kill(2)

DESCRIPTION

send a signal to a process or process group

pid > 0 targets one process, pid == 0 targets the caller's
process group, and pid < 0 targets process group -pid. Signal
zero performs an existence check without enqueuing a signal.

SYNOPSIS

long kill(int pid, int signal);

RETURN VALUE

• Returns zero on success.

ERRORS

• -EINVAL
  • signal or target identifier is malformed.
• -ESRCH
  • no matching live process or process group exists.