shell脚本中使用expect，自动scp操作

[liuyx@higinet ~]$ cat liu.sh
#!/usr/bin/expect -f
set user [lindex $argv 0]
set pass [lindex $argv 1]
set ip [lindex $argv 2]
if {$argc<3} {
        puts stderr "Usage: $argv0  user password ip.\n "
        exit 1
}
set timeout 30
spawn scp -r aa.txt
while {1} {
        expect {
                "Are you sure you want to continue connecting (yes/no)?" {
                        send "yes\r"
                }
                "password:" {
                        send "$pass\r"
                }
                "Permission denied*" {
                        break
                }
                "*No route to host" {
                        break
                }
                "*No such file or directory" {
                        break
                }
                timeout {
                        break
                }
                eof {
                        break
                }
        }
}
#expect eof
#interact
exit 0