ftplib CLI fails to retrieve files

[serhiy-storchaka]

Bug report

The ftplib module has undocumented feature -- a CLI that implements a simple FTP client. It allows listing directories and retrieving files. But retrieving files does not work in Python 3, because it writes binary data to sys.stdout.

It's help is also incomplete and unclear.

Documenting, testing and extending this CLI to a more complete FTP client is a matter of other issues. Here I only want to fix small functionality that it currently has.

Linked PRs

• gh-114241: Fix retrieving files in the ftplib CLI #114242
• [3.12] gh-114241: Fix and improve the ftplib CLI (GH-114242) #114404
• [3.11] gh-114241: Fix and improve the ftplib CLI (GH-114242) #114405

[tom93]

A couple more small bugs if anyone wants to look into this:

• There are two calls to sys.stderr.write where a trailing \n should be inserted.
• The line userid, acct, passwd = netrcobj.authenticators(host) fails with "TypeError: cannot unpack non-iterable NoneType object" if the netrc file exists but doesn't contain a host/default entry. Per the docs (and source), authenticators() returns None if there is no entry, so ftplib should check if the result is None instead of using except KeyError:.

[erlend-aasland]

Documenting, testing and extending this CLI to a more complete FTP client is a matter of other issues.

I'm looking into improving the docs.