How call a C program when the user log-in??

Marcos Lima (marcos@unitnet.com.br)
Mon, 7 Apr 1997 11:29:09 -0300 (EST)

Hi all,

I would like know how to call a C program when my users log in
my computer. The objective is: stop a user when he has oversteped
his acess hours.

I have a Livingston Portmaster 2eR runing RADIUS on Linux
Slackware 3.0.

Thanks.

P.S.: Sorry the poor English.

Marcos.