killpg - send signal to all members of a process group
int killpg(pid_t pgrp, int signal);
The killpg() function causes signal signal to be sent to all the processes in the process group pgrp or to the processes own process group if pgrp is equal to zero.
If pgrp is greater than 1, it is equivalent to
The value returned is -1 on error, or 0 for success.
Errors are returned in errno and can be one of the following:
EINVAL for an invalid signal, EPERM if the userid of the calling process is not equal to that of the process the signal is sent to, and the userid is not that of the superuser. ESRCH for a process group which does not exist, and
kill(2), signal(2), sigqueue(2), signal(7)