converting perl file handle into C FILE *


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converting perl file handle into C FILE *

by kamesh3183 (Beadle)

on Aug 31, 2005 at 18:09 UTC ( #488179=perlquestion: print w/ replies, xml )

Need Help??

kamesh3183 has asked for the wisdom of the Perl Monks concerning the following question:

Dear monks,
I am writing a wrapper for a C function:
int fun1(FILE *, char *);

Can somebody tell me how to convert the Perl filehandle into a C FILE * ?
presently I am using code like this:

arg1 = IoIFP(sv_2io(ST(1)); 
[download]

but the IoIFP is returning struct _PerlIO * type. Can anybody tell me how can I convert into FILE *?
Thanks
Kamesh

Comment on converting perl file handle into C FILE * Download Code
Re: converting perl file handle into C FILE * by merlyn (Sage) on Aug 31, 2005 at 18:12 UTC
If you're using PerlIO instead of STDIO, you probably won't be able to do what you want, because the buffer layout is likely incompatible. If all you want is a FILE * that is open on the same filedescriptor (which means that buffered I/O will almost certainly be broken), you can get the fileno from Perl, then create a FILE * on that using fdopen(3). That's probably not very safe though, because Perl will eventually close the handle leaving your FILE * pointing at a dead handle. -- Randal L. Schwartz, Perl hacker Be sure to read my standard disclaimer if this is a reply.	[reply]
Re: converting perl file handle into C FILE * by Roger (Parson) on Aug 31, 2005 at 18:14 UTC
You can use the XS::Typemap module, and use the convertion function T_STDIO to convert perl I/O structure to FILE * structure to pass to your XS.	[reply]

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