting an equivalent project consisting of native code only. GNU Emacs development was relatively closed until 1999 and

1794-462: Is launched with no file to edit. The tutorial is by Stuart Cracraft and Richard Stallman. The Church of Emacs , formed by Richard Stallman , is a parody religion created for Emacs users. While it refers to vi as the editor of the beast (vi-vi-vi being 6-6-6 in Roman numerals), it does not oppose the use of vi; rather, it calls it proprietary software anathema . ("Using a free version of vi

1872-542: Is not a sin but a penance .") The Church of Emacs has its own newsgroup , alt.religion.emacs , that has posts purporting to support this parody religion. Supporters of vi have created an opposing Cult of vi . Stallman has jokingly referred to himself as St I  GNU  cius , a saint in the Church of Emacs. This is in reference to Ignatius of Antioch , an early Church father venerated in Christianity. The word emacs

1950-449: Is required, simply by declaring the client program to be the user's EDITOR or VISUAL variable. Such a server continues to run in the background, managing any child processes, accumulating stdin from open pipes, ports, or fifos, performing periodic or pre-programmed actions, and remembering buffer undo history, saved text snippets, command history, and other user state between editing sessions. In this mode of operation, Emacs overlaps

2028-408: Is sometimes pluralized as emacsen , by phonetic analogy with boxen and VAXen , referring to different varieties of Emacs. User interface In the industrial design field of human–computer interaction , a user interface ( UI ) is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine from

2106-457: Is supplied, the universal argument is 1 : every command implicitly runs once, but may be called multiply, or in a different way, when supplied with such a prefix. Such arguments may also be non-positive where it makes sense for them to be so - it is up to the function accepting the argument to determine, according to its own semantics, what a given number means to it. One common usage is for functions to perform actions in reverse simply by checking

2184-449: Is the number of senses interfaced with. For example, a Smell-O-Vision is a 3-sense (3S) Standard CUI with visual display, sound and smells; when virtual reality interfaces interface with smells and touch it is said to be a 4-sense (4S) virtual reality interface; and when augmented reality interfaces interface with smells and touch it is said to be a 4-sense (4S) augmented reality interface. The user interface or human–machine interface

2262-502: Is the part of the machine that handles the human–machine interaction. Membrane switches, rubber keypads and touchscreens are examples of the physical part of the Human Machine Interface which we can see and touch. In complex systems, the human–machine interface is typically computerized. The term human–computer interface refers to this kind of system. In the context of computing, the term typically extends as well to

2340-489: The C programming language , which enables GNU Emacs to be ported to a wide variety of operating systems and architectures without modifying the implementation semantics of the Lisp system where most of the editor lives. In this Lisp environment, variables and functions can be modified with no need to rebuild or restart Emacs, with even newly redefined versions of core editor features being asynchronously compiled and loaded into

2418-460: The Lisp machine by Mike McMahon and Daniel Weinreb , and Sine ( Sine Is Not Eine ), which was written by Owen Theodore Anderson. Weinreb's EINE was the first Emacs written in Lisp. In 1978, Bernard Greenberg wrote Multics Emacs almost entirely in Multics Lisp at Honeywell 's Cambridge Information Systems Lab. Multics Emacs was later maintained by Richard Soley , who went on to develop

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2496-562: The TENEX and TOPS-20 operating systems. Other contributors to early versions of Emacs include Kent Pitman , Earl Killian , and Eugene Ciccarelli . By 1979, Emacs was the main editor used in MIT's AI lab and its Laboratory for Computer Science. In the following years, programmers wrote a variety of Emacs-like editors for other computer systems. These included EINE ( EINE Is Not EMACS ) and ZWEI ( ZWEI Was EINE Initially ), which were written for

2574-426: The sign of the universal argument, such as a sort command which sorts in obverse by default and in reverse when called with a negative argument, using the absolute value of its argument as the sorting key (e.g. -7 sorting in reverse by column index (or delimiter) 7), or undo/redo, which are simply negatives of each other (traversing forward and backward through a recursive history of diffs by some number of steps at

