shell脚本登陆的问题

寒鸦

HP-UX 11.11

我用如下脚本登陆系统

(sleep 1;
echo "username";
sleep 6;
echo "password";
sleep 3;
...) |telnet myhpux

提示:
Trying myhpux...
Connected to 10.0.0.1.
Escape character is '^]'.

HP-UX myhpux B.11.11 U 9000/800 (th)

login: username
Password: Connection closed by foreign host.

而我如果手动TELNET的话是可以登陆的,这是为什么?