expect之ssh登陆取回文件大小

#!/usr/bin/expect --

set timeout 30
#set name [lindex $argv 0]
#set pw [lindex $argv 1]
set name "mars"
set pw "password"
log_user 0
#log_file exp.log
spawn ssh $name@192.168.2.247
expect {
    "(yes/no)" {send "yes\r"}
    "password" {send "$pw\r"}
}
expect "mars"
    send "ls -l file | awk '{print \$5}'\r"
expect -re {.*\r\n(.*)\r\n.*}
    puts $expect_out(1,string)
    send "exit\r"
expect eof