No, -1 is simply the process group with pgid 1: https://stackoverflow.com/questions/392022/whats-the-best-way-to-send-a-signal-to-all-members-of-a-process-grou

No, -1 is simply the process group with pgid 1: https://stackoverflow.com/questions/392022/whats-the-best-way-to-send-a-signal-to-all-members-of-a-process-group https://stackoverflow.com/questions/392022/whats-the-best-wa... The problem is that -DIGIT doubles as both "signal number" and process group. The right way to invoke kill for a process group however would be "kill [OPTS]... -- -PGID".