getting arguments computed by a swi program from a bash shell

Hello,

(I am using swi-prolog 64 bits 6.5.1 under ubuntu 12.04)

I call a swi-prolog program from a bash shell.
This program computes values that I would like to
get from the shell.
How can I do this ?
(presently I use a file to write, but I think there is
  a simpler way).

Thanks a lot for your answers.

Dominique.