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 operating systems.
Appearing in Version 6 Unix,
was originally written by Stephen C. Johnson of Bell Labs in 1975. Douglas McIlroy 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: 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 systems, such as aspell, MySpell and hunspell, 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 version of McIlroy's has never been written. Instead, in 1996 Thomas Morgan of GNU wrote a simple wrapper to (which was already popular at the time) to replicate spell's original behaviour. Many Linux distributions include this GNU , or an even simpler shell script; For example, the "" command in Fedora Linux simply runs , as:
cat "$@" , aspell -l --mode=none , sort -u
See also
*ispell
*aspell
*MySpell
*pspell
*hunspell
References
External links
Original Unix spell source code(link does not work)
*
{{Plan 9 commands
1975 software
Standard Unix programs
Plan 9 commands