客户端是一个带有2个参数的程序：

*日志服务器的主机名
*日志记录服务器的端口号

启动后，它将连接到服务器并从中读取消息
STDIN。 每条消息都是一个没有0字节的字符串。 消息是
由换行符\ n终止 什么都没有读
不再收到SIGINT或收到SIGTERM，它会关闭
连接并以返回码0终止。(The client is a program that takes 2 arguments:

* A hostname of a logging server
* A port number of the logging server

After it started, it will connect to the server and read messages from
STDIN. Every message is a string without 0 bytes. Messages are
terminated by a newline character \n. When there is nothing to read
anymore or SIGINT, or SIGTERM is received, it will close the
connection and terminate with return code 0.)