switching keyboards

["linux user" <sudebian gmail com>]

Dear Colleagues,

I'd like to know:

1)the way (a system call, maybe, in a programming language C) to get
the name (the reference) of different keyboard maps (i.e., layouts)
defined -I think- in the X11 linux system, and

2)a system call -maybe- to change the keyboard according each of those
"references".

Anybody could help me ?