Select hangs after some reads

Donn Cave donn at
Thu Jun 8 20:59:37 CEST 2006

In article <mailman.6761.1149790756.27775.python-list at>,
 Steve Holden <steve at> wrote:

> The PSH flag indicates that the data stream must be flushed right 
> through to the other end. This is essential for interactive protocols 
> such as FTP: without it the server has no way to know that the client 
> has sent a complete command, and vice versa.

So you would expect to see this done explicitly in the source
for an FTP client or server implementation -- something that
sets this PSH flag or else the protocol won't work?  Or am
I misunderstanding what you mean?

I don't see that specific string anywhere in a the particular
FTP implementation whose source happened to be handy, basically
a Berkeley 4.4 variant as I think most are on UNIX.  Somewhere
around here I have a pass-through FTP client/server application
that adds GSSAPI-Kerberos5 authentication to the protocol traffic,
and I don't remember needing to do any such thing there.

I'd have to look harder at the details, but as I recall it,
like any sane application the protocol is defined in terms of
data, so you know if you have a complete command by looking at
what you have.

   Donn Cave, donn at

More information about the Python-list mailing list