Hunspell is a free spell checker and morphological analyzer library and command-line tool, licensed under LGPL/GPL/MPL tri-license.
Hunspell is used by LibreOffice office suite, free browsers, like Mozilla Firefox and Google Chrome, and other tools and OSes, like Linux distributions and macOS. It is also a command-line tool for Linux, Unix-like and other OSes.
It is designed for quick and high quality spell checking and correcting for languages with word-level writing system, including languages with rich morphology, complex word compounding and character encoding.
Hunspell interfaces: Ispell-like terminal interface using Curses library, Ispell pipe interface, C++/C APIs and shared library, also with existing language bindings for other programming languages.
Hunspell's code base comes from OpenOffice.org's MySpell library, developed by Kevin Hendricks (originally a C++ reimplementation of spell checking and affixation of Geoff Kuenning's International Ispell from scratch, later extended with eg. n-gram suggestions), see http://lingucomponent.openoffice.org/MySpell-3.zip, and its README, CONTRIBUTORS and license.readme (here: license.myspell) files.
Main features of Hunspell library, developed by László Németh:
- Unicode support
- Highly customizable suggestions: word-part replacement tables and stem-level phonetic and other alternative transcriptions to recognize and fix all typical misspellings, don't suggest offensive words etc.
- Complex morphology: dictionary and affix homonyms; twofold affix stripping to handle inflectional and derivational morpheme groups for agglutinative languages, like Azeri, Basque, Estonian, Finnish, Hungarian, Turkish; 64 thousand affix classes with arbitrary number of affixes; conditional affixes, circumfixes, fogemorphemes, zero morphemes, virtual dictionary stems, forbidden words to avoid overgeneration etc.
- Handling complex compounds (for example, for Finno-Ugric, German and Indo-Aryan languages): recognizing compounds made of arbitrary number of words, handle affixation within compounds etc.
- Custom dictionaries with affixation
- Stemming
- Morphological analysis (in custom item and arrangement style)
- Morphological generation
- SPELLML XML API over plain spell() API function for easier integration of stemming, morpological generation and custom dictionaries with affixation
- Language specific algorithms, like special casing of Azeri or Turkish dotted i and German sharp s, and special compound rules of Hungarian.
Main features of Hunspell command line tool, developed by László Németh:
- Reimplementation of quick interactive interface of Geoff Kuenning's Ispell
- Parsing formats: text, OpenDocument, TeX/LaTeX, HTML/SGML/XML, nroff/troff
- Custom dictionaries with optional affixation, specified by a model word
- Multiple dictionary usage (for example hunspell -d en_US,de_DE,de_medical)
- Various filtering options (bad or good words/lines)
- Morphological analysis (option -m)
- Stemming (option -s)
See man hunspell, man 3 hunspell, man 5 hunspell for complete manual.
Build only dependencies:
g++ make autoconf automake autopoint libtool
Runtime dependencies:
| Mandatory | Optional | |
|---|---|---|
| libhunspell | ||
| hunspell tool | libiconv gettext | ncurses readline |
We first need to download the dependencies. On Linux, gettext and
libiconv are part of the standard library. On other Unixes we
need to manually install them.
For Ubuntu:
sudo apt install autoconf automake autopoint libtool
Then run the following commands:
autoreconf -vfi
./configure
make
sudo make install
sudo ldconfig
For dictionary development, use the --with-warnings option of
configure.
For interactive user interface of Hunspell executable, use the
--with-ui option.
Optional developer packages:
- ncurses (need for --with-ui), eg. libncursesw5 for UTF-8
- readline (for fancy input line editing, configure parameter: --with-readline)
In Ubuntu, the packages are:
libncurses5-dev libreadline-dev
On macOS for compiler always use clang and not g++ because Homebrew
dependencies are build with that.
brew install autoconf automake libtool gettext
brew link gettext --force
Then run autoreconf, configure, make. See above.
Download Msys2, update everything and install the following packages:
pacman -S base-devel mingw-w64-x86_64-toolchain mingw-w64-x86_64-libtool
Open Mingw-w64 Win64 prompt and compile the same way as on Linux, see above.
Download and install Cygwin environment for Windows with the following extra packages:
- make
- automake
- autoconf
- libtool
- gcc-g++ development package
- ncurses, readline (for user interface)
- iconv (character conversion)
Then compile the same way as on Linux. Cygwin builds depend on Cygwin1.dll.
