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LOU_TRACE(1) User Commands LOU_TRACE(1)


lou_trace - A tool to list all the rules that were used for a Braille translation


lou_trace [OPTIONS] TABLE[,TABLE,...]


Examine and debug Braille translation tables. This program allows you to inspect liblouis translation tables by printing out the list of applied translation rules for a given input.

display this help and exit
display version information and exit
forward translation using the given table
backward translation using the given table
Use no contractions
Display dot patterns
Use Unicode Braille patterns
Disable output of undefined dot numbers during back-translation
Use partial back-translation If neither -f nor -b are specified forward translation is assumed


Written by Bert Frees.


Report bugs to
Liblouis home page: <>


Copyright © 2022 Swiss Library for the Blind, Visually Impaired and Print Disabled. License GPLv3+: GNU GPL version 3 or later <>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.


The full documentation for lou_trace is maintained as a Texinfo manual. If the info and lou_trace programs are properly installed at your site, the command

info liblouis

should give you access to the complete manual.

September 2022 Liblouis 3.23.0