tty记录和回放工具，记录指定tty的输入输出，并按照时间发生序列在字符模式回放。 -ttyrec is a tty recorder. ttyplay is a tty player. Installation: make or if your system is SVR4 system (Solaris etc.), make CFLAGS=-DSVR4 or if your system supports getpt(3