os.tmpfile() -> permission denied (Win XP)

[John Machin]

On Feb 11, 4:33 pm, "John Machin" <sjmac... at lexicon.net> wrote:
> On Feb 11, 4:15 pm, "Gabriel Genellina" <gagsl... at yahoo.com.ar> wrote:
>
> > En Sun, 11 Feb 2007 01:57:52 -0300, John Machin <sjmac... at lexicon.net>
> > escribió:
>
> > > | >>> os.tmpfile()
> > > Traceback (most recent call last):
> > >   File "<stdin>", line 1, in <module>
> > > OSError: [Errno 13] Permission denied
>
> > > 1. Before I start checking what permissions who has to do what to
> > > which, what directory is it likely to be trying to open the temp file
> > > in? C:\WINDOWS\TEMP....?
>
> > You could analyze the source,
>
> I have already followed the twisty little passages: os.tmpfile() is
> really nt.tempfile(), but there is no Modules/ntmodule.c (Modules/
> posixmodule.c does a Jekyll & Hyde trick). (nt|posix)module calls
> tmpfile(), which is (as I mentioned) in the C stdio library. How can I
> analyse the source of that? Have Microsoft had a rush of blood to the
> head and gone open source overnight??
>
> > but usually I find easier to use FILEMON:http://www.sysinternals.com
>
> Thanks, I'll try that.

While Filemon is still alive, it's been superceded by Procmon, which
combines filemon + regmon + plus new goodies. I tried procmon.

And the result of an administrator user doing os.tmpfile():
281773	4:50:14.8607126 PM	python.exe	2716	CreateFile	C:\t2ks	SUCCESS
Access: Generic Read/Write, Delete, Disposition: Create, Options:
Synchronous IO Non-Alert, Non-Directory File, Delete On Close,
Attributes: N, ShareMode: Read, Write, Delete, AllocationSize:
3,184,748,654,057,488,384
[big snip]

*** AARRGGHH It's creating the file in the *ROOT* directory ***

A quick google for "tmpfile root directory" reveals that this is a
"popular" problem on Windows. See e.g. http://bugs.mysql.com/bug.php?
id=3998 which has several users corroborating the story, plus this
handy hint:
"""
But MSDN says (ms-help://MS.MSDNQTR.2003APR.1033/vclib/html/
_crt_tmpfile.htm):
-------
The tmpfile function creates a temporary file and returns a pointer to
that stream. The temporary file is created in the root directory. To
create a temporary file in a directory other than the root, use tmpnam
or tempnam in conjunction with fopen.
"""

I wonder why my environment has entries for TMP and TEMP (both
pointing to the same path, and it sure ain't the root directory) --
must be one of those "haha fooled you" tricks :-(

Regards,
John