Why do we need a separate legacy protocol for file transfers?
What’s the benefit in keeping protocols for the sake of it?
What’s the benefit in keeping protocols for the sake of it?
Do we need browser support for it? It still happens now and then that a link will have an ftp target. That could be handled in the browser or it could open a separate url-handling application, as e.g. email or magnet urls do.
It uses separate "command" and "data" channels. The data channel is usually in the other direction, i.e. the client listens to a connection from the server when downloading a file. Passive mode, and an extra command for that, had to be implemented, and if the stars don't align right, it still ends up being a pain.
FTP also used to default to 7bit. If you did not explicitly switch to 8bit mode, you got corrupted downloads. This maybe made sense in a world with fundamentally different encodings, line endings, and where connection speeds were slow enough that downloading text files was a big task, but now?
Then, if I remember correctly, the file listing you got was not actually standardized, it could just be the output of the "ls" command on the server! FTP clients used to be dumb and just passed that output through to you, so it did not matter much. For smarter clients later, it did start to matter.
Finally, what does FTP actually offer that, in most cases, HTTP, and, in niche cases, rsync, scp or sftp do not offer?
This is not a bad thing in itself. It could enable you to download each file from a different, potentially better endpoint, while talking to the same server for coordination. It's just not the way we do it these days anymore - 3xx and anycast/CDNs solve that one to some extent. And NATs destroyed that idea being usable years ago. It's still fine in protocols like sip.
SFTP is actually not just FTP over SSH. The protocol is different precisely to get rid of a lot of the outdated nuisances.
As for rsync, sftp, scp those are heavily tied to ssh, rsync to the point that you actually ssh to host and call rsync command. rsync has a server mode as well, but almost no one uses it.
That aside, you can use FTP for auth and ACL in of which HTTP and rsync just aren't capable. I'm not sure this is a flaw in the core protocol so much as the tooling, but there you have it. FTP config syntax may often be byzantine. But it's widely supported (especially on old, low-spec, or embedded devices). For newer stuff, yeah sftp is probably better. But it's still got its uses.
That’s not the point we are discussing though; This is specifically regarding Chromium supporting FTP.