Liblouis User's and Programmer's Manual
This manual is for liblouis (version 3.33.0, 3 March 2025), a Braille Translation and Back-Translation Library derived from the Linux screen reader BRLTTY.
Copyright © 1999-2006 by the BRLTTY Team.
Copyright © 2004-2007 ViewPlus Technologies, Inc. www.viewplus.com.
Copyright © 2007, 2009 Abilitiessoft, Inc. www.abilitiessoft.org.
Copyright © 2014, 2016 Swiss Library for the Blind, Visually Impaired and Print Disabled. www.sbs.ch.
This file is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser (or library) General Public License (LGPL) as published by the Free Software Foundation; either version 3, or (at your option) any later version.
This file is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser (or Library) General Public License LGPL for more details.
You should have received a copy of the GNU Lesser (or Library) General Public License (LGPL) along with this program; see the file COPYING. If not, write to the Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
Table of Contents
- 1 Introduction
- 2 How to Write Translation Tables
- 2.1 Overview
- 2.2 Hyphenation Tables
- 2.3 Character-Definition Opcodes
- 2.4 Braille Indicator Opcodes
- 2.5 Opcodes for Standing Alone Sequences
- 2.6 Emphasis Opcodes
- 2.7 Special Symbol Opcodes
- 2.8 Special Processing Opcodes
- 2.9 Translation Opcodes
- 2.10 Character-Class Opcodes
- 2.11 Swap Opcodes
- 2.12 The Context and Multipass Opcodes
- 2.13 The correct Opcode
- 2.14 The match Opcode
- 2.15 Miscellaneous Opcodes
- 3 Notes on Back-Translation
- 4 Table Metadata
- 5 Testing Translation Tables interactively
- 6 Automated Testing of Translation Tables
- 7 Programming with liblouis
- 7.1 Overview
- 7.2 Data structure of liblouis tables
- 7.3 How tables are found
- 7.4 Deprecation of the logging system
- 7.5 lou_version
- 7.6 lou_translateString
- 7.7 lou_translate
- 7.8 lou_backTranslateString
- 7.9 lou_backTranslate
- 7.10 lou_hyphenate
- 7.11 lou_compileString
- 7.12 lou_getTypeformForEmphClass
- 7.13 lou_dotsToChar
- 7.14 lou_charToDots
- 7.15 lou_registerLogCallback
- 7.16 lou_setLogLevel
- 7.17 lou_logFile (deprecated)
- 7.18 lou_logPrint (deprecated)
- 7.19 lou_logEnd (deprecated)
- 7.20 lou_setDataPath
- 7.21 lou_getDataPath
- 7.22 lou_getTable
- 7.23 lou_findTable
- 7.24 lou_indexTables
- 7.25 lou_checkTable
- 7.26 lou_readCharFromFile
- 7.27 lou_free
- 7.28 lou_charSize
- 7.29 Python bindings
- Concept Index
- Opcode Index
- Function Index
- Program Index