事件：'exit'

¥Event: 'exit'

• code <number> 如果子进程自行退出，则退出代码。

  ¥code <number> The exit code if the child process exited on its own.

• signal <string> 终止子进程的信号。

  ¥signal <string> The signal by which the child process was terminated.

'exit' 事件在子进程结束后触发。如果进程退出，则 code 为进程的最终退出码，否则为 null。如果进程因收到信号而终止，则 signal 是信号的字符串名称，否则为 null。两者之一将始终是非 null。

¥The 'exit' event is emitted after the child process ends. If the process exited, code is the final exit code of the process, otherwise null. If the process terminated due to receipt of a signal, signal is the string name of the signal, otherwise null. One of the two will always be non-null.

触发 'exit' 事件时，子进程 stdio 流可能仍处于打开状态。

¥When the 'exit' event is triggered, child process stdio streams might still be open.

Node.js 为 SIGINT 和 SIGTERM 建立信号处理程序，Node.js 进程不会因为收到这些信号而立即终止。相反，Node.js 将执行一系列清理操作，然后重新触发已处理的信号。

¥Node.js establishes signal handlers for SIGINT and SIGTERM and Node.js processes will not terminate immediately due to receipt of those signals. Rather, Node.js will perform a sequence of cleanup actions and then will re-raise the handled signal.

请参阅 waitpid(2)。

¥See waitpid(2).