Why are you using Perl to drive EXPECT to do SFTP work? I would think it would be much easier to use Perl to drive a SFTP client to download the file and then use Perl to move it. I process several thousand files a day this way. The SFT client is PSFTP, I fire it once to do a grab of the available files which gets stashed in a temp file. I use Perl to parse that file to pull out the file names and do a second call to PSFTP to download the specific files into a temp folder. I then delete the files from the SFT server and go through the temp folder and move the files to the appropriate destination. Has worked great for many years now.