Question

I’m trying to build a simple FTP server using Qt, but when I connect to it and type ‘ls’ using the Linux command line ftp client, I get the directory listing, but then there’s a warning at the end:

WARNING! 30 bare linefeeds received in ASCII mode

What does this warning mean, and how do I fix it?

Answer 1

From RFC959:

End-of-Line

  The end-of-line sequence defines the separation of printing
  lines.  The sequence is Carriage Return, followed by Line Feed.

All text you send using FTP should have newlines as "\r\n", which obviously you don’t have. You have to modify the text you send to the client, making sure it has correct line endings.