2652-576: The AI Lab and soon accumulated a large collection of custom macros whose names often ended in MAC or MACS , which stood for macro . Two years later, Guy Steele took on the project of unifying the diverse macros into a single set. Steele and Stallman's finished implementation included facilities for extending and documenting the new macro set. The resulting system was called EMACS, which stood for Editing MACroS or, alternatively, E with MACroS . Stallman picked

2730-854: The NILE Emacs-like editor for the NIL Project, and by Barry Margolin. Many versions of Emacs, including GNU Emacs, would later adopt Lisp as an extension language. James Gosling , who would later invent NeWS and the Java programming language , wrote Gosling Emacs in 1981. The first Emacs-like editor to run on Unix , Gosling Emacs was written in C and used Mocklisp , a language with Lisp-like syntax, as an extension language. Early Ads for Computer Corporation of America 's CCA EMACS (Steve Zimmerman) appeared in 1984. 1985 comparisons to GNU Emacs, when it came out, mentioned free vs. $ 2,400. Richard Stallman began work on GNU Emacs in 1984 to produce

2808-561: The best-known early forks in free software development occurred when the codebases of the two Emacs versions diverged and the separate development teams ceased efforts to merge them back into a single program. Lucid Emacs has since been renamed XEmacs . Its development is currently inactive, with the most recent stable version 21.4.22 released in January 2009 (while a beta was released in 2013), while GNU Emacs has implemented many formerly XEmacs-only features. Other notable forks include: In

2886-464: The body is required, and sensors noting the position of the head, direction of gaze and so on have been used experimentally. This is particularly relevant to immersive interfaces . The history of user interfaces can be divided into the following phases according to the dominant type of user interface: In the batch era, computing power was extremely scarce and expensive. User interfaces were rudimentary. Users had to accommodate computers rather than

2964-402: The computer pioneers of the 1940s. Just as importantly, the existence of an accessible screen—a two-dimensional display of text that could be rapidly and reversibly modified—made it economical for software designers to deploy interfaces that could be described as visual rather than textual. The pioneering applications of this kind were computer games and text editors; close descendants of some of

3042-423: The currently running job the entire computer; program decks and tapes had to include what we would now think of as operating system code to talk to I/O devices and do whatever other housekeeping was needed. Midway through the batch period, after 1957, various groups began to experiment with so-called " load-and-go " systems. These used a monitor program which was always resident on the computer. Programs could call

3120-480: The data that Emacs users interact with, are displayed to the user inside windows , which are tiled portions of the terminal screen or the GUI window, which Emacs refers to as frames ; in modern terminology, an Emacs frame would be a window and an Emacs window would be a split. Depending on configuration, windows can include their own scroll bars, line numbers, sometimes a 'header line' typically to ease navigation, and

3198-523: The designer is experienced with other interfaces, they will similarly develop habits, and often make unconscious assumptions regarding how the user will interact with the interface. Peter Morville of Google designed the User Experience Honeycomb framework in 2004 when leading operations in user interface design. The framework was created to guide user interface design. It would act as a guideline for many web development students for

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3276-615: The earliest specimens, such as rogue (6), and vi (1), are still a live part of Unix tradition. In 1985, with the beginning of Microsoft Windows and other graphical user interfaces , IBM created what is called the Systems Application Architecture (SAA) standard which include the Common User Access (CUA) derivative. CUA successfully created what we know and use today in Windows, and most of

3354-401: The expression graphical user interface for human–machine interface on computers, as nearly all of them are now using graphics. Multimodal interfaces allow users to interact using more than one modality of user input. There is a difference between a user interface and an operator interface or a human–machine interface (HMI). In science fiction , HMI is sometimes used to refer to what

3432-399: The features of text terminal frames. The first Emacs contained a help library that included documentation for every command, variable and internal function. Because of this, Emacs proponents described the software as self-documenting in that it presents the user with information on its normal features and its current state. Each function includes a documentation string that is displayed to

3510-430: The first public release, was made on March 20, 1985. The first widely distributed version of GNU Emacs was version 15.34, released later in 1985. Early versions of GNU Emacs were numbered as 1.x.x , with the initial digit denoting the version of the C core. The 1 was dropped after version 1.12, as it was thought that the major number would never change, and thus the numbering skipped from 1 to 13 . In September 2014, it

