Hi,
> Could someone help me how to use the langmap configuration variable?
> I tried to search in GNU Global manual but it does not show how to
> write and use a configuration file for GNU Global.
Being written in gtags(1) is all about it.
Gtags's langmap variable has the almost same role as ctags's langmap option.
Typing 'man ctags' will be help for you.
Shigio