文件传输

我想编写一个小程序用来在两台服务器之间定时(sftp)使用传输文件。
system ("sftp xxx")
可是我怎么能够让程序自动读入密码进行连接了？
清高手指点。

man 来的
[code]
The final usage format allows for automated sessions using the -b option.
     In such cases, it is usually necessary to configure public key authenti-
     cation to obviate the need to enter a password at connection time (see
     sshd(8) and ssh-keygen(1) for details).
[/code]
So.SSH打通应该就可以了.