FileZilla Forums

We recently upgraded to FileZilla Server v1.7.1. Several appliances that used the old FileZilla Server stopped working. The main problem seems to be that FileZilla Server no longer supports the LIST command. Since we can't change the scanners and plotters, is it possible to enable the LIST command again?

The LIST command is fully supported in accordance with the FTP specifications.

boco wrote: ↑

2023-06-06 18:43

The LIST command is fully supported in accordance with the FTP specifications.

Then why does it tell me 'Invalid command.'?

230 Login successful.
ftp> LIST
Invalid command.
ftp> LIST -a
Invalid command.
ftp> ?
Commands may be abbreviated. Commands are:

! delete literal prompt send
? debug ls put status
append dir mdelete pwd trace
ascii disconnect mdir quit type
bell get mget quote user
binary glob mkdir recv verbose
bye hash mls remotehelp
cd help mput rename
close lcd open rmdir
ftp>

You are using a command line client to connect to the server, hence it's the client that doesn't support the "LIST" command.

oibaf wrote: ↑

2023-06-06 19:42

You are using a command line client to connect to the server, hence it's the client that doesn't support the "LIST" command.

I was using command line client as an example. However, the actual command being used by the hardware appliances is 'LIST -a'. This command is rejected under FileZilla Server 1.7.1 but was allowed by previous versions of FileZilla Server. Can we at least have an option in FileZilla Server that will process the LIST command even when it has the '-a' option?

Since we can't change the scanners and plotters, is it possible to enable the LIST command again?

I believe you may be "between a rock and a hard place". RFC959 does not define "-a" as a part of the LIST command:
https://datatracker.ietf.org/doc/html/rfc959 page 33.

There have been numerous posts about the LIST command since the new version of FileZilla server came out.

LIST -a

means

"list an item with the name -a"

As -a is a perfectly valid file or path name, even under Windows, -a cannot be a parameter.

What you can use:
LIST → lists all items in the current directory
LIST <file or path name> → lists the given file or path, if it exists.

What you must not use:
LIST with any parameters → there were NEVER supported by the FTP specs, thus they are not officially FTP
LIST with any wildcards * or ? → same, they were NEVER part of the specs


The appliances have a faulty FTP implementation that relies on unspecified, unofficial functionality (that is therefore not FTP at all). If you really cannot change them, you need to find a custom fileserver supporting this unofficial LIST stuff. Sorry.

boco wrote: ↑

2023-06-06 21:23

find a custom fileserver supporting this unofficial LIST stuff. Sorry.

I understand your position, but I don't agree with it. Sticking to a strict interpretation of the rules is not a pragmatic world view. I'm never going to be able to convince HP and BitDefender to change their FTP process so I'll just look for an FTP server implementation that supports common (but faulty) implementations.

Thank you

I understand your position, but I don't agree with it.

That's not my personal opinion, but as a staff member, I have to represent the general mindset of the project. Personally, I'd just make it configurable, provide ample warning, and let the user deal with the fallout, if there will be any.

That's not my personal opinion, but as a staff member, I have to represent the general mindset of the project. Personally, I'd just make it configurable, provide ample warning, and let the user deal with the fallout, if there will be any.

It is indeed awkward when a product suddenly drops a feature that customers had not realized was critical to their daily operation. If the original FileZilla server had never supported that "-a" feature, then people using those HP and BitDefender products would not have selected it.

One solution might be to go back to the beta version, at least until a suitable replacement can be found.

Sadly one of my biggest mistakes was implementing such non-standard behavior in the 0.9.x beta [*] versions. Fortunately this has been addressed in the non-beta releases of FZS which no longer suffer from this issue.

[*]beta: test, but don't use in production, functionality may change, it's wrong to rely on it.