If the condition evaluates to FALSE or NULL, the loop is bypassed, and control passes to the next statement.

如果条件的求值结果为FALSE或NULL，那么将绕过循环，并且控制被传递给下一条语句。

youdao

When the output is complete, the stream is flushed by writing a NULL object to the client stream and loop awaiting the next client.

输出完成后，通过向客户端流写入一个 NULL 对象，而且循环等待下一个客户端，从而刷新流。

youdao

It returns NULL, defined in stdio.h, for either error or EOF [end-of-file]; after the loop, we check for which one occurred.

对于错误或EOF[文件结束]，它都返回NULL，这是在stdio . h中定义的；循环结束后，我们会检查究竟是哪种情况。

youdao