It is recommended to install a debug build of the standard library:
libstdc++6-6-dbg
For debugging we need to create a debug build and then we need to start
gdb.
./configure CXXFLAGS='-g -O0 -Wall -Wextra'
make
./libtool --mode=execute gdb src/tools/hunspell
You can also pass the CXXFLAGS directly to make without calling
./configure, but we don't recommend this way during long development
sessions.
If you like to develop and debug with an IDE, see documentation at https://github.com/hunspell/hunspell/wiki/IDE-Setup
Testing Hunspell (see tests in tests/ subdirectory):
make check
or with Valgrind debugger:
make check
VALGRIND=[Valgrind_tool] make check
For example:
make check
VALGRIND=memcheck make check
features and dictionary format:
man 5 hunspell
man hunspell
hunspell -h
After compiling and installing (see INSTALL) you can run the Hunspell spell checker (compiled with user interface) with a Hunspell or Myspell dictionary:
hunspell -d en_US text.txt
or without interface:
hunspell
hunspell -d en_GB -l <text.txt
Dictionaries consist of an affix (.aff) and dictionary (.dic) file, for example, download American English dictionary files of LibreOffice (older version, but with stemming and morphological generation) with
wget -O en_US.aff https://cgit.freedesktop.org/libreoffice/dictionaries/plain/en/en_US.aff?id=a4473e06b56bfe35187e302754f6baaa8d75e54f
wget -O en_US.dic https://cgit.freedesktop.org/libreoffice/dictionaries/plain/en/en_US.dic?id=a4473e06b56bfe35187e302754f6baaa8d75e54f
and with command line input and output, it's possible to check its work quickly, for example with the input words "example", "examples", "teached" and "verybaaaaaaaaaaaaaaaaaaaaaad":
$ hunspell -d en_US
Hunspell 1.7.0
example
*
examples
+ example
teached
& teached 9 0: taught, teased, reached, teaches, teacher, leached, beached
verybaaaaaaaaaaaaaaaaaaaaaad
# verybaaaaaaaaaaaaaaaaaaaaaad 0
Where in the output, * and + mean correct (accepted) words (* = dictionary stem,
+ = affixed forms of the following dictionary stem), and
& and # mean bad (rejected) words (& = with suggestions, # = without suggestions)
(see man hunspell).
Example for stemming:
$ hunspell -d en_US -s
mice
mice mouse
Example for morphological analysis (very limited with this English dictionary):
$ hunspell -d en_US -m
mice
mice st:mouse ts:Ns
cats
cats st:cat ts:0 is:Ns
cats st:cat ts:0 is:Vs
The src/tools directory contains the following executables after compiling.
- The main executable:
- hunspell: main program for spell checking and others (see manual)
- Example tools:
- analyze: example of spell checking, stemming and morphological analysis
- chmorph: example of automatic morphological generation and conversion
- example: example of spell checking and suggestion
- Tools for dictionary development:
- affixcompress: dictionary generation from large (millions of words) vocabularies
- makealias: alias compression (Hunspell only, not back compatible with MySpell)
- wordforms: word generation (Hunspell version of unmunch)
- hunzip: decompressor of hzip format
- hzip: compressor of hzip format
- munch (DEPRECATED, use affixcompress): dictionary generation from vocabularies (it needs an affix file, too).
- unmunch (DEPRECATED, use wordforms): list all recognized words of a MySpell dictionary
Example for morphological generation:
$ ~/hunspell/src/tools/analyze en_US.aff en_US.dic /dev/stdin
cat mice
generate(cat, mice) = cats
mouse cats
generate(mouse, cats) = mice
generate(mouse, cats) = mouses
Including in your program:
#include <hunspell.hxx>
Linking with Hunspell static library:
g++ -lhunspell-1.7 example.cxx
# or better, use pkg-config
g++ $(pkg-config --cflags --libs hunspell) example.cxx
Hunspell (MySpell) dictionaries:
- https://wiki.documentfoundation.org/Language_support_of_LibreOffice
- http://cgit.freedesktop.org/libreoffice/dictionaries
- http://extensions.libreoffice.org
- http://extensions.openoffice.org
- http://wiki.services.openoffice.org/wiki/Dictionaries
Aspell dictionaries (conversion: man 5 hunspell):
- ftp://ftp.gnu.org/gnu/aspell/dict
László Németh, nemeth at numbertext org