Question

I am writing a daemon in c++ on linux which would launch
many processes. I’m considering a scenario when the daemon itself
is killed. On restarting the daemon, I would like to kill all
other processes launched by this daemon. Ideally I would like
all the processes created by this daemon to die if it is killed.
I’m considering a scenario when daemon dies after creating the
process and without writing onto the log file.

I was wondering if I could use /proc/proc_id/ kind of directories.
But in this case I would like these directories to be created
somewhere in my home directory. So, that I just scan them and
kill these processes. Is it possible ? Or if there is any other solution.

Note: I do not have the access to the source code of any of the
child process.

Answer 1

From the kill(2) man page:

   If pid is less than -1, then sig is sent to every process in  the  pro-
   cess group whose ID is -pid.