- Signal handlers (
Child process terminated, stopped or continued.
Terminal interrupt signal.
Terminal window size changed.
User-defined signal 1.
User-defined signal 2.
Immediately terminate a process. Cannot be caught or ignored, and the receiving process isn't able to perform any cleanup.
- Zombies can't be killed, since they're already dead. The parent must reap them.
- Blocked processes won't die until they next wake up.
Request process termination. Can be caught and interpreted or ignored by the receiving process, allowing for graceful termination.