PPP scripts
 

Hi,

I have a shell script that establishes a PPP connection. I have a ppp-on script that runs pppd and a ppp-on-dialer script that runs chat. I am getting confused here -

1) What processes should I look for to make sure that pppd and chat are running? I see /var/run/ppp0.pid sometimes, but sometimes its not there. There is also /var/run/pppd.tdb which doesn't go away irrespective of whether pppd is running or not. What is pppd.tdb file for?

2) What process corresponds to chat?

3) The ppp-on script starts ppp-on-dialer script. I run ppp-on script from my C function using system call. Using the following two lines, I can know the exit code of ppp-on.
int ret = system("./ppp-on")
printf("%d", WEXITSTATUS(ret));

But how can I know the return code of chat? This is how my chat script looks.

exec chat -v -s
ABORT 'RING'
ABORT 'NO CARRIER'
'' AT
TIMEOUT 3
OK ATD$TELEPHONE
TIMEOUT 45
CONNECT ''

4) Is there a way of specifying the number of times chat should try to establish connection before returning failure?

5) Should ppp-off script just try to kill ppp0.pid or also kill pppd.tdb?

Thanks for your help.

Ruchika