Tassilo Parseval <[EMAIL PROTECTED]> writes:
>> >> >
>> >> > PerlIO *io;
>> >> > char mode[8];
>> >> > PerlIO_intmode2str(O_RDONLY|O_NONBLOCK, mode, NULL);
>> >> > io = PerlIO_fdopen(self->fd, mode);
PerlIO_intmode2str(O_RDONLY|O_NONBLOCK, mode, NULL);
>>
>> The O_NONBLOCK _may_ be confusing it.
>> And as thing is already open doesn't contribute much.
>
>Unfortunately, the O_NONBLOCK is essential in my case as this module
>provides access to all the ioctls of a CDROM-drive as permitted by the
>kernel. Otherwise I couldn't open a drive with no CD in it.
Fine - and you have opened it and got the fd.
PerlIO_fdopen then takes that already open fd and associates
a PerlIO * with it. PerlIO_intmde2str takes O_RDONLY and turns it
into stdio-like "r". Stdio and PerlIO have no way to represent O_NONBLOCK
so (having now looked) it just ignores it.
>
>I was just trying to reproduce the result of using the typemap. What was
>returned was not undef according to Devel::Peek. The funny thing now is:
>The above, which didn't work this morning, now works! I am seriously
>confused.
Any chance some other process had the CDROM in use "this morning"?
>
>It'd be nice having a bridge between Perl filehandles (that is,
>references to globs) and C handles (both file-descriptors and FILE*).
>Often C libraries work on filehandles but exposing those to pure Perl as
>glob-references is tricky. In particular, I wish we had
>
> PerlIO *PerlIO_importfd(int fd, int mode);
You do have:
PerlIO *PerlIO_fdopen(int fd, const char *);
What seems to be troubling us is getting a glob ref from one of those
so what we want is
SV *PerlIO_perlhandle(PerlIO *f);
>
>Going the other way (XSUB gets a glob-ref and needs FILE*/fd) isn't
>always smooth either.
First step is to get the IO * Perl_sv2io() does that.
Next you get your PerlIO * - you have a choice of two the one for output
and the one for input (often same but not for sockets or (some) ttys).
Getting a FILE * isn't smooth, but we have an API for that.
Getting a fd is just PerlIO_fileno(PerlIO *f)
>For that purpose, I made two macros:
>
> #ifdef _WIN32
> # define PerlIO_exportFILE(f,fl) ((FILE*)(f))
> #endif
>Especially the _WIN32 branch is fishy. But it was on this list that
>someone said that on windows a PerlIO* would just be an alias for FILE*.
It was on perl5.6 - not on perl5.8.
>
> #define sv_to_file(sv) (PerlIO_exportFILE(IoIFP(sv_2io(sv)), NULL))
>
That is "okay" anywhere with perl5.8+ - but please read the PODs.
In perl5.8+ there isn't necessarily a FILE * in normal perl IO.
So the above may have to
FILE *stdio = fdopen(PerlIO_fileno(pio),mode))
and how the FILE *stdio and PerlIO *pio interact is "messy".
