is the standard

English language English is a West Germanic language of the Indo-European language family, with its earliest forms spoken by the inhabitants of early medieval England. It is named after the Angles, one of the ancient Germanic peoples that migrated to the is ...

spell checker In software, a spell checker (or spelling checker or spell check) is a software feature that checks for misspellings in a text. Spell-checking features are often embedded in software or services, such as a word processor, email client, electronic di ...

for

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser 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 ot ...

, Plan 9, and

Unix-like A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

s. Appearing in

Version 6 Unix Sixth Edition Unix, also called Version 6 Unix or just V6, was the first version of the Unix operating system to see wide release outside Bell Labs. It was released in May 1975 and, like its direct predecessor, targeted the DEC PDP-11 family of m ...

, was originally written by

Stephen C. Johnson Stephen Curtis Johnson (b. 1944; known as Steve Johnson) is a computer scientist who worked at Bell Labs and Old AT&T, AT&T for nearly 20 years. He is best known for Yacc, Lint (software), Lint, spell (Unix), spell, and the Portable C Compiler, w ...

Bell Labs Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by mult ...

in 1975.

Douglas McIlroy Malcolm Douglas McIlroy (born 1932) is a mathematician, engineer, and programmer. As of 2019 he is an Adjunct Professor of Computer Science at Dartmouth College. McIlroy is best known for having originally proposed Unix pipelines and developed se ...

later improved its accuracy, performance, and memory use, and described his work and ''spell'' in general in his 1982 paper
Development of a Spelling list
. Spell has a simple

command-line interface A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and pro ...

: It goes over all the words in a given text file, and prints a sorted list of unique misspelled words in that file. It does not provide any interface for looking for those words in the file, or helping to correct the mistakes. In 1983, a different spell-checker, (the ''interactive'' spell-checker), was ported to Unix. had a user interface for showing the spelling mistakes in context and suggesting how to correct them. Since then, the original Spell tool has been mostly considered obsolete. Another reason Spell is considered obsolete is that it only supports the English language. Modern spell-checkers for Unix and

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...

systems, such as

aspell GNU Aspell, usually called just Aspell, is a free software spell checker designed to replace Ispell. It is the standard spell checker for the GNU operating system. It also compiles for other Unix-like operating systems and Windows. The main pro ...

MySpell MySpell is a spell checker that was formerly included with OOo Writer of the free OpenOffice.org office suite. Since version 2.0.2, OpenOffice.org has replaced MySpell with Hunspell. Background MySpell was started by Kevin Hendricks in an att ...

and

hunspell Hunspell is a spell checker and morphological analyser designed for languages with rich morphology and complex word compounding and character encoding, originally designed for the Hungarian language. Hunspell is based on MySpell and is backwar ...

, support a multitude of different languages and character sets. The Single Unix Specification has officially declared Spell a "legacy application", stating that this was done "because there is no known technology that can be used to make it recognise general language for user-specified input without providing a complete dictionary along with the input file." Nevertheless, the Single Unix Specification does not standardize any other spell-checking utility to take Spell's place. Because of Spell's problems and the superiority of its alternatives, a

free software Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, no ...

version of McIlroy's has never been written. Instead, in 1996 Thomas Morgan of

GNU GNU () is an extensive collection of free software (383 packages as of January 2022), which can be used as an operating system or can be used in parts with other operating systems. The use of the completed GNU tools led to the family of operat ...

wrote a simple wrapper to (which was already popular at the time) to replicate spell's original behaviour. Many

Linux distributions A Linux distribution (often abbreviated as distro) is an operating system made from a software collection that includes the Linux kernel and, often, a package management system. Linux users usually obtain their operating system by downloading one ...

include this GNU , or an even simpler

shell script A shell script is a computer program designed to be run by a Unix shell, a command-line interpreter. The various dialects of shell scripts are considered to be scripting languages. Typical operations performed by shell scripts include file manip ...

; For example, the "" command in

Fedora Linux Fedora Linux is a Linux distribution developed by the Fedora Project. Fedora contains software distributed under various free and open-source licenses and aims to be on the leading edge of open-source technologies. Fedora is the upstream sourc ...

simply runs , as: cat "$@" , aspell -l --mode=none , sort -u

References

External links

Original Unix spell source code
(link does not work) * {{Plan 9 commands 1975 software Standard Unix programs Plan 9 commands

See also

References

External links