title: Automating password fails when using lftp -u username, passwd
body: <p>My question is when using lftp to download file from a sftp site with automating password :</p>
  
  <pre><code>lftp -e 'set xfer:clobber on; mget -c one_file' -u username,passwd  sftp://hostname
  </code></pre>
  
  <p>lftp still prompt "Enter your PASSWORD:" to ask me the password. My operating system is Windows xp. Can anybody tell me what is problem ?</p>
  
  <p>Background:
  I want to transfer large files automatically from a sftp site when some condition is met. I find lftp is a good tool to transfer large files because it can resume the transfer in background when the link is disconnected due to the instable net connect status. I use python on Windows to control lftp to download the large files. But it seems to automating password in lftp is failed. I also try the expect-like method, such as winpexpect, but it seems can't solve this problem. However, I find others use lftp -u to automate password for sftp site when doing google searching, why it failed here ?</p>
  
  <p>Thank you in advance!</p>