Computer System, Computer Science, Operating Systems.
exactly one process group, which is identified by a positive integer process group ID. 每个进程只属于一个进程组，由正整数ID标识。子进程和父进程默认属于同一进程组。 The /bin/kill program sends an arbitrary signal to another process. kill进程时pid为正只发给对应进程，为0时发给调用kill的进程所在进程组所有进程，包括自己。pid小于0表示发信号给进程组|pid|中每个进程。 Receiving Signals 接收信号 When