3588-483: The functionality in Emacs, including basic editing operations such as the insertion of characters into a file, is achieved through functions written in a dialect of the Lisp programming language . The dialect used in GNU Emacs is known as Emacs Lisp (Elisp), and was developed expressly to port Emacs to GNU and Unix . The Emacs Lisp layer sits atop a stable core of basic services and platform abstraction written in

3666-406: The functionality of programs like screen and tmux . Because of its separation of display concerns from editing functionality, Emacs can display roughly similarly on any device more complex than a dumb terminal , including providing typical graphical WIMP elements on sufficiently featureful text terminals - though graphical frames are the preferred mode of display, providing a strict superset of

3744-453: The goal of user interface design is to produce a user interface that makes it easy, efficient, and enjoyable (user-friendly) to operate a machine in the way which produces the desired result (i.e. maximum usability ). This generally means that the operator needs to provide minimal input to achieve the desired output, and also that the machine minimizes undesired outputs to the user. User interfaces are composed of one or more layers, including

3822-470: The human end, while the machine simultaneously feeds back information that aids the operators' decision-making process. Examples of this broad concept of user interfaces include the interactive aspects of computer operating systems , hand tools , heavy machinery operator controls and process controls. The design considerations applicable when creating user interfaces are related to, or involve such disciplines as, ergonomics and psychology . Generally,

3900-422: The interface and features of the editor and to encode its user-defined configuration and options. The goal of Emacs' open design is to transparently expose Emacs' internals to the Emacs user during normal use in the same way that they would be exposed to the Emacs developer working on the git tree , and to collapse as much as possible of the distinction between using Emacs and programming Emacs, while still providing

3978-482: The interface design include prototyping and simulation. Typical human–machine interface design consists of the following stages: interaction specification, interface software specification and prototyping: In broad terms, interfaces generally regarded as user friendly, efficient, intuitive, etc. are typified by one or more particular qualities. For the purpose of example, a non-exhaustive list of such characteristics follows: The principle of least astonishment (POLA)

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4056-728: The key used to call it. For example, pressing the f key in a buffer that accepts text input evaluates the code ( self-insert-command 1 ?f ) , which inserts one copy of the character constant ?f at point . The 1 , in this case, is determined by what Emacs terms the universal argument : all Emacs command code accepts a numeric value which, in its simplest usage, indicates repetition of an action, but in more complex cases (where repetition doesn't make sense) can yield other behaviours. These arguments may be supplied via command prefices, such as Control + u 7 f , or more compactly Meta + 7 f , which expands to ( self-insert-command 7 ?f ) . When no prefix

4134-404: The lab's E editor, written by Fred Wright. He was impressed by the editor's intuitive WYSIWYG (What You See Is What You Get) behavior, which has since become the default behavior of most modern text editors. He returned to MIT where Carl Mikkelsen, a hacker at the AI Lab, had added to TECO a combined display/editing mode called Control-R that allowed the screen display to be updated each time

4212-448: The live environment to replace existing definitions. Modern GNU Emacs features both bytecode and native code compilation for Emacs Lisp. All configuration is stored in variables, classes, and data structures, and changed by simply updating these live. The use of a Lisp dialect in this case is a key advantage, as Lisp syntax consists of so-called symbolic expressions (or sexprs), which can act as both evaluatable code expressions and as

4290-639: The machine use no input or output devices except electrodes alone; they are called brain–computer interfaces (BCIs) or brain–machine interfaces (BMIs). Other terms for human–machine interfaces are man–machine interface ( MMI ) and, when the machine in question is a computer, human–computer interface . Additional UI layers may interact with one or more human senses, including: tactile UI ( touch ), visual UI ( sight ), auditory UI ( sound ), olfactory UI ( smell ), equilibria UI ( balance ), and gustatory UI ( taste ). Composite user interfaces ( CUIs ) are UIs that interact with two or more senses. The most common CUI

4368-441: The monitor for services. Another function of the monitor was to do better error checking on submitted jobs, catching errors earlier and more intelligently and generating more useful feedback to the users. Thus, monitors represented the first step towards both operating systems and explicitly designed user interfaces. Command-line interfaces ( CLIs ) evolved from batch monitors connected to the system console. Their interaction model

