Hacker News Reader

Comment by gruez | Hacker News Reader

Is there any meaningful difference between a ftp server and a http server with directory listing enabled?

With http you lose all the fun with active/passive FTP and tricks to get around firewalls. Though stateful firewalls already ruined it.

FTP had better support for doing server-server transfer - you could start a receiver on machine 2 and then trigger a transfer from machine 1 to machine 2 without using your own bandwidth. I guess you can achieve the same thing by doing curl on machine 2 in a screen session or something, but it feels a lot less elegant.

wow. I used ftp for years and even ran my own server for a while and never knew that was a thing. is that something that was actually used to mirror those sites? Debian mirrors certainly don't use this (anymore?) at least, for example..

It's called FXP: https://en.wikipedia.org/wiki/File_eXchange_Protocol

FlashFXP was a popular client that supported this: https://en.wikipedia.org/wiki/FlashFXP

It's called fxp and you can still find information on it. In the top site scene it was widely used.

I think scp can do stuff like this, I remember occasionally hitting it when wanting to move a file between two servers that can't talk to each other, expecting it would use my bandwidth/route for the transfer.

IIRC at least initially the FTP had some special modes to transfer binary data, whereas HTTP was not as efficient. And of course, HTTP was meant to be "pull only" whereas FTP had upload capabilities too.

The 'binary mode' of FTP just meant not to translate line endings or potentially character set, in opposition to 'text mode'.

The advantage with HTTP wasn't efficiency, it was that resuming interrupted downloads was typically possible with FTP but not HTTP (because ranged GET took a long while to get support in both servers and clients).

The difference between binary and text is deeper than just line endings and character set; PDP-10's, for example, stored text 5 7-bit characters to a 36-bit word. In text mode, it would unpack that to ASCII, whereas binary mode would pack two words into 9 bytes. If you transferred in the wrong mode, you'd just get an amorphous blob of protoplasm and need to transfer again

Actually I believe http was originally envisioned to be 2 way, a la webdav.

If it's unidirectional (user only downloads) and the files aren't crazy big, then given today's connection speeds and reliability I would say no not really.

Reply on news.ycombinator.com