使用Expect在SCP中传递多密码实现远程文件传输失败求助

1. 处理首次连接的主机密钥确认 #

首次连接远程主机时，scp会弹出主机密钥确认提示（如Are you sure you want to continue connecting (yes/no)?），这会导致expect匹配不到密码提示而卡住。修改脚本加入该场景的处理：

#!/usr/bin/expect

set timeout -1

spawn scp -3 scp://remote_source_user@host1:port1/home/source/test.txt scp://remote_target_user@host2:port2/home/target/

# 处理源主机的密钥确认和密码提示
expect {
    "Are you sure you want to continue connecting (yes/no)?" {
        send "yes\r"
        exp_continue
    }
    "remote_source_user@host1's password:" {
        send "SOURCE_PASSWORD\r"
    }
}

# 处理目标主机的密钥确认和密码提示
expect {
    "Are you sure you want to continue connecting (yes/no)?" {
        send "yes\r"
        exp_continue
    }
    "remote_target_user@host2's password:" {
        send "TARGET_PASSWORD\r"
    }
}

expect eof

2. 使用通用匹配模式提升兼容性 #

避免硬编码完整的提示文本，改用模糊匹配，同时支持动态变量配置：

#!/usr/bin/expect

set timeout -1
set src_user "remote_source_user"
set src_pass "SOURCE_PASSWORD"
set dst_user "remote_target_user"
set dst_pass "TARGET_PASSWORD"
set src_host "host1"
set src_port "port1"
set dst_host "host2"
set dst_port "port2"

spawn scp -3 scp://$src_user@$src_host:$src_port/home/source/test.txt scp://$dst_user@$dst_host:$dst_port/home/target/

expect {
    "*$src_user@*'s password:" {
        send "$src_pass\r"
        exp_continue
    }
    "*$dst_user@*'s password:" {
        send "$dst_pass\r"
        exp_continue
    }
    "Are you sure you want to continue connecting (yes/no)?" {
        send "yes\r"
        exp_continue
    }
    eof
}

3. 开启调试模式定位问题 #

在脚本开头添加exp_internal 1开启调试输出，可查看expect实际接收到的所有交互内容，快速定位匹配失败的原因：

#!/usr/bin/expect
exp_internal 1  # 开启调试输出，会打印所有交互细节
set timeout -1

# 后续脚本内容不变

内容的提问来源于stack exchange，提问作者user275616