Detecting running deamons

I have a application that run like a deamon, which write in a file its PID,
that is used to stop it later by others programs. But, I ve noted that my
users send signal 9 to stop deamons, and my application cannot remove its
PID file, because it cannot handle singal 9, keeping its PID file at HD
(FileSystem).

Can someone sugest me a way to know the deamon's PID, without write it to a
file ?
OR
How can I do to know if my deamon is running and get its PID ?

Thanks,

Luciano