4446-545: The more recent DOS or Windows Console Applications will use that standard as well. This defined that a pulldown menu system should be at the top of the screen, status bar at the bottom, shortcut keys should stay the same for all common functionality (F2 to Open for example would work in all applications that followed the SAA standard). This greatly helped the speed at which users could learn an application so it caught on quick and became an industry standard. Primary methods used in

4524-606: The most part, compatible with each other. XEmacs development is inactive. GNU Emacs is, along with vi , one of the two main contenders in the traditional editor wars of Unix culture. GNU Emacs is among the oldest free and open source projects still under development. Emacs development began during the 1970s at the MIT AI Lab , whose PDP-6 and PDP-10 computers used the Incompatible Timesharing System (ITS) operating system that featured

4602-411: The name Emacs "because <E> was not in use as an abbreviation on ITS at the time." An apocryphal hacker koan alleges that the program was named after Emack & Bolio's , a popular Boston ice cream store. The first operational EMACS system existed in late 1976. Stallman saw a problem in too much customization and de facto forking and set certain conditions for usage. He later wrote: EMACS

4680-497: The other way around; user interfaces were considered overhead, and software was designed to keep the processor at maximum utilization with as little overhead as possible. The input side of the user interfaces for batch machines was mainly punched cards or equivalent media like paper tape . The output side added line printers to these media. With the limited exception of the system operator's console , human beings did not interact with batch machines in real time at all. Submitting

4758-632: The past, projects aimed at producing small versions of Emacs proliferated. GNU Emacs was initially targeted at computers with a 32-bit flat address space and at least 1  MiB of RAM. Such computers were high end workstations and minicomputers in the 1980s, and this left a need for smaller reimplementations that would run on common personal computer hardware. Today's computers have more than enough power and capacity to eliminate these restrictions, but small clones have more recently been designed to fit on software installation disks or for use on less capable hardware. Other projects aim to implement Emacs in

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4836-521: The real world to create a virtual reality , the CUI is virtual and uses a virtual reality interface . When the CUI does not block out the real world and creates augmented reality , the CUI is augmented and uses an augmented reality interface . When a UI interacts with all human senses, it is called a qualia interface, named after the theory of qualia . CUI may also be classified by how many senses they interact with as either an X-sense virtual reality interface or X-sense augmented reality interface, where X

4914-490: The required characters, during which time the edited text was not displayed on the screen, and finally enter a character (<esc>) to switch the editor back to command mode. (A similar technique was used to allow overtyping.) This behavior is similar to that of the program ed . By the 1970s, TECO was already an old program, initially released in 1962. Richard Stallman visited the Stanford AI Lab in 1976 and saw

4992-641: The respective prefices: C- , A- , S- , M- , s- , and H- . Keys whose names are only printable with more than one character are enclosed in angle brackets. Thus, a keyboard shortcut such as Ctrl + Alt + ⇧ Shift + F9 (check dependent formulas and calculate all cells in all open workbooks in Excel ) would be rendered in Emacs command language as C-A-S-<f9> , while an Emacs command like Meta + s f Ctrl + Meta + s (incremental file search by filename-matching regexp ), would be expressed as M-s f C-M-s . Command language

5070-404: The role at times. Stefan Monnier and Chong Yidong were maintainers from 2008 to 2015. John Wiegley was named maintainer in 2015 after a meeting with Stallman at MIT. As of early 2014, GNU Emacs has had 579 individual committers throughout its history. Lucid Emacs, based on an early alpha version of GNU Emacs 19, was developed beginning in 1991 by Jamie Zawinski and others at Lucid Inc. One of

5148-416: The same buffer, for example to track different parts of a long text side-by-side without scrolling back and forth, and multiple buffers can share the same text, for example to take advantage of different major modes in a mixed-language file. Similarly, Emacs instances are not associated with particular frames, and multiple frames can be opened displaying a single running Emacs process, e.g. a frame per screen in

5226-447: The second phase of command-line systems. These cut latency further, because characters could be thrown on the phosphor dots of a screen more quickly than a printer head or carriage can move. They helped quell conservative resistance to interactive programming by cutting ink and paper consumables out of the cost picture, and were to the first TV generation of the late 1950s and 60s even more iconic and comfortable than teleprinters had been to

