Using CLI - language
Language is set at compile time
Language is set at compile time and is based on the LANG environment variable value - so it should automatically cater for your language.
Supported languages : English and French
Currently only French and English are supported.
If you want to change compile-time language, you should compile using (example for US and UTF-8 locale) :
# make LANG=en_US.UTF8
if you want English from a French-locale system, or conversely :
# make LANG=fr_FR.UTF8
if you want French from a non-French system. This impacts only messages and keyboard layout display to the user, not the core program.
Warning for graphical interface : as GTK uses standard buttons known as "stock", in order for those to also display in another language, it is necessary that your implementation of GTK takes them into account.