Ftp-WG: NLST vs MLSD

Frank da Cruz writes:
> For decades it has been possible for FTP clients to execute commands like:
>   mget pics/mae-west-*.jpg

And it's still possible. If you receive that command from the user,
simply switch to the pics directory, do an NLST, extract the mae-west-*
names, and retrieve those files one by one. What's the problem?

Are you saying that your client tries to push the * processing over to
the server? Sorry, but that isn't guaranteed by the FTP standard, and it
isn't supported by all servers. You should be using the standard NLST
mechanism instead.

The UNIX ftpd and its offshoot wuftpd have, historically, accounted for
most FTP servers on the Internet, but you shouldn't be relying on their
wildcard quirks. There have always been servers that, quite reasonably
and in full compliance with the protocol, don't imitate ftpd's wildcard
processing. You would already know this if you had tested your client
more thoroughly.

By the way, this is orthogonal to the question of list format.

> (in the "mae-west*.jpg" example
> above, suppose these pictures were in a directory that contained
> a million files, but you only wanted three of them).

Reality check: What kind of idiot organizes his files that way? Do you
realize how long it takes for a server to look through a million-file
directory on a typical filesystem? Have you heard of subdirectories?

---D. J. Bernstein, Associate Professor, Department of Mathematics,
Statistics, and Computer Science, University of Illinois at Chicago