5304-404: The smallest possible compilers and interpreters. Once the cards were punched, one would drop them in a job queue and wait. Eventually, operators would feed the deck to the computer, perhaps mounting magnetic tapes to supply another dataset or helper software. The job would generate a printout, containing final results or an abort notice with an attached error log. Successful runs might also write

5382-557: The software dedicated to control the physical elements used for human–computer interaction . The engineering of human–machine interfaces is enhanced by considering ergonomics ( human factors ). The corresponding disciplines are human factors engineering (HFE) and usability engineering (UE) which is part of systems engineering . Tools used for incorporating human factors in the interface design are developed based on knowledge of computer science , such as computer graphics , operating systems , programming languages . Nowadays, we use

5460-457: The user entered a keystroke. Stallman reimplemented this mode to run efficiently and then added a macro feature to the TECO display-editing mode that allowed the user to redefine any keystroke to run a TECO program. E had another feature that TECO lacked: random-access editing. TECO was a page-sequential editor that was designed for editing paper tape on the PDP-1 at a time when computer memory

5538-428: The user in various ways (e.g. a family of eval- functions, operating on the buffer , region , or individual expression ). Even the simplest user inputs (such a printable characters ) are effectuated as Emacs Lisp functions, such as the self-insert-command , bound by default to most keyboard keys in a typical text editing buffer, which parameterises itself with the locale -defined character associated with

5616-405: The user on request, a practice that subsequently spread to programming languages including Lisp , Java , Perl , and Python . This help system can take users to the actual code for each function, whether from a built-in library or an added third-party library. Emacs also has a built-in tutorial . Emacs displays instructions for performing simple editing commands and invoking the tutorial when it

5694-496: Was a series of request-response transactions, with requests expressed as textual commands in a specialized vocabulary. Latency was far lower than for batch systems, dropping from days or hours to seconds. Accordingly, command-line systems allowed the user to change their mind about later stages of the transaction in response to real-time or near-real-time feedback on earlier results. Software could be exploratory and interactive in ways not possible before. But these interfaces still placed

5772-589: Was announced on the GNU emacs-devel mailing list that GNU Emacs would adopt a rapid release strategy and version numbers would increment more quickly in the future. GNU Emacs offered more features than Gosling Emacs, in particular a full-featured Lisp as its extension language, and soon replaced Gosling Emacs as the de facto Unix Emacs editor. Markus Hess exploited a security flaw in GNU Emacs' email subsystem in his 1986 cracking spree in which he gained superuser access to Unix computers. Most of GNU Emacs functionality

5850-475: Was distributed on a basis of communal sharing, which means all improvements must be given back to me to be incorporated and distributed. The original Emacs, like TECO, ran only on the PDP-10 running ITS. Its behavior was sufficiently different from that of TECO that it could be considered a text editor in its own right, and it quickly became the standard editing program on ITS. Mike McMahon ported Emacs from ITS to

5928-511: Was generally small due to cost, and it was a feature of TECO that allowed editing on only one page at a time sequentially in the order of the pages in the file. Instead of adopting E's approach of structuring the file for page-random access on disk, Stallman modified TECO to handle large buffers more efficiently and changed its file-management method to read, edit, and write the entire file as a single buffer. Almost all modern editors use this approach. The new version of TECO quickly became popular at

6006-672: Was used as an example of the Cathedral development style in The Cathedral and the Bazaar . The project has since adopted a public development mailing list and anonymous CVS access. Development took place in a single CVS trunk until 2008 and was then switched to the Bazaar DVCS . On November 11, 2014, development was moved to Git . Richard Stallman has remained the principal maintainer of GNU Emacs, but he has stepped back from

6084-598: Was written in 1976 by David A. Moon and Guy L. Steele Jr. as a set of macros for the TECO editor. It was inspired by the ideas of the TECO-macro editors TECMAC and TMACS. The most popular, and most ported, version of Emacs is GNU Emacs, which was created by Richard Stallman for the GNU Project . XEmacs is a variant that branched from GNU Emacs in 1991. GNU Emacs and XEmacs use similar Lisp dialects and are, for

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