scp密码输入自动化(expect)

下面的例子实现:从服务器(server)中下载备份(backupXXXX)存放到/home/admin/backup目录中,并只保留一个星期的备份文件.
#!/bin/sh
#getBackup.sh
export PATH=$PATH:/usr/local/sbin:/usr/sbin:/sbin:/usr/local/bin
PASSWORD=12345
/usr/bin/expect -c"
spawn scp root@server:/root/backup`date +%Y%m%d` /home/admin/backup
expect \"Enter passphrase for key '/home/admin/.ssh/id_rsa':\"
send \"$PASSWORD\r\"
send \"\r\"
interact
"
w=`date +\%Y\%m\%d -d"-7 day"`
rm -f /home//admin/backup/backup$w