On Wed, May 17, 2017 at 2:39 PM, Tom Lane <[email protected]> wrote: > Vaishnavi Prabakaran <[email protected]> writes: >>> Tom Lane wrote: >>>> BTW, it would be a good idea for somebody to check this out on Windows, >>>> assuming there's a way to generate a keyboard EOF signal there. > >> Ctrl-Z + Enter in windows generates EOF signal. I verified this issue and >> it is not reproducible in windows. > > Thanks for checking. So that's two major platforms where it works "as > expected" already.
Ah... the reason this is happening is that BSD-derived fread()
implementations return immediately if the EOF flag is set[1], but
others do not. At a guess, not doing that is probably more conformant
with POSIX ("... less than nitems only if a read error or end-of-file
is *encountered*", which seems to refer to the underlying condition
and not the user-clearable EOF flag).
We are neither clearing nor checking the EOF flag explicitly, and that
only works out OK on fread implementation that also ignore it.
Tom Lane <[email protected]> wrote (further upstream):
> If we're going
> to go out of our way to make it work, should we mention it in psql-ref?
I went looking for the place to put that and found that it already says:
For <literal>\copy ... from stdin</>, data rows are read from the same
source that issued the command, continuing until <literal>\.</literal>
is read or the stream reaches <acronym>EOF</>.
That's probably referring to the "outer" stream, such as a file that
contains the COPY ... FROM STDIN command, but doesn't it seem like a
general enough statement to cover ^d in the interactive case too?
Here's a version incorporating your other suggestions and a comment to explain.
[1]
https://github.com/freebsd/freebsd/blob/afbef1895e627cd1993428a252d39b505cf6c085/lib/libc/stdio/refill.c#L79
--
Thomas Munro
http://www.enterprisedb.com
clear-copy-stream-eof-v2.patch
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