Where is the pg_terminate_backend() function? Way to execute shell cmd

[Uyelik <uyelik@xxxxxxxxxxxxxxxxx>]

Hi,
1. On Postgresql 8.1.4, i can't use pg_terminate_backend(int) function. How can i use this function?
2. How can i execute a shell command?
I need to terminate a client connection(some times active, some times idle one) by a query. I can undertake the risc for it. :)

Regards,
Mustafa Yorukoglu